Aggregate Functions 的中文意思

jing1979 2000-04-27 10:51:00

由于本人洋文太差看不懂sql在线帮助的几个函数的意思。准确的说是弄不明白意思
有没有更通俗一点的说明,特别是我们该用在什么地方。拜托各位高手
stdev
stdevp
grouping
var
varp

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Axiong 2000-05-06

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你所提的全是统计学上的所用到的。
stdev:返回指定组中所有值的标准方差
stdevp;返回指定组中所有值的入口标准方差
var:返回指定组中所有值的方差
varp:返回指定组中所有值的入口方差

jing1979 2000-04-28

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真没人用过这几个函数吗？

jing1979 2000-04-28

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你没弄懂我的意思。
你回答的好象我早就会。
我需要理解的是stdev,stdevp,grouping,var,varp的意思。
有人愿意帮我的话，分肯定会给。

929 2000-04-27

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Aggregate Functions 是聚合函数的意思，一般指对于一组数据中处理，比如MAX是取一组数据的最大值，类似的还有MIN，SUM等等。

中文名: 算法导论原名: Introduction to Algorithms 作者: Thomas H.Cormen, 达特茅斯学院计算机科学系副教授 Charles E.Leiserson, 麻省理工学院计算机科学与电气工程系教授 Ronald L.Rivest, 麻省理工学院计算机科学系Andrew与Erna Viterbi具名教授 Clifford Stein, 哥伦比亚大学工业工程与运筹学副教授资源格式: PDF（完整书签目录）出版社: The MIT Press ISBN 978-0-262-03384-8 (hardcover : alk. paper)—ISBN 978-0-262-53305-8 (pbk. : alk. paper) 发行时间: 2009年09月30日地区: 美国语言: 英文 1 The Role of Algorithms in Computing 5 1.1 Algorithms 5 1.2 Algorithms as a technology 11 2 Getting Started 16 2.1 Insertion sort 16 2.2 Analyzing algorithms 23 2.3 Designing algorithms 29 3 Growth of Functions 43 3.1 Asymptotic notation 43 3.2 Standard notations and common functions 53 4 Divide-and-Conquer 65 4.1 The maximum-subarray problem 68 4.2 Strassen's algorithm for matrix multiplication 75 4.3 The substitution method for solving recurrences 83 4.4 The recursion-tree method for solving recurrences 88 4.5 The master method for solving recurrences 93 4.6 Proof of the master theorem 97 5 Probabilistic Analysis and Randomized Algorithms 114 5.1 The hiring problem 114 5.2 Indicator random variables 118 5.3 Randomized algorithms 122 5.4 Probabilistic analysis and further uses of indicator random variables 130 II Sorting and Order Statistics Introduction 147 6 Heapsort 151 6.1 Heaps 151 6.2 Maintaining the heap property 154 6.3 Building a heap 156 6.4 The heapsort algorithm 159 6.5 Priority queues 162 7 Quicksort 170 7.1 Description of quicksort 170 7.2 Performance of quicksort 174 7.3 A randomized version of quicksort 179 7.4 Analysis of quicksort 180 8 Sorting in Linear Time 191 8.1 Lower bounds for sorting 191 8.2 Counting sort 194 8.3 Radix sort 197 8.4 Bucket sort 200 9 Medians and Order Statistics 213 9.1 Minimum and maximum 214 9.2 Selection in expected linear time 215 9.3 Selection in worst-case linear time 220 III Data Structures Introduction 229 10 Elementary Data Structures 232 10.1 Stacks and queues 232 10.2 Linked lists 236 10.3 Implementing pointers and objects 241 10.4 Representing rooted trees 246 11 Hash Tables 253 11.1 Direct-address tables 254 11.2 Hash tables 256 11.3 Hash functions 262 11.4 Open addressing 269 11.5 Perfect hashing 277 12 Binary Search Trees 286 12.1 What is a binary search tree? 286 12.2 Querying a binary search tree 289 12.3 Insertion and deletion 294 12.4 Randomly built binary search trees 299 13 Red-Black Trees 308 13.1 Properties of red-black trees 308 13.2 Rotations 312 13.3 Insertion 315 13.4 Deletion 323 14 Augmenting Data Structures 339 14.1 Dynamic order statistics 339 14.2 How to augment a data structure 345 14.3 Interval trees 348 IV Advanced Design and Analysis Techniques Introduction 357 15 Dynamic Programming 359 15.1 Rod cutting 360 15.2 Matrix-chain multiplication 370 15.3 Elements of dynamic programming 378 15.4 Longest common subsequence 390 15.5 Optimal binary search trees 397 16 Greedy Algorithms 414 16.1 An activity-selection problem 415 16.2 Elements of the greedy strategy 423 16.3 Huffman codes 428 16.4 Matroids and greedy methods 437 16.5 A task-scheduling problem as a matroid 443 17 Amortized Analysis 451 17.1 Aggregate analysis 452 17.2 The accounting method 456 17.3 The potential method 459 17.4 Dynamic tables 463 V Advanced Data Structures Introduction 481 18 B-Trees 484 18.1 Definition of B-trees 488 18.2 Basic operations on B-trees 491 18.3 Deleting a key from a B-tree 499 19 Fibonacci Heaps 505 19.1 Structure of Fibonacci heaps 507 19.2 Mergeable-heap operations 510 19.3 Decreasing a key and deleting a node 518 19.4 Bounding the maximum degree 523 20 van Emde Boas Trees 531 20.1 Preliminary approaches 532 20.2 A recursive structure 536 20.3 The van Emde Boas tree 545 21 Data Structures for Disjoint Sets 561 21.1 Disjoint-set operations 561 21.2 Linked-list representation of disjoint sets 564 21.3 Disjoint-set forