编译错误,[Fatal Error] Could not create output file 如何改?

ady007 2001-05-26 08:36:00
编译错误,[Fatal Error] Could not create output file 如何改?
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WuHeHai 2001-05-26
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大不了,重新打开Delphi。再不行,充启系统。
wangguol 2001-05-26
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把杀毒的关掉
summernightrain 2001-05-26
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不能创建输出文件,那一定是该文件正被使用了.
yypp 2001-05-26
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你这个程序已经在运行了!
你重新编译的时候不能覆盖上一次编译好的.exe 文件。
退出你的程序,然后再重新编译就OK
dana 2001-05-26
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请具体一点否则不可能知道是为什么?可能性有很多.
笔记本的风扇控制 ---------------------------------------- 09 November 2006. Summary of changes for version 20061109: 1) ACPI CA Core Subsystem: Optimized the Load ASL operator in the case where the source operand is an operation region. Simply map the operation region memory, instead of performing a bytewise read. (Region must be of type SystemMemory, see below.) Fixed the Load ASL operator for the case where the source operand is a region field. A buffer object is also allowed as the source operand. BZ 480 Fixed a problem where the Load ASL operator allowed the source operand to be an operation region of any type. It is now restricted to regions of type SystemMemory, as per the ACPI specification. BZ 481 Additional cleanup and optimizations for the new Table Manager code. AcpiEnable will now fail if all of the required ACPI tables are not loaded (FADT, FACS, DSDT). BZ 477 Added #pragma pack(8/4) to acobject.h to ensure that the structures in this header are always compiled as aligned. The ACPI_OPERAND_OBJECT has been manually optimized to be aligned and will not work if it is byte-packed. Example Code and Data Size: These are the sizes for the OS- independent acpica.lib produced by the Microsoft Visual C++ 6.0 32- bit compiler. The debug version of the code includes the debug output trace mechanism and has a much larger code and data size. Previous Release: Non-Debug Version: 78.1K Code, 17.1K Data, 95.2K Total Debug Version: 155.4K Code, 63.1K Data, 218.5K Total Current Release: Non-Debug Version: 77.9K Code, 17.0K Data, 94.9K Total Debug Version: 155.2K Code, 63.1K Data, 218.3K Total 2) iASL Compiler/Disassembler and Tools: Fixed a problem where the presence of the _OSI predefined control method within complex expressions could cause an internal compiler error. AcpiExec: Implemented full region support for multiple address spaces. SpaceId is now part of the REGION object. BZ 429 ---------------------------------------- 11 Oc
Contents Overview 1 Lesson 1: Concepts – Locks and Lock Manager 3 Lesson 2: Concepts – Batch and Transaction 31 Lesson 3: Concepts – Locks and Applications 51 Lesson 4: Information Collection and Analysis 63 Lesson 5: Concepts – Formulating and Implementing Resolution 81 Module 4: Troubleshooting Locking and Blocking Overview At the end of this module, you will be able to:  Discuss how lock manager uses lock mode, lock resources, and lock compatibility to achieve transaction isolation.  Describe the various transaction types and how transactions differ from batches.  Describe how to troubleshoot blocking and locking issues.  Analyze the output of blocking scripts and Microsoft® SQL Server™ Profiler to troubleshoot locking and blocking issues.  Formulate hypothesis to resolve locking and blocking issues. Lesson 1: Concepts – Locks and Lock Manager This lesson outlines some of the common causes that contribute to the perception of a slow server. What You Will Learn After completing this lesson, you will be able to:  Describe locking architecture used by SQL Server.  Identify the various lock modes used by SQL Server.  Discuss lock compatibility and concurrent access.  Identify different types of lock resources.  Discuss dynamic locking and lock escalation.  Differentiate locks, latches, and other SQL Server internal “locking” mechanism such as spinlocks and other synchronization objects. Recommended Reading  Chapter 14 “Locking”, Inside SQL Server 2000 by Kalen Delaney  SOX000821700049 – SQL 7.0 How to interpret lock resource Ids  SOX000925700237 – TITLE: Lock escalation in SQL 7.0  SOX001109700040 – INF: Queries with PREFETCH in the plan hold lock until the end of transaction Locking Concepts Delivery Tip Prior to delivering this material, test the class to see if they fully understand the different isolation levels. If the class is not confident in their understanding, review appendix A04_Locking and its accompanying PowerPoint® file. Transactions in SQL Server provide the ACID properties: Atomicity A transaction either commits or aborts. If a transaction commits, all of its effects remain. If it aborts, all of its effects are undone. It is an “all or nothing” operation. Consistency An application should maintain the consistency of a database. For example, if you defer constraint checking, it is your responsibility to ensure that the database is consistent. Isolation Concurrent transactions are isolated from the updates of other incomplete transactions. These updates do not constitute a consistent state. This property is often called serializability. For example, a second transaction traversing the doubly linked list mentioned above would see the list before or after the insert, but it will see only complete changes. Durability After a transaction commits, its effects will persist even if there are system failures. Consistency and isolation are the most important in describing SQL Server’s locking model. It is up to the application to define what consistency means, and isolation in some form is needed to achieve consistent results. SQL Server uses locking to achieve isolation. Definition of Dependency: A set of transactions can run concurrently if their outputs are disjoint from the union of one another’s input and output sets. For example, if T1 writes some object that is in T2’s input or output set, there is a dependency between T1 and T2. Bad Dependencies These include lost updates, dirty reads, non-repeatable reads, and phantoms. ANSI SQL Isolation Levels An isolation level determines the degree to which data is isolated for use by one process and guarded against interference from other processes. Prior to SQL Server 7.0, REPEATABLE READ and SERIALIZABLE isolation levels were synonymous. There was no way to prevent non-repeatable reads while not preventing phantoms. By default, SQL Server 2000 operates at an isolation level of READ COMMITTED. To make use of either more or less strict isolation levels in applications, locking can be customized for an entire session by setting the isolation level of the session with the SET TRANSACTION ISOLATION LEVEL statement. To determine the transaction isolation level currently set, use the DBCC USEROPTIONS statement, for example: USE pubs GO SET TRANSACTION ISOLATION LEVEL REPEATABLE READ GO DBCC USEROPTIONS GO Multigranular Locking Multigranular Locking In our example, if one transaction (T1) holds an exclusive lock at the table level, and another transaction (T2) holds an exclusive lock at the row level, each of the transactions believe they have exclusive access to the resource. In this scenario, since T1 believes it locks the entire table, it might inadvertently make changes to the same row that T2 thought it has locked exclusively. In a multigranular locking environment, there must be a way to effectively overcome this scenario. Intent lock is the answer to this problem. Intent Lock Intent Lock is the term used to mean placing a marker in a higher-level lock queue. The type of intent lock can also be called the multigranular lock mode. An intent lock indicates that SQL Server wants to acquire a shared (S) lock or exclusive (X) lock on some of the resources lower down in the hierarchy. For example, a shared intent lock placed at the table level means that a transaction intends on placing shared (S) locks on pages or rows within that table. Setting an intent lock at the table level prevents another transaction from subsequently acquiring an exclusive (X) lock on the table containing that page. Intent locks improve performance because SQL Server examines intent locks only at the table level to determine whether a transaction can safely acquire a lock on that table. This removes the requirement to examine every row or page lock on the table to determine whether a transaction can lock the entire table. Lock Mode The code shown in the slide represents how the lock mode is stored internally. You can see these codes by querying the master.dbo.spt_values table: SELECT * FROM master.dbo.spt_values WHERE type = N'L' However, the req_mode column of master.dbo.syslockinfo has lock mode code that is one less than the code values shown here. For example, value of req_mode = 3 represents the Shared lock mode rather than the Schema Modification lock mode. Lock Compatibility These locks can apply at any coarser level of granularity. If a row is locked, SQL Server will apply intent locks at both the page and the table level. If a page is locked, SQL Server will apply an intent lock at the table level. SIX locks imply that we have shared access to a resource and we have also placed X locks at a lower level in the hierarchy. SQL Server never asks for SIX locks directly, they are always the result of a conversion. For example, suppose a transaction scanned a page using an S lock and then subsequently decided to perform a row level update. The row would obtain an X lock, but now the page would require an IX lock. The resultant mode on the page would be SIX. Another type of table lock is a schema stability lock (Sch-S) and is compatible with all table locks except the schema modification lock (Sch-M). The schema modification lock (Sch-M) is incompatible with all table locks. Locking Resources Delivery Tip Note the differences between Key and Key Range locks. Key Range locks will be covered in a couple of slides. SQL Server can lock these resources: Item Description DB A database. File A database file Index An entire index of a table. Table An entire table, including all data and indexes. Extent A contiguous group of data pages or index pages. Page An 8-KB data page or index page. Key Row lock within an index. Key-range A key-range. Used to lock ranges between records in a table to prevent phantom insertions or deletions into a set of records. Ensures serializable transactions. RID A Row Identifier. Used to individually lock a single row within a table. Application A lock resource defined by an application. The lock manager knows nothing about the resource format. It simply compares the 'strings' representing the lock resources to determine whether it has found a match. If a match is found, it knows that resource is already locked. Some of the resources have “sub-resources.” The followings are sub-resources displayed by the sp_lock output: Database Lock Sub-Resources: Full Database Lock (default) [BULK-OP-DB] – Bulk Operation Lock for Database [BULK-OP-LOG] – Bulk Operation Lock for Log Table Lock Sub-Resources: Full Table Lock (default) [UPD-STATS] – Update statistics Lock [COMPILE] – Compile Lock Index Lock sub-Resources: Full Index Lock (default) [INDEX_ID] – Index ID Lock [INDEX_NAME] – Index Name Lock [BULK_ALLOC] – Bulk Allocation Lock [DEFRAG] – Defragmentation Lock For more information, see also… SOX000821700049 SQL 7.0 How to interpret lock resource Ids Lock Resource Block The resource type has the following resource block format: Resource Type (Code) Content DB (2) Data 1: sub-resource; Data 2: 0; Data 3: 0 File (3) Data 1: File ID; Data 2: 0; Data 3: 0 Index (4) Data 1: Object ID; Data 2: sub-resource; Data 3: Index ID Table (5) Data 1: Object ID; Data 2: sub-resource; Data 3: 0. Page (6) Data 1: Page Number; Data 3: 0. Key (7) Data 1: Object ID; Data 2: Index ID; Data 3: Hashed Key Extent (8) Data 1: Extent ID; Data 3: 0. RID (9) Data 1: RID; Data 3: 0. Application (10) Data 1: Application resource name The rsc_bin column of master..syslockinfo contains the resource block in hexadecimal format. For an example of how to decode value from this column using the information above, let us assume we have the following value: 0x000705001F83D775010002014F0BEC4E With byte swapping within each field, this can be decoded as: Byte 0: Flag – 0x00 Byte 1: Resource Type – 0x07 (Key) Byte 2-3: DBID – 0x0005 Byte 4-7: ObjectID – 0x 75D7831F (1977058079) Byte 8-9: IndexID – 0x0001 Byte 10-16: Hash Key value – 0x 02014F0BEC4E For more information about how to decode this value, see also… Inside SQL Server 2000, pages 803 and 806. Key Range Locking Key Range Locking To support SERIALIZABLE transaction semantics, SQL Server needs to lock sets of rows specified by a predicate, such as WHERE salary BETWEEN 30000 AND 50000 SQL Server needs to lock data that does not exist! If no rows satisfy the WHERE condition the first time the range is scanned, no rows should be returned on any subsequent scans. Key range locks are similar to row locks on index keys (whether clustered or not). The locks are placed on individual keys rather than at the node level. The hash value consists of all the key components and the locator. So, for a nonclustered index over a heap, where columns c1 and c2 where indexed, the hash would contain contributions from c1, c2 and the RID. A key range lock applied to a particular key means that all keys between the value locked and the next value would be locked for all data modification. Key range locks can lock a slightly larger range than that implied by the WHERE clause. Suppose the following select was executed in a transaction with isolation level SERIALIZABLE: SELECT * FROM members WHERE first_name between ‘Al’ and ‘Carl’ If 'Al', 'Bob', and 'Dave' are index keys in the table, the first two of these would acquire key range locks. Although this would prevent anyone from inserting either 'Alex' or 'Ben', it would also prevent someone from inserting 'Dan', which is not within the range of the WHERE clause. Prior to SQL Server 7.0, page locking was used to prevent phantoms by locking the entire set of pages on which the phantom would exist. This can be too conservative. Key Range locking lets SQL Server lock only a much more restrictive area of the table. Impact Key-range locking ensures that these scenarios are SERIALIZABLE:  Range scan query  Singleton fetch of nonexistent row  Delete operation  Insert operation However, the following conditions must be satisfied before key-range locking can occur:  The transaction-isolation level must be set to SERIALIZABLE.  The operation performed on the data must use an index range access. Range locking is activated only when query processing (such as the optimizer) chooses an index path to access the data. Key Range Lock Mode Again, the req_mode column of master.dbo.syslockinfo has lock mode code that is one less than the code values shown here. Dynamic Locking When modifying individual rows, SQL Server typically would take row locks to maximize concurrency (for example, OLTP, order-entry application). When scanning larger volumes of data, it would be more appropriate to take page or table locks to minimize the cost of acquiring locks (for example, DSS, data warehouse, reporting). Locking Decision The decision about which unit to lock is made dynamically, taking many factors into account, including other activity on the system. For example, if there are multiple transactions currently accessing a table, SQL Server will tend to favor row locking more so than it otherwise would. It may mean the difference between scanning the table now and paying a bit more in locking cost, or having to wait to acquire a more coarse lock. A preliminary locking decision is made during query optimization, but that decision can be adjusted when the query is actually executed. Lock Escalation When the lock count for the transaction exceeds and is a multiple of ESCALATION_THRESHOLD (1250), the Lock Manager attempts to escalate. For example, when a transaction acquired 1250 locks, lock manager will try to escalate. The number of locks held may continue to increase after the escalation attempt (for example, because new tables are accessed, or the previous lock escalation attempts failed due to incompatible locks held by another spid). If the lock count for this transaction reaches 2500 (1250 * 2), Lock Manager will attempt escalation again. The Lock Manager looks at the lock memory it is using and if it is more than 40 percent of SQL Server’s allocated buffer pool memory, it tries to find a scan (SDES) where no escalation has already been performed. It then repeats the search operation until all scans have been escalated or until the memory used drops under the MEMORY_LOAD_ESCALATION_THRESHOLD (40%) value. If lock escalation is not possible or fails to significantly reduce lock memory footprint, SQL Server can continue to acquire locks until the total lock memory reaches 60 percent of the buffer pool (MAX_LOCK_RESOURCE_MEMORY_PERCENTAGE=60). Lock escalation may be also done when a single scan (SDES) holds more than LOCK_ESCALATION_THRESHOLD (765) locks. There is no lock escalation on temporary tables or system tables. Trace Flag 1211 disables lock escalation. Important Do not relay this to the customer without careful consideration. Lock escalation is a necessary feature, not something to be avoided completely. Trace flags are global and disabling lock escalation could lead to out of memory situations, extremely poor performing queries, or other problems. Lock escalation tracing can be seen using the Profiler or with the general locking trace flag, -T1200. However, Trace Flag 1200 shows all lock activity so it should not be usable on a production system. For more information, see also… SOX000925700237 “TITLE: SQL 7.0 Lock escalation in SQL 7.0” Lock Timeout Application Lock Timeout An application can set lock timeout for a session with the SET option: SET LOCK_TIMEOUT N where N is a number of milliseconds. A value of -1 means that there will be no timeout, which is equivalent to the version 6.5 behavior. A value of 0 means that there will be no waiting; if a process finds a resource locked, it will generate error message 1222 and continue with the next statement. The current value of LOCK_TIMEOUT is stored in the global variable @@lock_timeout. Note After a lock timeout any transaction containing the statement, is rolled back or canceled by SQL Server 2000 (bug#352640 was filed). This behavior is different from that of SQL Server 7.0. With SQL Server 7.0, the application must have an error handler that can trap error 1222 and if an application does not trap the error, it can proceed unaware that an individual statement within a transaction has been canceled, and errors can occur because statements later in the transaction may depend on the statement that was never executed. Bug#352640 is fixed in hotfix build 8.00.266 whereby a lock timeout will only Internal Lock Timeout At time, internal operations within SQL Server will attempt to acquire locks via lock manager. Typically, these lock requests are issued with “no waiting.” For example, the ghost record processing might try to clean up rows on a particular page, and before it can do that, it needs to lock the page. Thus, the ghost record manager will request a page lock with no wait so that if it cannot lock the page, it will just move on to other pages; it can always come back to this page later. If you look at SQL Profiler Lock: Timeout events, internal lock timeout typically have a duration value of zero. Lock Duration Lock Mode and Transaction Isolation Level For REPEATABLE READ transaction isolation level, update locks are held until data is read and processed, unless promoted to exclusive locks. "Data is processed" means that we have decided whether the row in question matched the search criteria; if not then the update lock is released, otherwise, we get an exclusive lock and make the modification. Consider the following query: use northwind go dbcc traceon(3604, 1200, 1211) -- turn on lock tracing -- and disable escalation go set transaction isolation level repeatable read begin tran update dbo.[order details] set discount = convert (real, discount) where discount = 0.0 exec sp_lock Update locks are promoted to exclusive locks when there is a match; otherwise, the update lock is released. The sp_lock output verifies that the SPID does not hold any update locks or shared locks at the end of the query. Lock escalation is turned off so that exclusive table lock is not held at the end. Warning Do not use trace flag 1200 in a production environment because it produces a lot of output and slows down the server. Trace flag 1211 should not be used unless you have done extensive study to make sure it helps with performance. These trace flags are used here for illustration and learning purposes only. Lock Ownership Most of the locking discussion in this lesson relates to locks owned by “transactions.” In addition to transaction, cursor and session can be owners of locks and they both affect how long locks are held. For every row that is fetched, when SCROLL_LOCKS option is used, regardless of the state of a transaction, a cursor lock is held until the next row is fetched or when the cursor is closed. Locks owned by session are outside the scope of a transaction. The duration of these locks are bounded by the connection and the process will continue to hold these locks until the process disconnects. A typical lock owned by session is the database (DB) lock. Locking – Read Committed Scan Under read committed isolation level, when database pages are scanned, shared locks are held when the page is read and processed. The shared locks are released “behind” the scan and allow other transactions to update rows. It is important to note that the shared lock currently acquired will not be released until shared lock for the next page is successfully acquired (this is commonly know as “crabbing”). If the same pages are scanned again, rows may be modified or deleted by other transactions. Locking – Repeatable Read Scan Under repeatable read isolation level, when database pages are scanned, shared locks are held when the page is read and processed. SQL Server continues to hold these shared locks, thus preventing other transactions to update rows. If the same pages are scanned again, previously scanned rows will not change but new rows may be added by other transactions. Locking – Serializable Read Scan Under serializable read isolation level, when database pages are scanned, shared locks are held not only on rows but also on scanned key range. SQL Server continues to hold these shared locks until the end of transaction. Because key range locks are held, not only will this prevent other transactions from modifying the rows, no new rows can be inserted. Prefetch and Isolation Level Prefetch and Locking Behavior The prefetch feature is available for use with SQL Server 7.0 and SQL Server 2000. When searching for data using a nonclustered index, the index is searched for a particular value. When that value is found, the index points to the disk address. The traditional approach would be to immediately issue an I/O for that row, given the disk address. The result is one synchronous I/O per row and, at most, one disk at a time working to evaluate the query. This does not take advantage of striped disk sets. The prefetch feature takes a different approach. It continues looking for more record pointers in the nonclustered index. When it has collected a number of them, it provides the storage engine with prefetch hints. These hints tell the storage engine that the query processor will need these particular records soon. The storage engine can now issue several I/Os simultaneously, taking advantage of striped disk sets to execute multiple operations simultaneously. For example, if the engine is scanning a nonclustered index to determine which rows qualify but will eventually need to visit the data page as well to access columns that are not in the index, it may decide to submit asynchronous page read requests for a group of qualifying rows. The prefetch data pages are then revisited later to avoid waiting for each individual page read to complete in a serial fashion. This data access path requires that a lock be held between the prefetch request and the row lookup to stabilize the row on the page so it is not to be moved by a page split or clustered key update. For our example, the isolation level of the query is escalated to REPEATABLE READ, overriding the transaction isolation level. With SQL Server 7.0 and SQL Server 2000, portions of a transaction can execute at a different transaction isolation level than the entire transaction itself. This is implemented as lock classes. Lock classes are used to control lock lifetime when portions of a transaction need to execute at a stricter isolation level than the underlying transaction. Unfortunately, in SQL Server 7.0 and SQL Server 2000, the lock class is created at the topmost operator of the query and hence released only at the end of the query. Currently there is no support to release the lock (lock class) after the row has been discarded or fetched by the filter or join operator. This is because isolation level can be set at the query level via a lock class, but no lower. Because of this, locks acquired during the query will not be released until the query completes. If prefetch is occurring you may see a single SPID that holds hundreds of Shared KEY or PAG locks even though the connection’s isolation level is READ COMMITTED. Isolation level can be determined from DBCC PSS output. For details about this behavior see “SOX001109700040 INF: Queries with PREFETCH in the plan hold lock until the end of transaction”. Other Locking Mechanism Lock manager does not manage latches and spinlocks. Latches Latches are internal mechanisms used to protect pages while doing operations such as placing a row physically on a page, compressing space on a page, or retrieving rows from a page. Latches can roughly be divided into I/O latches and non-I/O latches. If you see a high number of non-I/O related latches, SQL Server is usually doing a large number of hash or sort operations in tempdb. You can monitor latch activities via DBCC SQLPERF(‘WAITSTATS’) command. Spinlock A spinlock is an internal data structure that is used to protect vital information that is shared within SQL Server. On a multi-processor machine, when SQL Server tries to access a particular resource protected by a spinlock, it must first acquire the spinlock. If it fails, it executes a loop that will check to see if the lock is available and if not, decrements a counter. If the counter reaches zero, it yields the processor to another thread and goes into a “sleep” (wait) state for a pre-determined amount of time. When it wakes, hopefully, the lock is free and available. If not, the loop starts again and it is terminated only when the lock is acquired. The reason for implementing a spinlock is that it is probably less costly to “spin” for a short time rather than yielding the processor. Yielding the processor will force an expensive context switch where:  The old thread’s state must be saved  The new thread’s state must be reloaded  The data stored in the L1 and L2 cache are useless to the processor On a single-processor computer, the loop is not useful because no other thread can be running and thus, no one can release the spinlock for the currently executing thread to acquire. In this situation, the thread yields the processor immediately. Lesson 2: Concepts – Batch and Transaction This lesson outlines some of the common causes that contribute to the perception of a slow server. What You Will Learn After completing this lesson, you will be able to:  Review batch processing and error checking.  Review explicit, implicit and autocommit transactions and transaction nesting level.  Discuss how commit and rollback transaction done in stored procedure and trigger affects transaction nesting level.  Discuss various transaction isolation level and their impact on locking.  Discuss the difference between aborting a statement, a transaction, and a batch.  Describe how @@error, @@transcount, and @@rowcount can be used for error checking and handling. Recommended Reading  Charter 12 “Transactions and Triggers”, Inside SQL Server 2000 by Kalen Delaney Batch Definition SQL Profiler Statements and Batches To help further your understanding of what is a batch and what is a statement, you can use SQL Profiler to study the definition of batch and statement.  Try This: Using SQL Profiler to Analyze Batch 1. Log on to a server with Query Analyzer 2. Startup the SQL Profiler against the same server 3. Start a trace using the “StandardSQLProfiler” template 4. Execute the following using Query Analyzer: SELECT @@VERSION SELECT @@SPID The ‘SQL:BatchCompleted’ event is captured by the trace. It shows both the statements as a single batch. 5. Now execute the following using Query Analyzer {call sp_who()} What shows up? The ‘RPC:Completed’ with the sp_who information. RPC is simply another entry point to the SQL Server to call stored procedures with native data types. This allows one to avoid parsing. The ‘RPC:Completed’ event should be considered the same as a batch for the purposes of this discussion. Stop the current trace and start a new trace using the “SQLProfilerTSQL_SPs” template. Issue the same command as outlines in step 5 above. Looking at the output, not only can you see the batch markers but each statement as executed within the batch. Autocommit, Explicit, and Implicit Transaction Autocommit Transaction Mode (Default) Autocommit mode is the default transaction management mode of SQL Server. Every Transact-SQL statement, whether it is a standalone statement or part of a batch, is committed or rolled back when it completes. If a statement completes successfully, it is committed; if it encounters any error, it is rolled back. A SQL Server connection operates in autocommit mode whenever this default mode has not been overridden by either explicit or implicit transactions. Autocommit mode is also the default mode for ADO, OLE DB, ODBC, and DB-Library. A SQL Server connection operates in autocommit mode until a BEGIN TRANSACTION statement starts an explicit transaction, or implicit transaction mode is set on. When the explicit transaction is committed or rolled back, or when implicit transaction mode is turned off, SQL Server returns to autocommit mode. Explicit Transaction Mode An explicit transaction is a transaction that starts with a BEGIN TRANSACTION statement. An explicit transaction can contain one or more statements and must be terminated by either a COMMIT TRANSACTION or a ROLLBACK TRANSACTION statement. Implicit Transaction Mode SQL Server can automatically or, more precisely, implicitly start a transaction for you if a SET IMPLICIT_TRANSACTIONS ON statement is run or if the implicit transaction option is turned on globally by running sp_configure ‘user options’ 2. (Actually, the bit mask 0x2 must be turned on for the user option so you might have to perform an ‘OR’ operation with the existing user option value.) See SQL Server 2000 Books Online on how to turn on implicit transaction under ODBC and OLE DB (acdata.chm::/ac_8_md_06_2g6r.htm). Transaction Nesting Explicit transactions can be nested. Committing inner transactions is ignored by SQL Server other than to decrements @@TRANCOUNT. The transaction is either committed or rolled back based on the action taken at the end of the outermost transaction. If the outer transaction is committed, the inner nested transactions are also committed. If the outer transaction is rolled back, then all inner transactions are also rolled back, regardless of whether the inner transactions were individually committed. Each call to COMMIT TRANSACTION applies to the last executed BEGIN TRANSACTION. If the BEGIN TRANSACTION statements are nested, then a COMMIT statement applies only to the last nested transaction, which is the innermost transaction. Even if a COMMIT TRANSACTION transaction_name statement within a nested transaction refers to the transaction name of the outer transaction, the commit applies only to the innermost transaction. If a ROLLBACK TRANSACTION statement without a transaction_name parameter is executed at any level of a set of nested transaction, it rolls back all the nested transactions, including the outermost transaction. The @@TRANCOUNT function records the current transaction nesting level. Each BEGIN TRANSACTION statement increments @@TRANCOUNT by one. Each COMMIT TRANSACTION statement decrements @@TRANCOUNT by one. A ROLLBACK TRANSACTION statement that does not have a transaction name rolls back all nested transactions and decrements @@TRANCOUNT to 0. A ROLLBACK TRANSACTION that uses the transaction name of the outermost transaction in a set of nested transactions rolls back all the nested transactions and decrements @@TRANCOUNT to 0. When you are unsure if you are already in a transaction, SELECT @@TRANCOUNT to determine whether it is 1 or more. If @@TRANCOUNT is 0 you are not in a transaction. You can also find the transaction nesting level by checking the sysprocess.open_tran column. See SQL Server 2000 Books Online topic “Nesting Transactions” (acdata.chm::/ac_8_md_06_66nq.htm) for more information. Statement, Transaction, and Batch Abort One batch can have many statements and one transaction can have multiple statements, also. One transaction can span multiple batches and one batch can have multiple transactions. Statement Abort Currently executing statement is aborted. This can be a bit confusing when you start talking about statements in a trigger or stored procedure. Let us look closely at the following trigger: CREATE TRIGGER TRG8134 ON TBL8134 AFTER INSERT AS BEGIN SELECT 1/0 SELECT 'Next command in trigger' END To fire the INSERT trigger, the batch could be as simple as ‘INSERT INTO TBL8134 VALUES(1)’. However, the trigger contains two statements that must be executed as part of the batch to satisfy the clients insert request. When the ‘SELECT 1/0’ causes the divide by zero error, a statement abort is issued for the ‘SELECT 1/0’ statement. Batch and Transaction Abort On SQL Server 2000 (and SQL Server 7.0) whenever a non-informational error is encountered in a trigger, the statement abort is promoted to a batch and transactional abort. Thus, in the example the statement abort for ‘select 1/0’ promotion results in an entire batch abort. No further statements in the trigger or batch will be executed and a rollback is issued. On SQL Server 6.5, the statement aborts immediately and results in a transaction abort. However, the rest of the statements within the trigger are executed. This trigger could return ‘Next command in trigger’ as a result set. Once the trigger completes the batch abort promotion takes effect. Conversely, submitting a similar set of statements in a standalone batch can result in different behavior. SELECT 1/0 SELECT 'Next command in batch' Not considering the set option possibilities, a divide by zero error generally results in a statement abort. Since it is not in a trigger, the promotion to a batch abort is avoided and subsequent SELECT statement can execute. The programmer should add an “if @@ERROR” check immediately after the ‘select 1/0’ to T-SQL execution to control the flow correctly. Aborting and Set Options ARITHABORT If SET ARITHABORT is ON, these error conditions cause the query or batch to terminate. If the errors occur in a transaction, the transaction is rolled back. If SET ARITHABORT is OFF and one of these errors occurs, a warning message is displayed, and NULL is assigned to the result of the arithmetic operation. When an INSERT, DELETE, or UPDATE statement encounters an arithmetic error (overflow, divide-by-zero, or a domain error) during expression evaluation when SET ARITHABORT is OFF, SQL Server inserts or updates a NULL value. If the target column is not nullable, the insert or update action fails and the user receives an error. XACT_ABORT When SET XACT_ABORT is ON, if a Transact-SQL statement raises a run-time error, the entire transaction is terminated and rolled back. When OFF, only the Transact-SQL statement that raised the error is rolled back and the transaction continues processing. Compile errors, such as syntax errors, are not affected by SET XACT_ABORT. For example: CREATE TABLE t1 (a int PRIMARY KEY) CREATE TABLE t2 (a int REFERENCES t1(a)) GO INSERT INTO t1 VALUES (1) INSERT INTO t1 VALUES (3) INSERT INTO t1 VALUES (4) INSERT INTO t1 VALUES (6) GO SET XACT_ABORT OFF GO BEGIN TRAN INSERT INTO t2 VALUES (1) INSERT INTO t2 VALUES (2) /* Foreign key error */ INSERT INTO t2 VALUES (3) COMMIT TRAN SELECT 'Continue running batch 1...' GO SET XACT_ABORT ON GO BEGIN TRAN INSERT INTO t2 VALUES (4) INSERT INTO t2 VALUES (5) /* Foreign key error */ INSERT INTO t2 VALUES (6) COMMIT TRAN SELECT 'Continue running batch 2...' GO /* Select shows only keys 1 and 3 added. Key 2 insert failed and was rolled back, but XACT_ABORT was OFF and rest of transaction succeeded. Key 5 insert error with XACT_ABORT ON caused all of the second transaction to roll back. Also note that 'Continue running batch 2...' is not Returned to indicate that the batch is aborted. */ SELECT * FROM t2 GO DROP TABLE t2 DROP TABLE t1 GO Compile and Run-time Errors Compile Errors Compile errors are encountered during syntax checks, security checks, and other general operations to prepare the batch for execution. These errors can prevent the optimization of the query and thus lead to immediate abort. The statement is not run and the batch is aborted. The transaction state is generally left untouched. For example, assume there are four statements in a particular batch. If the third statement has a syntax error, none of the statements in the batch is executed. Optimization Errors Optimization errors would include rare situations where the statement encounters a problem when attempting to build an optimal execution plan. Example: “too many tables referenced in the query” error is reported because a “work table” was added to the plan. Runtime Errors Runtime errors are those that are encountered during the execution of the query. Consider the following batch: SELECT * FROM pubs.dbo.titles UPDATE pubs.dbo.authors SET au_lname = au_lname SELECT * FROM foo UPDATE pubs.dbo.authors SET au_lname = au_lname If you run the above statements in a batch, the first two statements will be executed, the third statement will fail because table foo does not exist, and the batch will terminate. Deferred Name Resolution is the feature that allows this batch to start executing before resolving the object foo. This feature allows SQL Server to delay object resolution and place a “placeholder” in the query’s execution. The object referenced by the placeholder is resolved until the query is executed. In our example, the execution of the statement “SELECT * FROM foo” will trigger another compile process to resolve the name again. This time, error message 208 is returned. Error: 208, Level 16, State 1, Line 1 Invalid object name 'foo'. Message 208 can be encountered as a runtime or compile error depending on whether the Deferred Name Resolution feature is available. In SQL Server 6.5 this would be considered a compile error and on SQL Server 2000 (and SQL Server7.0) as a runtime error due to Deferred Name Resolution. In the following example, if a trigger referenced authors2, the error is detected as SQL Server attempts to execute the trigger. However, under SQL Server 6.5 the create trigger statement fails because authors2 does not exist at compile time. When errors are encountered in a trigger, generally, the statement, batch, and transaction are aborted. You should be able to observe this by running the following script in pubs database: Create table tblTest(iID int) go create trigger trgInsert on tblTest for INSERT as begin select * from authors select * from authors2 select * from titles end go begin tran select 'Before' insert into tblTest values(1) select 'After' go select @@TRANCOUNT go When run in a batch, the statement and the batch are aborted but the transaction remains active. The follow script illustrates this: begin tran select 'Before' select * from authors2 select 'After' go select @@TRANCOUNT go One other factor in a compile versus runtime error is implicit data type conversions. If you were to run the following statements on SQL Server 6.5 and SQL Server 2000 (and SQL Server 7.0): create table tblData(dtData datetime) go select 1 insert into tblData values(12/13/99) go On SQL Server 6.5, you get an error before execution of the batch begins so no statements are executed and the batch is aborted. Error: 206, Level 16, State 2, Line 2 Operand type clash: int is incompatible with datetime On SQL Server 2000, you get the default value (1900-01-01 00:00:00.000) inserted into the table. SQL Server 2000 implicit data type conversion treats this as integer division. The integer division of 12/13/99 is 0, so the default date and time value is inserted, no error returned. To correct the problem on either version is to wrap the date string with quotes. See Bug #56118 (sqlbug_70) for more details about this situation. Another example of a runtime error is a 605 message. Error: 605 Attempt to fetch logical page %S_PGID in database '%.*ls' belongs to object '%.*ls', not to object '%.*ls'. A 605 error is always a runtime error. However, depending on the transaction isolation level, (e.g. using the NOLOCK lock hint), established by the SPID the handling of the error can vary. Specifically, a 605 error is considered an ACCESS error. Errors associated with buffer and page access are found in the 600 series of errors. When the error is encountered, the isolation level of the SPID is examined to determine proper handling based on information or fatal error level. Transaction Error Checking Not all errors cause transactions to automatically rollback. Although it is difficult to determine exactly which errors will rollback transactions and which errors will not, the main idea here is that programmers must perform error checking and handle errors appropriately. Error Handling Raiserror Details Raiserror seems to be a source of confusion but is really rather simple. Raiserror with severity levels of 20 or higher will terminate the connection. Of course, when the connection is terminated a full rollback of any open transaction will immediately be instantiated by the SQL Server (except distributed transaction with DTC involved). Severity levels lower than 20 will simply result in the error message being returned to the client. They do not affect the transaction scope of the connection. Consider the following batch: use pubs begin tran update authors set au_lname = 'smith' raiserror ('This is bad', 19, 1) with log select @@trancount With severity set at 19, the 'select @@trancount' will be executed after the raiserror statement and will return a value of 1. If severity is changed to 20, then the select statement will not run and the connection is broken. Important Error handling must occur not only in T-SQL batches and stored procedures, but also in application program code. Transactions and Triggers (1 of 2) Basic behavior assumes the implicit transactions setting is set to OFF. This behavior makes it possible to identify business logic errors in a trigger, raise an error, rollback the action, and add an audit table entry. Logically, the insert to the audit table cannot take place before the ROLLBACK action and you would not want to build in the audit table insert into every applications error handler that violated the business rule of the trigger. For more information, see also… SQL Server 2000 Books Online topic “Rollbacks in stored procedure and triggers“ (acdata.chm::/ac_8_md_06_4qcz.htm) IMPLICIT_TRANSACTIONS ON Behavior The behavior of firing other triggers on the same table can be tricky. Say you added a trigger that checks the CODE field. Read only versions of the rows contain the code ‘RO’ and read/write versions use ‘RW.’ Whenever someone tries to delete a row with a code ‘RO’ the trigger issues the rollback and logs an audit table entry. However, you also have a second trigger that is responsible for cascading delete operations. One client could issue the delete without implicit transactions on and only the current trigger would execute and then terminate the batch. However, a second client with implicit transactions on could issue the same delete and the secondary trigger would fire. You end up with a situation in which the cascading delete operations can take place (are committed) but the initial row remains in the table because of the rollback operation. None of the delete operations should be allowed but because the transaction scope was restarted because of the implicit transactions setting, they did. Transactions and Triggers (2 of 2) It is extremely difficult to determine the execution state of a trigger when using explicit rollback statements in combination with implicit transactions. The RETURN statement is not allowed to return a value. The only way I have found to set the @@ERROR is using a ‘raiserror’ as the last execution statement in the last trigger to execute. If you modify the example, this following RAISERROR statement will set @@ERROR to 50000: CREATE TRIGGER trgTest on tblTest for INSERT AS BEGIN ROLLBACK INSERT INTO tblAudit VALUES (1) RAISERROR('This is bad', 14,1) END However, this value does not carry over to a secondary trigger for the same table. If you raise an error at the end of the first trigger and then look at @@ERROR in the secondary trigger the @@ERROR remains 0. Carrying Forward an Active/Open Transaction It is possible to exit from a trigger and carry forward an open transaction by issuing a BEGIN TRAN or by setting implicit transaction on and doing INSERT, UPDATE, or DELETE. Warning It is never recommended that a trigger call BEGIN TRANSACTION. By doing this you increment the transaction count. Invalid code logic, not calling commit transaction, can lead to a situation where the transaction count remains elevated upon exit of the trigger. Transaction Count The behavior is better explained by understanding how the server works. It does not matter whether you are in a transaction, when a modification takes place the transaction count is incremented. So, in the simplest form, during the processing of an insert the transaction count is 1. On completion of the insert, the server will commit (and thus decrement the transaction count). If the commit identifies the transaction count has returned to 0, the actual commit processing is completed. Issuing a commit when the transaction count is greater than 1 simply decrements the nested transaction counter. Thus, when we enter a trigger, the transaction count is 1. At the completion of the trigger, the transaction count will be 0 due to the commit issued at the end of the modification statement (insert). In our example, if the connection was already in a transaction and called the second INSERT, since implicit transaction is ON, the transaction count in the trigger will be 2 as long as the ROLLBACK is not executed. At the end of the insert, the commit is again issued to decrement the transaction reference count to 1. However, the value does not return to 0 so the transaction remains open/active. Subsequent triggers are only fired if the transaction count at the end of the trigger remains greater than or equal to 1. The key to continuation of secondary triggers and the batch is the transaction count at the end of a trigger execution. If the trigger that performs a rollback has done an explicit begin transaction or uses implicit transactions, subsequent triggers and the batch will continue. If the transaction count is not 1 or greater, subsequent triggers and the batch will not execute. Warning Forcing the transaction count after issuing a rollback is dangerous because you can easily loose track of your transaction nesting level. When performing an explicit rollback in a trigger, you should immediately issue a return statement to maintain consistent behavior between a connection with and without implicit transaction settings. This will force the trigger(s) and batch to terminate immediately. One of the methods of dealing with this issue is to run ‘SET IMPLICIT_TRANSACTIONS OFF’ as the first statement of any trigger. Other methods may entails checking @@TRANCOUNT at the end of the trigger and continue to COMMIT the transaction as long as @@TRANCOUNT is greater than 1. Examples The following examples are based on this table: create table tbl50000Insert (iID int NOT NULL) go Note If more than one trigger is used, to guarantee the trigger firing sequence, the sp_settriggerorder command should be used. This command is omitted in these examples to simplify the complexity of the statements. First Example In the first example, the second trigger was never fired and the batch, starting with the insert statement, was aborted. Thus, the print statement was never issued. print('Trigger issues rollback - cancels batch') go create trigger trg50000Insert on tbl50000Insert for INSERT as begin select 'Inserted', * from inserted rollback tran select 'End of trigger', @@TRANCOUNT as 'TRANCOUNT' end go create trigger trg50000Insert2 on tbl50000Insert for INSERT as begin select 'In Trigger2' select 'Trigger 2 Inserted', * from inserted end go insert into tbl50000Insert values(1) print('---------------------- In same batch') select * from tbl50000Insert go -- Cleanup drop trigger trg50000Insert drop trigger trg50000Insert2 go delete from tbl50000Insert Second Example The next example shows that since a new transaction is started, the second trigger will be fired and the print statement in the batch will be executed. Note that the insert is rolled back. print('Trigger issues rollback - increases tran count to continue batch') go create trigger trg50000Insert on tbl50000Insert for INSERT as begin select 'Inserted', * from inserted rollback tran begin tran end go create trigger trg50000Insert2 on tbl50000Insert for INSERT as begin select 'In Trigger2' select 'Trigger 2 Inserted', * from inserted end go insert into tbl50000Insert values(2) print('---------------------- In same batch') select * from tbl50000Insert go -- Cleanup drop trigger trg50000Insert drop trigger trg50000Insert2 go delete from tbl50000Insert Third Example In the third example, the raiserror statement is used to set the @@ERROR value and the BEGIN TRAN statement is used in the trigger to allow the batch to continue to run. print('Trigger issues rollback - uses raiserror to set @@ERROR') go create trigger trg50000Insert on tbl50000Insert for INSERT as begin select 'Inserted', * from inserted rollback tran begin tran -- Increase @@trancount to allow -- batch to continue select @@trancount as ‘Trancount’ raiserror('This is from the trigger', 14,1) end go insert into tbl50000Insert values(3) select @@ERROR as 'ERROR', @@TRANCOUNT as 'Trancount' go -- Cleanup drop trigger trg50000Insert go delete from tbl50000Insert Fourth Example For the fourth example, a second trigger is added to illustrate the fact that @@ERROR value set in the first trigger will not be seen in the second trigger nor will it show up in the batch after the second trigger is fired. print('Trigger issues rollback - uses raiserror to set @@ERROR, not seen in second trigger and cleared in batch') go create trigger trg50000Insert on tbl50000Insert for INSERT as begin select 'Inserted', * from inserted rollback begin tran -- Increase @@trancount to -- allow batch to continue select @@TRANCOUNT as 'Trancount' raiserror('This is from the trigger', 14,1) end go create trigger trg50000Insert2 on tbl50000Insert for INSERT as begin select @@ERROR as 'ERROR', @@TRANCOUNT as 'Trancount' end go insert into tbl50000Insert values(4) select @@ERROR as 'ERROR', @@TRANCOUNT as 'Trancount' go -- Cleanup drop trigger trg50000Insert drop trigger trg50000Insert2 go delete from tbl50000Insert Lesson 3: Concepts – Locks and Applications This lesson outlines some of the common causes that contribute to the perception of a slow server. What You Will Learn After completing this lesson, you will be able to:  Explain how lock hints are used and their impact.  Discuss the effect on locking when an application uses Microsoft Transaction Server.  Identify the different kinds of deadlocks including distributed deadlock. Recommended Reading  Charter 14 “Locking”, Inside SQL Server 2000 by Kalen Delaney  Charter 16 “Query Tuning”, Inside SQL Server 2000 by Kalen Delaney Q239753 – Deadlock Situation Not Detected by SQL Server Q288752 – Blocked SPID Not Participating in Deadlock May Incorrectly be Chosen as victim Locking Hints UPDLOCK If update locks are used instead of shared locks while reading a table, the locks are held until the end of the statement or transaction. UPDLOCK has the advantage of allowing you to read data (without blocking other readers) and update it later with the assurance that the data has not changed since you last read it. READPAST READPAST is an optimizer hint for use with SELECT statements. When this hint is used, SQL Server will read past locked rows. For example, assume table T1 contains a single integer column with the values of 1, 2, 3, 4, and 5. If transaction A changes the value of 3 to 8 but has not yet committed, a SELECT * FROM T1 (READPAST) yields values 1, 2, 4, 5. Tip READPAST only applies to transactions operating at READ COMMITTED isolation and only reads past row-level locks. This lock hint can be used to implement a work queue on a SQL Server table. For example, assume there are many external work requests being thrown into a table and they should be serviced in approximate insertion order but they do not have to be completely FIFO. If you have 4 worker threads consuming work items from the queue they could each pick up a record using read past locking and then delete the entry from the queue and commit when they're done. If they fail, they could rollback, leaving the entry on the queue for the next worker thread to pick up. Caution The READPAST hint is not compatible with HOLDLOCK.  Try This: Using Locking Hints 1. Open a Query Window and connect to the pubs database. 2. Execute the following statements (--Conn 1 is optional to help you keep track of each connection): BEGIN TRANSACTION -- Conn 1 UPDATE titles SET price = price * 0.9 WHERE title_id = 'BU1032' 3. Open a second connection and execute the following statements: SELECT @@lock_timeout -- Conn 2 GO SELECT * FROM titles SELECT * FROM authors 4. Open a third connection and execute the following statements: SET LOCK_TIMEOUT 0 -- Conn 3 SELECT * FROM titles SELECT * FROM authors 5. Open a fourth connection and execute the following statement: SELECT * FROM titles (READPAST) -- Conn 4 WHERE title_ID < 'C' SELECT * FROM authors How many records were returned? 3 6. Open a fifth connection and execute the following statement: SELECT * FROM titles (NOLOCK) -- Conn 5 WHERE title_ID 0 the lock manager also checks for deadlocks every time a SPID gets blocked. So a single deadlock will trigger 20 seconds of more immediate deadlock detection, but if no additional deadlocks occur in that 20 seconds, the lock manager no longer checks for deadlocks at each block and detection again only happens every 5 seconds. Although normally not needed, you may use trace flag -T1205 to trace the deadlock detection process. Note Please note the distinction between application lock and other locks’ deadlock detection. For application lock, we do not rollback the transaction of the deadlock victim but simply return a -3 to sp_getapplock, which the application needs to handle itself. Deadlock Resolution How is a deadlock resolved? SQL Server picks one of the connections as a deadlock victim. The victim is chosen based on either which is the least expensive transaction (calculated using the number and size of the log records) to roll back or in which process “SET DEADLOCK_PRIORITY LOW” is specified. The victim’s transaction is rolled back, held locks are released, and SQL Server sends error 1205 to the victim’s client application to notify it that it was chosen as a victim. The other process can then obtain access to the resource it was waiting on and continue. Error 1205: Your transaction (process ID #%d) was deadlocked with another process and has been chosen as the deadlock victim. Rerun your transaction. Symptoms of deadlocking Error 1205 usually is not written to the SQL Server errorlog. Unfortunately, you cannot use sp_altermessage to cause 1205 to be written to the errorlog. If the client application does not capture and display error 1205, some of the symptoms of deadlock occurring are:  Clients complain of mysteriously canceled queries when using certain features of an application.  May be accompanied by excessive blocking. Lock contention increases the chances that a deadlock will occur. Triggers and Deadlock Triggers promote the deadlock priority of the SPID for the life of the trigger execution when the DEADLOCK PRIORITY is not set to low. When a statement in a trigger causes a deadlock to occur, the SPID executing the trigger is given preferential treatment and will not become the victim. Warning Bug 235794 is filed against SQL Server 2000 where a blocked SPID that is not a participant of a deadlock may incorrectly be chosen as a deadlock victim if the SPID is blocked by one of the deadlock participants and the SPID has the least amount of transaction logging. See KB article Q288752: “Blocked Spid Not Participating in Deadlock May Incorrectly be Chosen as victim” for more information. Distributed Deadlock – Scenario 1 Distributed Deadlocks The term distributed deadlock is ambiguous. There are many types of distributed deadlocks. Scenario 1 Client application opens connection A, begins a transaction, acquires some locks, opens connection B, connection B gets blocked by A but the application is designed to not commit A’s transaction until B completes. Note SQL Server has no way of knowing that connection A is somehow dependent on B – they are two distinct connections with two distinct transactions. This situation is discussed in scenario #4 in “Q224453 INF: Understanding and Resolving SQL Server 7.0 Blocking Problems”. Distributed Deadlock – Scenario 2 Scenario 2 Distributed deadlock involving bound connections. Two connections can be bound into a single transaction context with sp_getbindtoken/sp_bindsession or via DTC. Spid 60 enlists in a transaction with spid 61. A third spid 62 is blocked by spid 60, but spid 61 is blocked by spid 62. Because they are doing work in the same transaction, spid 60 cannot commit until spid 61 finishes his work, but spid 61 is blocked by 62 who is blocked by 60. This scenario is described in article “Q239753 - Deadlock Situation Not Detected by SQL Server.” Note SQL Server 6.5 and 7.0 do not detect this deadlock. The SQL Server 2000 deadlock detection algorithm has been enhanced to detect this type of distributed deadlock. The diagram in the slide illustrates this situation. Resources locked by a spid are below that spid (in a box). Arrows indicate blocking and are drawn from the blocked spid to the resource that the spid requires. A circle represents a transaction; spids in the same transaction are shown in the same circle. Distributed Deadlock – Scenario 3 Scenario 3 Distributed deadlock involving linked servers or server-to-server RPC. Spid 60 on Server 1 executes a stored procedure on Server 2 via linked server. This stored procedure does a loopback linked server query against a table on Server 1, and this connection is blocked by a lock held by Spid 60. Note No version of SQL Server is currently designed to detect this distributed deadlock. Lesson 4: Information Collection and Analysis This lesson outlines some of the common causes that contribute to the perception of a slow server. What You Will Learn After completing this lesson, you will be able to:  Identify specific information needed for troubleshooting issues.  Locate and collect information needed for troubleshooting issues.  Analyze output of DBCC Inputbuffer, DBCC PSS, and DBCC Page commands.  Review information collected from master.dbo.sysprocesses table.  Review information collected from master.dbo.syslockinfo table.  Review output of sp_who, sp_who2, sp_lock.  Analyze Profiler log for query usage pattern.  Review output of trace flags to help troubleshoot deadlocks. Recommended Reading Q244455 - INF: Definition of Sysprocesses Waittype and Lastwaittype Fields Q244456 - INF: Description of DBCC PSS Command for SQL Server 7.0 Q271509 - INF: How to Monitor SQL Server 2000 Blocking Q251004 - How to Monitor SQL Server 7.0 Blocking Q224453 - Understanding and Resolving SQL Server 7.0 Blocking Problem Q282749 – BUG: Deadlock information reported with SQL Server 2000 Profiler Locking and Blocking  Try This: Examine Blocked Processes 1. Open a Query Window and connect to the pubs database. Execute the following statements: BEGIN TRAN -- connection 1 UPDATE titles SET price = price + 1 2. Open another connection and execute the following statement: SELECT * FROM titles-- connection 2 3. Open a third connection and execute sp_who; note the process id (spid) of the blocked process. (Connection 3) 4. In the same connection, execute the following: SELECT spid, cmd, waittype FROM master..sysprocesses WHERE waittype 0 -- connection 3 5. Do not close any of the connections! What was the wait type of the blocked process?  Try This: Look at locks held Assumes all your connections are still open from the previous exercise. • Execute sp_lock -- Connection 3 What locks is the process from the previous example holding? Make sure you run ROLLBACK TRAN in Connection 1 to clean up your transaction. Collecting Information See Module 2 for more about how to gather this information using various tools. Recognizing Blocking Problems How to Recognize Blocking Problems  Users complain about poor performance at a certain time of day, or after a certain number of users connect.  SELECT * FROM sysprocesses or sp_who2 shows non-zero values in the blocked or BlkBy column.  More severe blocking incidents will have long blocking chains or large sysprocesses.waittime values for blocked spids.  Possibl
EurekaLog 7.5 (18-August-2016) 1)..Important: Installation layout was changed. All packages now have version suffix (e.g. EurekaLogCore240.bpl). No files are copied to \bin folder of IDE. Run-time package (EurekaLogCore) is copied to Windows\System32 folder. Refer to help for more info. 2)....Added: RAD Studio 10.1 Berlin support 3)....Added: IDE F1 help integration (on CHM-based IDEs only, i.e. XE8+) 4)....Added "--el_injectjcl", "--el_createjcl", and "--el_createdbg" command-line options for ecc32/emake to inject JEDI/JCL debug info, create .jdbg file, and create .dbg file (Microsoft debug format). Later is supported when map2dbg.exe tool is placed in \Bin folder of EurekaLog installation (separate download is required) 5)....Added: Exception2HRESULT in EAppDLL to simplify developing DLLs with "DLL" profile 6)....Added: Use ShellExecute option for mailto send method 7)....Added: "Mandatory e-mail only when sending" option 8)....Added: Exception line highlighting in disassember view in EurekaLog exception dialog and Viewer 9)....Added: Detection/logging Delphi objects in disassembly view 10)..Added: Support for multi-monitor info 11)..Added: Support for detection of Windows 10 updates 12)..Added: OS edition detection 13)..Added: "User" and "Session" columns to processes list, processes list is also sorted by session first 14)..Added: Support for showing current user processes only 15)..Added: Expanding environment variables for "Support URL" 16)..Fixed: Range-check error on systems with MBCS ACP 17)..Fixed: 64-bit shared memory manager may not work 18)..Fixed: Possible "Unit XYZ was compiled with a different version of ABC" when using packages 19)..Fixed: FastMM shared MM compatibility 20)..Fixed: Minor bugs in stack tracing (which usually affected stacks for leaks) 21)..Fixed: Rare deadlocks in multi-threaded applications 22)..Fixed: Taking screenshot of minimized window 23)..Fixed: NT service may not log all exceptions 24)..Fixed: SSL port number for Bugzilla 25)..Fixed: Disabling "Activate Exception Filters" option was ignored 26)..Fixed: Missing FTP proxy settings 27)..Fixed: IntraWeb support is updated up to 14.0.64 28)..Fixed: Retrieving some process paths in processes list 29)..Fixed: CPU view rendering in EurekaLog exception dialog and Viewer 30)..Fixed: Some issues in naming threads 31)..Fixed: Removed exported helper _462EE689226340EAA982C5E8307B3F9E function (replaced with mapped file) 32)..Changed: Descriptions of EurekaLog project options now list corresponding property names of TEurekaModuleOptions class. 33)..Changed: Default template of HTML/web dialog now includes call stack by default 34)..Changed: EurekaLog 7 now can be installed over EurekaLog 6 automatically, with no additional actions/tools EurekaLog 7.4 (7.4.0.0), 26-January-2016 1)....Fixed: Performance issue in DLL exports debug information provider 2)....Fixed: Range-check error in Send dialog 3)....Fixed: Possible FPU control word unexpected change 4)....Fixed: JIRA sending to project with no version info 5)....Fixed: Viewer sorting affected by local region settings 6)....Fixed: Exception filters ignore settings for restart/terminate EurekaLog 7.3 Hotfix 2 (7.3.2.0), 20-October-2015 1)....Fixed: Added workaround for codegen bug in Delphi 7 (possibly - other), bug manifests itself as wrong date-time in reports or integer overflows 2)....Fixed: Some MAPI DLLs may not be loaded correctly 3)....Fixed: Handling SEC_I_INCOMPLETE_CREDENTIALS in SSPI code (added searching client certificate) 4)....Fixed: Range-check error when closing WinAPI dialog EurekaLog 7.3 Hotfix 1 (7.3.1.0), 2-October-2015 1)....Fixed: Long startup time on terminal services servers EurekaLog 7.3 (7.3.0.0), 24-September-2015 1)....Added: RAD Studio 10 Seattle support 2)....Added: Performance counters for run-time (internal logging with --el_debug) 3)....Fixed: spawned by ecc32/emake processes now start with the same priority 4)....Fixed: ThreadID = 0 in StandardEurekaNotify 5)....Fixed: Dialog auto-close timer may reset without user input 6)....Fixed: Possible hang when quickly loading/unloading EurekaLog-enabled DLL 7)....Fixed: Possible hang in COM DLLs 8)....Fixed: Removed some unnecessary file system access on startup 9)....Fixed: Possible wrong font size in EurekaLog tools 10)..Fixed: Ignore timeouts from Shell_NotifyIcon 11)..Fixed: Possible failure to handle/process stack overflow exceptions 12)..Changed: VCL/CLX/FMX now will assign Application.OnException handler when low-level hooks are disabled EurekaLog 7.2 Hotfix 6 (7.2.6.0), 14-July-2015 1)....Added: csoCaptureDelphiExceptions option 2)....Fixed: Handling of SECBUFFER_EXTRA in SSPI code 3)....Fixed: Several crashes in sending code for very old Delphi versions 4)....Fixed: Regression (from hotfix 5) crash in some IDEs EurekaLog 7.2 Hotfix 5 (7.2.5.0), 1-July-2015 1)....Added: HKCU\Software\EurekaLab\Viewer\4.0\UI\Statuses registry key to allow status customizations in Viewer 2)....Added: "Disable hang detection under debugger" option 3)....Fixed: Wrong button caption in standalone "Steps to reproduce" dialog 4)....Fixed: Wrong passing of Boolean parameters in JSON (affects JIRA) 5)....Fixed: Wrong sorting of BugID, Count and DateTime columns in Viewer 6)....Fixed: Empty "Count" field/column is now displayed as "1" in Viewer 7)....Fixed: Generic names with "," could not be decoded in Viewer 8)....Fixed: Updated Windows 10 detection for latest builds of Windows 10 9)....Fixed: Sleep and hybernation no longer trigger false-positive "application freeze" 10)..Fixed: Wrong function codes for hooking (affects ISAPI application type) 11)..Fixed: Wrong button caption in "Steps to Reproduce" dialog 12)..Fixed: Crash when taking snapshot of some proccesses by Threads Snapshot tool 13)..Fixed: Minor improvements in leak detection EurekaLog 7.2 Hotfix 4 (7.2.4.0), 10-June-2015 1)....Added "ECC32TradeSpeedForMemory" option - defaults to 0/False, could be changed to 1 via Custom/Manual tab. This option will switch from fast-methods to slower methods, but which take less memory. Use 0 (default) for small projects, use 1 for large projects (if ecc32 runs out of memory). 2)....Added: --el_DisableDebuggerPresent command-line option for compatibility with 3rd party debuggers (AQTime, etc.) 3)....Added: AQTime auto-detect 4)....Fixed: Performance optimizations 5)....Fixed: Windows 8+ App Menu shortcuts 6)....Fixed: Unmangling on x64 EurekaLog 7.2 Hotfix 3 (7.2.3.0), 20-May-2015 1)....Added: Support for token auth in Bugzilla (latest 4.x builds) 2)....Added: Support for API key auth in Bugzilla (5.x) 3)....Added: Support for /EL_DisableMemoryFilter command-line option 4)....Added: Asking e-mail when user switches to "details" from MS Classic without entering e-mail 5)....Fixed: Compatibility issues with older Bugzilla versions (3.x) 6)....Fixed: Passing settings between dialogs 7)....Fixed: "Ask for steps to reproduce" dialog is now DPI-aware 8)....Fixed: Silently ignore and fix invalid values in project options EurekaLog 7.2 Hotfix 2 (7.2.2.0), 30-April-2015 1)....Fixed: Confusing message in Manage tool when using with Trial/Pro 2)....Fixed: Range check error in processes information for x64 machines (affects startup of any EurekaLog-enabled module) 3)....Fixed: Auto-detect personality by project extension if --el_mode switch is missing 4)....Fixed: More details for diagnostic sending 5)....Fixed: Wrong settings for MAP files in C++ Builder 6)....Fixed: Wrong code page was used to decode ANSI bug reports 7)....Fixed: Attaching .PAS files instead of .OBJ in C++ Builder 2006+ Pro/Trial EurekaLog 7.2 Hotfix 1 (7.2.1.0), 3-April-2015 1)....Fixed: Wrong float-str convertion when ThousandSeparator is '.' EurekaLog 7.2 (7.2.0.0), 1-April-2015 1)....Important: TEurekaLogV7 component was renamed to TEurekaLogEvents. Please, update your projects by renaming or recreating the component 2)....Important: File layout was changed for BDS 2006+. Delphi and C++ Builder files are now located in StudioNum folders instead of old DelphiNum and CBuilderNum folders. Update your search paths if needed 3)....Added: Major improvements in DumpAllocationsToFile function (EMemLeaks unit) 4)....Added: MemLeaksSetParentBlock, MemLeaksOwn, EurekaTryGetMem functions (EMemLeaks unit) 5)....Added: Improvements for call stack of dynarrays/strings allocations (leaks) 6)....Added: "Elem size" when reporting leaks in dynarrays 7)....Added: Streaming unpacked debug info into temporal files instead of memory - this greatly reduces run-time application memory usage at cost of slightly slower exception processing. This also reduces memory footprint for ecc32/emake 8)....Added: Showing call stacks for 2 new types of fatal memory errors 9)....Added: EMemLeaks._ReserveOutOfMemory to control reserve size of out of memory errors (default is 50 Mb) 10)..Added: "MinLeaksLimitObjs" option (EMemLeaks unit) 11)..Added: Fatal memory problem now pauses all threads in application 12)..Added: Fatal memory problem now change thread name (to simplify debugging) 13)..Added: boPauseELThreads and boDoNotPauseELServiceThread options (currently not visible in UI) 14)..Added: Support for texts collections out of default path 15)..Added: Support for relative file paths to text collections and external settings 16)..Added: Support for environment variables in project option's paths 17)..Added: Support for relative file paths and environment variables for events and various module paths 18)..Added: Logging in Manage tool 19)..Added: Windows 10 version detection 20)..Added: Stack overflow tracing 21)..Added: Major improvements in removal of recursive areas from call stack 22)..Added: Statistics collection 23)..Added: Support for uploading multiple files in JIRA 24)..Added: EResLeaks improvements (new funcs: ResourceAdd, ResourceDelete, ResourceName; support for realloc-like functions) 25)..Fixed: Added workaround for bug in JIRA 5.x 26)..Fixed: Rare EurekaLog internal error 27)..Fixed: Ignored unhandled thread exceptions (when EurekaLog is disabled) now triggers default OS processing (WER) 28)..Fixed: Irnored exceptions (via per-exception/events) now bring up default RTL handler 29)..Fixed: Format error in Viewer 30)..Fixed: Leak of EurekaLog exception information object 31)..Fixed: Wrong chaining exceptions inside GetMem/FreeMem 32)..Fixed: Memory leak after low-level unhook of function 33)..Fixed: Re-parenting after ReallocMem 34)..Fixed: Editing SMTP server options 35)..Fixed: SMTP server not using real user e-mail in FROM field 36)..Fixed: Some multi-threading crashes 37)..Fixed: Fixed crashes in Manage tool 38)..Fixed: Range-check error in Viewer 39)..Fixed: EurekaLog error dialog appearing under other windows 40)..Fixed: AV when parsing TDS (emake/C++ Builder specific) 41)..Fixed: Unable to build call stacks for other threads due to insufficient rights 42)..Fixed: Version checks for BugZilla and JIRA 43)..Fixed: Not catching out-of-module AVs when "Capture exceptions only from current module" option is checked 44)..Fixed: Checking for remaining exceptions at shutdown (C++ Builder specific, AcquireExceptionObject returns wrong info) 45)..Fixed: "get call stack of ... threads" / "suspend ... threads" options (avoid rare multithreading race conditions) 46)..Fixed: Crash when naming thread without EurekaLog thread info 47)..Fixed: Detection of immediate caller for memory funcs 48)..Fixed: Non-working Assign for options 49)..Fixed: Handling of explicitly chained exceptions 50)..Fixed: Various exception/threading fixes for MS debug provider 51)..Fixed: Processing hardware unhandled exceptions (QC #55007) 52)..Fixed: Unchecking dialog options when export/import 53)..Fixed: BSTR leak 54)..Fixed: JIRA decimal separator bug 55)..Changed: Now unhandled exceptions will be handled by EurekaLog even if EurekaLog is disabled in the thread - only global EurekaLog-enabled status is respected 56)..Changed: Viewer version now matches version of EurekaLog 57)..Changed: DeleteServiceFilesOption now always False by default 58)..Changed: Speed improvements for known memory leaks (reserved leaks) 59)..Changed: Improved logging for sending 60)..Changed: Switching to detailed mode without entering (mandatory) e-mail: now EL will not block this 61)..Changed: .ToString for exception info now uses compact stack formatter 62)..Removed: Custom field editor (replaced it with link to "Custom" page) 63)..Removed: EurekaLog 7 no longer could be installed over EurekaLog 6. Manage tool from EurekaLog 7 will no longer work with EurekaLog 6. EurekaLog 7.1 update 1 (7.1.1.0), 19-October-2014 1)....Added: "Send in separated thread" option 2)....Added: Hang detection will now use Wait Chain Traversal (WCT) on Vista+ systems to detect deadlocks in any EurekaLog-enabled threads 3)....Added: OS install language and UI language fields in bug report 4)....Fixed: Viewer is not able to decrypt reports with generics 5)....Fixed: EVariantTypeCastError in Viewer when changing status of some bug reports 6)....Fixed: EcxInvalidDataControllerOperation in Viewer 7)....Fixed: Stack overflow at run-time for certain combination of project options 8)....Fixed: BMP re-draw bug in UI dialogs 9)....Fixed: Rogue "corrupted" error message for valid ZIPs of certain structure 10)..Fixed: Various range check errors in Viewer 11)..Fixed: Possible encoding errors for non-ASCII reports in Viewer on certain environments 12)..Fixed: Wrong count in Viewer when importing reports without proper "count" field 13)..Fixed: Duplicate reports may appear in bug report file when "Do not save duplicate errors" option is checked 14)..Fixed: False-positive detection of some virtual machines 15)..Fixed: Processing of exceptions from message handlers during message pumping cycle inside exception dialogs 16)..Fixed: Access Violation if exception dialog was terminated by exception 17)..Fixed: Hardware exceptions from unit's initialization/finalization may be unprocessed 18)..Changed: "VIEW" action for Viewer now will open ALL bug reports inside bug report file; reports will not be merged by BugID. "IMPORT" action remains the same: duplicate reports are merged, "count" is increased 19)..Changed: Charset field in bug report now shows both charset and code page EurekaLog 7.1 (7.1.0.00), 23-September-2014 1)....Added: XE7 support 2)....Added: XE6 support 3)....Added: New DLL demo 4)....Added: Custom profiles are now shown in "Application type" combo-box 5)....Added: Non-empty "steps to reproduce" will be added to existing bug tracker issues with empty "steps to reproduce" 6)....Added: Support for custom fields in FogBugz (API version 8 and above) 7)....Added: Support for unsequenced line numbers in PDB/DBG files (--el_source switch) 8)....Fixed: XML bug report were generated wrong 9)....Fixed: Strip relocations code for Win64 10)..Fixed: EurekaLog conditional symbols removed improperly when deactivating EurekaLog 11)..Fixed: Sending reports to non-default port numbers (affects web-based methods) 12)..Fixed: SSL validation check may reject valid SSL certificate (SMTP Client/Server) 13)..Fixed: SSL errors may be not reported 14)..Fixed: Viewer did not consider empty bug reports as corrupted 15)..Fixed: "DLL" profile now can be used with packages properly 16)..Fixed: Few rare memory leaks 17)..Fixed: Possible deadlock when using MS debug info provider 18)..Fixed: C++ Builder project files was saved incorrectly (RAD Studio 2007+) 19)..Fixed: "Show restart checkbox after N errors" counts handled exceptions 20)..Fixed: IDE expert's DPR parser (added support for multi-part idents) 21)..Fixed: Rare access violation in hook code 22)..Fixed: Thread handle leaks (added _NotifyThreadGone/_CleanupFinishedThreads functions to be called manually - only when low-level hooks are not installed) 23)..Fixed: EurekaLog's installer hang 24)..Fixed: Bug in object/class validation 25)..Fixed: Bug when using TThreadEx without EurekaLog 26)..Fixed: Leaks detection may not work with certain combination of options 27)..Fixed: Deadlock in some cases when using EurekaLog threading option set to "enabled in RTL threads, disabled in Windows threads". 28)..Changed: TEurekaExceptionInfo.CallStack will be nil until exception is actually raised 29)..Changed: FogBugz and BugZilla: changed bugs identification within project (to allow two bugs exists with same BugID in different projects) 30)..Changed: Blocked manual creation/destruction of ExceptionManager class and EurekaExceptionInfo 31)..Changed: ECC32/EMAKE runs from IDE without changing priority, added ECC32PriorityClass option 32)..Improved: Minor help and text improvements EurekaLog 7.0.07 Hotfix 2 (7.0.7.2), 11-December-2013 1)....Fixed: Delphi compiler code generation bug (Delphi 2007 and below) 2)....Fixed: Code hooks may rarely be set incorrectly (code stub relocation fails) 3)....Fixed: Win64 call stacks functions now work more similar to 32 bit call stacks EurekaLog 7.0.07 Hotfix 1 (7.0.7.1), 2-December-2013 1)....Added: Alternative caption for e-mail input control when e-mail is mandatory 2)....Fixed: Rare range check error in WinAPI visual dialogs 3)....Fixed: Wrong error detection for OnExceptionError event 4)....Fixed: Wrong TResponce processing 5)....Fixed: Problems with encrypted call stack decoding 6)....Fixed: OnPasswordRequest event may have no effect EurekaLog 7.0.07 (7.0.7.0), 25-November-2013 1)....Added: Ability to use Assign between call stack and TStrings 2)....Added: 64-bit disassembler 3)....Added: Support for variables and relative file paths in "Additional Files" send option 4)....Added: --el_source switch for ecc32/emake compilers 5)....Added: support for post-processing non-Embarcadero executables 6)....Added: EOTL.pas unit for better OmniThreadLibrary integration 7)....Added: RAD Studio XE5 support 8)....Added: New "Capture call stacks of EurekaLog-enabled threads" option 9)....Added: "Deferred call stacks" option for 64-bit 10)..Added: Copy report to clipboard now copies both report text and report file 11)..Added: "AttachBothXMLAndELReports" option to include both .elx and .el files into bug report 12)..Added: EMemLeaks.MemLeaksErrorsToIgnore option to exclude certain memory errors from being considered as fatal 13)..Added: Call stack with any encrypted entry will be fully encrypted now 14)..Added: Option to exclude certain memory errors from being considered as fatal (EMemLeaks.MemLeaksErrorsToIgnore) 15)..Added: New "HTTP Error Code" option for all web-based dialogs (CGI, ISAPI, etc.) 16)..Added: Support for Unicode in Simple MAPI send method (requires Windows 8 or latest Microsoft Office) 17)..Added: New value for call stack detalization option (show any addresses, including those not belonging to any executable module) 18)..Fixed: Wrong JSON escaping for strings (affects JIRA send method) 19)..Fixed: Range-check error in Viewer when viewing bug reports with high addresses 20)..Fixed: Selecting Win32 service application type is no longer resets to custom/unsupported 21)..Fixed: Possible hang when testing dialogs from EurekaLog project options dialog 22)..Fixed: Rare resetting of some options when saving .eof file 23)..Fixed: Exception pointer could be removed from call stack due to debug details filtering 24)..Fixed: Rare case when LastThreadException returned nil while there was active thread exception 25)..Fixed: Rare case when ShowLastThreadException do nothing 26)..Fixed: Improved compatibility for OmniThreadLibrary and AsyncCalls 27)..Fixed: Included fix for QC #72147 28)..Fixed: 64-bit MS Debug Info Provider (please, re-setup cache options using configuration dialog) 29)..Fixed: "Deferred call stacks" option failed to capture call stack when exception is re-raised between threads 30)..Fixed: "Deferred call stacks" option may produce cutted call stack in rare cases 31)..Fixed: Several minor call stacks improvements and optimizations 32)..Fixed: Several 64-bit Pointer Integer convertion issues 33)..Fixed: Multi-threading deadlock issue 34)..Fixed: Black screenshots in 64 bit applications 35)..Fixed: Copying to clipboard hot-key was registered globally 36)..Fixed: Shell (mailto) send method may fail (64 bit) 37)..Fixed: Possible wrong file paths for attaches in (S)MAPI send methods 38)..Fixed: Environment variables were not expanded in MAPI send method 39)..Fixed: (non-Unicode IDE) EurekaLog is not activated when application started from folder with Unicode characters 40)..Fixed: Encrypted call stacks may be encrypted partially by EurekaLog Viewer in rare cases 41)..Fixed: Crash when sending leak report with visual progress dialog (only some IDEs are affected) 42)..Fixed: ecc32/emake could not see external configuration file with the same name as project (e.g. Project1.eof for Project1.dpr) 43)..Fixed: Added missed RTL implementation for ExternalProps in Delphi 6 (affects Mantis sending) 44)..Fixed: IDE crash when switching to threads window 45)..Changed: Removed temporal solution which was used before option to defer call stack creation was introduced 46)..Changed: "Default EurekaLog state in new threads" option is changed from Boolean flag into enum. You need to re-setup this option 47)..Changed: Disable EurekaLog for thread when creating call stack or handle exception - this increases stability and performance 48)..Changed: LastException property is remove from exception manager as not thread safe. Use LastThreadException property instead 49)..Changed: Lock/Unlock from thread manager and exception manager are removed to avoid deadlocks 50)..Changed: ThreadsSnapshot tool now tries to capture call stack without injecting DLL 51)..Changed: Build events now runs with CREATE_NO_WINDOW flag (console window is hidden) 52)..Improved: More articles in help EurekaLog 7.0.06 (7.0.6.0), 1-June-2013 1)....Added: Experimental 64 bit C++ Builder support 2)....Added: New tab in EurekaLog project options: "External tools" 3)....Added: Option to catch all IDE errors (to debug your own IDE packages) 4)....Added: Option to catch only exceptions from current module 5)....Added: Option to defer building call stack 6)....Added: RAD Studio XE4 support 7)....Added: Support for AppWave 8)....Fixed: Fixed event handlers declarations for the EurekaLog component 9)....Fixed: Infinite recursive calls when using ToString from EndReport event handler 10)..Fixed: UPX compatibility issue 11)..Fixed: Range check errors for system error codes 12)..Fixed: Rare IDE stack overflow 13)..Fixed: JIRA unit was not added automatically 14)..Fixed: EurekaLog no longer tries to check for leaks when memory manager filter is disabled 15)..Fixed: Possible deadlock on shutdown with freeze checks active 16)..Fixed: Issues with settings dialog and Win32 Service application type 17)..Fixed: ThreadSnapshot tool was not able to take snapshots of Win64 processes 18)..Fixed: WCT is disabled for leaks 19)..Fixed: TContext declarations for Win64 20)..Fixed: Check for updates now correctly sets time of last check 21)..Fixed: (Win64) Several Pointer Integer convertion errors 22)..Fixed: Internal error when exception info object was deleted while it was still used by SysUtils exception object 23)..Fixed: Semeral problems with "EurekaLog look & feel" style for EurekaLog error dialog 24)..Fixed: Using text collection resets exception filters 25)..Fixed: Rare access violation if registering event handlers is placed too early 26)..Fixed: SMTP RFC date formatting 27)..Fixed: Rare empty call stack bug 28)..Fixed: Hang detection was not working if EurekaLog was disabled in threads 29)..Fixed: AV for double-free TEncoding 30)..Changed: ecc32/emake no longer alters arguments for dcc32/make unless new options --el_add_default_options is specified 31)..Changed: Save/load options methods was moved to TEurekaModuleOptions class 32)..Changed: Saving options to EOF file now adds hidden options and removes obsolete options (only when compatibility mode is off) 33)..Changed: Compiling installed packages now silently ignores EurekaLog instead of showing "File is in use" error message 34)..Improved: More readable disk/memory sizes in bug reports 35)..Improved: More descriptive settings dialog when using external configuration 36)..Improved: ThreadSnapshot tool now aquired DEBUG priviledge for taking snapshot. This allows it to bypass security access checks when opening target process. 37)..Improved: Changed BugID default generation to include error code for OS errors and error message for DB errors 38)..Improved: Mantis API (WSDL) was updated to the latest version (1.2.14) 39)..Improved: IntraWeb compatibility (old and new versions) 40)..Improved: COM applications compatibility 41)..Improved: Build events now accept shell commands 42)..Improved: More articles in help EurekaLog 7.0.05 (7.0.5.0), 7-February-2013 1)....Added: JIRA support 2)....Added: Virtual machine detection (new field in bug reports) 3)....Fixed: "Use Main Module options" option was loading empty options for some cases 4)....Fixed: Wrong record declarations for Simple MAPI on Win64 5)....Fixed: Performance issues with batch module options updating 6)....Fixed: Wrong leaks report with both MemLeaks/ResLeaks options active 7)....Fixed: Wrong info for nested exceptions in some cases 8)....Fixed: AV under debugger for Win64 (added support for _TExitDllException) 9)....Fixed: Wrong record declarations for process/thread info on Win64 10)..Fixed: Support for FinalBuilder on XE2/XE3 with spaces in file paths 11)..Fixed: Rare double-free of module information (ModuleInfoList) 12)..Fixed: Rare External Exception C000071C on shutdown (only under debuggger) 13)..Fixed: Added large addresses support in Viewer 14)..Fixed: Counter options in memory leaks category is now working properly 15)..Fixed: Rare range-check error in TEurekaModulesList.AddModuleFromFileName 16)..Fixed: FTP force directories dead lock 17)..Fixed: Fixed wrong index being used when clearing compatibility mode (EurekaLog project options dialog) 18)..Fixed: Default thread state do not affect main thread now 19)..Fixed: Sometimes wrong thread may be used when altering EurekaLog active state for external thread 20)..Fixed: Wrong DNS lookup on ANSI 21)..Fixed: Problems with IDE expert and projects on network paths 22)..Fixed: Added support for arguments in URLs (HTTP sending) 23)..Fixed: Possible deadlock in multithreaded applications 24)..Fixed: Problems with unicode characters in project files on non-Unicode IDEs 25)..Fixed: Infinite recursive calls when using ToString from EndReport event handler 26)..Fixed: Win64 GetCaller now returns pointer to call instruction, not return address 27)..Improved: Standalone Editor do not force save/load folder by default 28)..Improved: DLL profile now can use additional application type hooks automatically 29)..Improved: EurekaLog now able to work with read-only projects (see help for more info) EurekaLog 7.0.04 (7.0.4.0), 2-December-2012 1)....Added: Support for nested exceptions in DLLs 2)....Fixed: Options bug in EurekaLogSendEmail function 3)....Fixed: Weird behaviour for steps to reproduce and custom fields 4)....Fixed: Installation for single personality (BDS) 5)....Fixed: Range check error in EModules 6)....Fixed: Bug in exception destroy hook 7)....Fixed: OnExceptionNotify event is no longer called for handled exceptions without option checked 8)....Fixed: DEP checks on startup no longer cause exception 9)....Fixed: Invalid declaration for MS Debug API 10)..Fixed: OLE mode change error for "Test" send button 11)..Fixed: Fixes for multiply loading of the same DLL 12)..Fixed: Removed PNG compression from icons (tools) 13)..Fixed: Range-check error in dialogs with EurekaLog style enabled 14)..Fixed: Send progress dialog may keep busy forever processing window messages (message flood from rapid application GUI updates) 15)..Fixed: Thread pausing options now work correctly 16)..Improved: New features in exception filters - marking exceptions as "expected", filtering by properties (RTTI) 17)..Improved: Recovery from memory errors without debugging memory manager 18)..Improved: Viewer's password edit now hides password with asterisks 19)..Updated: Changed names of .inc files to avoid name conflicts with other libraries 20)..Updated: Help EurekaLog 7.0.03 (7.0.3.0), 6-October-2012 1)....Fixed: Removed some consts keywords for event handlers, so now C++ Builder can alter arguments (this change may require you to adjust your custom code) 2)....Fixed: Fallback code for false-positive results on memory probing 3)....Fixed: Range check errors in SSL/TLS implementation 4)....Fixed: "EurekaLog is not active" error message during send testing 5)....Fixed: Incorrect memory probing when DEP is off (old systems) 6)....Fixed: Installation of 64-bit BPLs 7)....Fixed: Dialog preview 8)....Fixed: Win64 fixes for XE3 9)....Fixed: Support for project groups (mixed project types) 10)..Fixed: Windows 2000 hooks compatibility 11)..Fixed: mailto double quotes escaping 12)..Fixed: Simple MAPI WOW compatibility 13)..Fixed: Simple MAPI modal issues 14)..Fixed: Various range check errors 15)..Changed: Removed minor version number from program group name 16)..Updated: Help EurekaLog 7.0.02 hot-fix 1 (7.0.2.1), 12-September-2012 1)....Fixed: Range check error in Viewer 2)....Fixed: Bug in hooking code EurekaLog 7.0.02 (7.0.2.0), 11-September-2012 1)....Added: Improved memory problems detection 2)....Added: Minor IDE Expert usability improvements 3)....Added: Auto-size feature for detailed error dialog 4)....Added: Workaround for QC #106935 5)....Added: Workaround for bug in InvokeRegistry (SOAP/Mantis) 6)....Fixed: Nested OS exceptions 7)....Fixed: Multiply Win64 fixes 8)....Fixed: Compatibility mode fixes 9)....Fixed: Altered behaviour of "Add BugID/Date/ComputerName" options 10)..Fixed: Blank screenshots 11)..Fixed: Check file for corruptions 12)..Fixed: Viewer is unable to decrypt certain bug reports 13)..Fixed: Internal DoNoTouch option now works for post-processing and condtionals 14)..Fixed: Possible out of memory error for "Do not store class/procedure names" option 15)..Fixed: EurekaLog did not properly install itself when there is only Delphi installed, but no C++ Builder of the same version (or visa versa) 16)..Fixed: Wrong argument for OnRaise event 17)..Fixed: Handling memory errors in initialization/finalization sections 18)..Fixed: Updating steps to reproduce and user e-mail in bug report 19)..Fixed: Proper Success/Failure for some errors during SMTP send 20)..Added: Workaround for wrong GUI fonts 21)..Added: Delphi XE3 support 22)..Added: Individual options for each exception EurekaLog 7.0.01 (7.0.1.0), 28-June-2012 1)....Added: New "Modal window" option (MS Classic and EurekaLog dialogs) 2)....Added: New "Owned window" option (MS Classic and EurekaLog dialogs) 3)....Added: New "Catch EurekaLog IDE Expert errors" option 4)....Added: Backup memory manager to recover from critical errors 5)....Added: Alternative methods to provide additional features when memory filter is not set 6)....Fixed: Contains fixes from hotfixes 1-3 7)....Fixed: Performance improvements 8)....Fixed: Improved IDE Expert's speed, stability and compatibility with other 3rd party extensions 9)....Fixed: MS Classic dialog size adjustments for large "click here" translations 10)..Fixed: Fixed resetting few EurekaLog project options to defaults 11)..Fixed: Multiplying exception filters when options are assigned (for example: when switching to/from "Custom" page in project options) 12)..Fixed: (Compatibility mode) Fixed send options merging 13)..Fixed: Updated help EurekaLog 7.0 hot-fix 3 (7.0.0.273), 20-June-2012 --------------------------- 1)....Fixed: ERangeError in EResLeaks (THandle Integer) 2)....Fixed: C++ Builder breakpoints for large projects 3)....Fixed: Help (updates policy changed) 4)....Fixed: Text collections applying 5)....Fixed: Build events are now called for unlocked file 6)....Fixed: Proper handling of C++ Builder project options files from Delphi code (settings editor and IDE expert) 7)....Fixed: Terminate/Checked sub-option for MS Classic dialog 8)....Fixed: Confusing message for already post-processed executables 9)....Fixed: Access violation for some EurekaLog IDE menu items when no project was loaded 10)..Fixed: Invoking help for "Variables" window 11)..Fixed: EurekaLog Viewer version info 12)..Fixed: Events in components 13)..Added: Retry option for "Sorry, you must close all running IDE instances before installation" 14)..Added: Italian translation 15)..Added: Actual change log is now included into installer 16)..Added: Even more setup logging 17)..Added: New help articles (recompilation and manual installation) EurekaLog 7.0 hot-fix 2 (7.0.0.261), 10-June-2012 --------------------------- 1)....Fixed: Wrong version info reporting to IDE 2)....Added: Workaround for Delphi 2005 TListView bug 3)....Added: Workaround for possible invalid FPU state in exception handlers 4)....Added: Missed declarations for ExceptionLog (compatibility mode) 5)....Fixed: Work for unsaved projects 6)....Added: Escaping for '--' in options (confuses IDE's XML parsing) 7)....Added: Storing thread's class/name in call stack for terminated threads 8)....Added: More setup logging 9)....Fixed: Help (broken links) 10)..Added: "Upgrade to EurekaLog 7" help topic 11)..Fixed: Clean up installed files EurekaLog 7.0 hot-fix 1 (7.0.0.256), 6-June-2012 --------------------------- 1)....Fixed: Invalid Format() arguments in ELogBuilder. EurekaLog 7.0, 1-June-2012 --------------------------- 1)....Improved: Main change - EurekaLog's core was rewritten (refactored) to allow more easy modification and remove hacks. 2)....Improved: New plugin-like architecture now allows you to exclude unused code. 3)....Improved: New plugin-like architecture now allows you to easily extends EurekaLog. 4)....Improved: Greatly extended documentation. 5)....Improved: Installer is now localized. 6)....Improved: Greatly speed ups creation of minimal bug report (with most information disabled). 7)....Changed: EurekaLog's root IDE menu was relocated to under Tools and extended with new items. 8)....Added: New examples. 9)....Added: New tools (address lookup, error lookup, threads snapshot, standalone settings editor). 10)..Added: Support for DBG/PDB formats of debug information (including symbol server support and auto-downloading). 11)..Added: Support for madExcept debug information (experimental). 12)..Added: WER (Windows Error Reporting) support. 13)..Added: Full unicode support. 14)..Added: Professional and Trial editions: added source code (interface sections only) 15)..Improved: Dialogs - new options and new customization possibilities: 16)..Added: All GUI dialogs: ability to test dialog directly from configuration dialog by displaying a sample window with currently specified settings. 17)..Improved: All GUI dialogs: dialogs are DPI-awared now (auto-scale for different DPI). 18)..Added: MessageBox dialog: added detailed mode (shows a compact call stack). 19)..Added: MessageBox dialog: added ability for asking a send consent. 20)..Added: MessageBox dialog: added support to switch to "native" message box for application. 21)..Added: MS Classic dialog: added control over "user e-mail" edit's visibility. 22)..Added: MS Classic dialog: added ability to personalize dialog view with application's name and icon. 23)..Added: MS Classic dialog: added ability to show terminate/restart checkbox initially checked. 24)..Added: EurekaLog dialog: added ability to personalize dialog view with application's name and icon. 25)..Added: EurekaLog dialog: added ability to show terminate/restart checkbox initially checked. 26)..Added: EurekaLog dialog: added ability to switch back to non-detailed view. 27)..Added: WEB dialog: added new tags to customize bug report page. 28)..Improved: WEB dialog: improved support for unicode and charset. 29)..Added: New dialog type: RTL dialog. 30)..Added: New dialog type: console output. 31)..Added: New dialog type: system logging. 32)..Added: New dialog type: Windows Error Reporting. 33)..Improved: Sending - new options and new customization possibilities: 34)..Added: All send methods: added ability to setup multiply send methods. 35)..Added: All send methods: added ability to change send method order. 36)..Added: All send methods: added separate settings for each send method. 37)..Added: All send methods: ability to test send method directly from configuration dialog by sending a demo bug report. 38)..Added: SMTP client send method: added SSL support. 39)..Added: SMTP client send method: added TLS support. 40)..Added: SMTP client send method: added option for using real e-mail address. 41)..Added: SMTP server send method: added option for using real e-mail address. 42)..Added: HTTP upload send method: added support for custom backward feedback messages. 43)..Added: FTP upload send method: added creating folders on FTP (like remote ForceDirectories). 44)..Added: Mantis send method: added API support (MantisConnect, out-of-the-box since Mantis 1.1.0, available as add-on for previous versions). 45)..Added: Mantis send method: added support for custom "Count" field. 46)..Added: Mantis send method: added options for controlling duplicates. 47)..Added: Mantis send method: added support for SSL/TLS. 48)..Added: FogBugz send method: added API support (out-of-the-box since ForBugz 7, available as add-on for FogBugz 6). 49)..Added: FogBugz send method: EurekaLog will update "Occurrences" field (count of bugs). 50)..Added: FogBugz send method: EurekaLog will respect "Stop reporting" option (BugzScout's setting). 51)..Added: FogBugz send method: EurekaLog will respect "Scout message" option (BugzScout's setting). 52)..Added: FogBugz send method: EurekaLog will store client's e-mail as issue's correspondent. 53)..Added: FogBugz send method: added options for controlling duplicates. 54)..Added: FogBugz send method: added support for "Area" field. 55)..Added: FogBugz send method: added support for SSL/TLS. 56)..Added: BugZilla send method: added API support. 57)..Added: BugZilla send method: added support for custom "Count" field. 58)..Added: BugZilla send method: added options for controlling duplicates. 59)..Added: BugZilla send method: added support for SSL/TLS. 60)..Added: New send method: Shell (mailto protocol). 61)..Added: New send method: extended MAPI. 62)..Added: Support for separate code and debug info injection. 63)..Added: Ability to use custom units before EurekaLog's units. 64)..Added: Support for external configuration file in IDE expert. 65)..Added: Now EurekaLog stores only those project options which are different from defaults (to save disk space and reduce noise in project file). 66)..Added: Now EurekaLog stores project options sorted (alphabet order). 67)..Added: Separate settings for saving modules and processes lists to bug report. 68)..Added: Support for taking screenshots of multiply monitors. 69)..Added: More screenshot customization options. 70)..Added: More control over bug report's file names. 71)..Added: New environment variables. 72)..Added: Deleting .map file after compilation. 73)..Added: Support for different .dpr and .dproj file names. 74)..Improved: memory leaks detection feature - new options and new customization possibilities: 75)..Added: Ability to track memory problems without activation of leaks checking. 76)..Added: Support for sharing memory manager. 77)..Added: Support for tracking leaks in applications built with run-time packages. 78)..Added: Option to zero-fill freed memory. 79)..Added: Option to enable leaks detection only when running under debugger. 80)..Added: Option for manual activation control for leaks detection (via command-line switches). 81)..Added: Option to select stack tracing method for memory problems. 82)..Added: Option to trigger memory leak reporting only for large leaked memory's size. 83)..Added: Option to control limit of number of reported leak. 84)..Added: CheckHeap function to force check of heap's consistency. 85)..Added: DumpAllocationsToFile function to save information about allocated memory to log file. 86)..Added: Registered leaks feature. 87)..Added: Run-time control over memory leak registering. 88)..Added: New recognized leak type: String (both ANSI and Unicode are supported). 89)..Added: Memory features support for C++ Builder. 90)..Added: Resource leaks detection feature. 91)..Improved: Compilation speed increased. 92)..Added: Support for generics in debug information. 93)..Added: Chained/nested exceptions support. 94)..Added: Wait Chain Traversal support. 95)..Added: Support for named threads. 96)..Added: Additional information for threads in call stack. 97)..Improved: EurekaLog Viewer Tool: 98)..Added: Now Viewer has its own help file 99)..Added: Viewer now supports a FireBird based database on local file or remote server. 100).Added: You can have more that one user account for FireBird based database. 101).Added: Viewer now can be launched in View mode (Viewer can be configured to any DB or View mode). 102).Added: Viewer's database now supports storing files, associated with the report (you can also add and remove files manually). 103).Added: Viewer supports "Import" and "View" commands for report files. 104).Improved: Extended support for more log formats (XML, packed ELF, etc). 105).Added: Columns in report's list now can be configured (you can hide and show them). 106).Added: There are a plenty of new columns added to report's list. 107).Added: Ability of auto-download reports from e-mail account. 108).Improved: printing - now you can print the entire report (including screenshots). Old behaviour of printing just one tab (call stack only, for example) also remains. 109).Added: Viewer can now have more that one run-time instance . 110).Added: File import status dialog is now configurable (you can disable it, if you want to). 111).Added: There is a preview area for screenshots, available in reports. 112).Improved: Now Viewer is more Vista-friendly (i.e. file associations are managed in HKCU, rather that in HKLM, storing configuration in user's Application Data, etc, etc). 113).Added: Report's list now supports multi-select, so operations can be performed on many reports at time. 114).Added: There are plenty of new command line abilities, like specifying several files and new switches. 115).Improved: Bunch of minor changes and improvements. WARNING: -------- There are many changes in this release. See the "Changed from the old 6.x version" help topic for further information! EurekaLog 7 also have "EurekaLog 6 backward compatibility mode". Please, refer to help file for more information. We also have the detailed "Upgrade guide" in our help system.

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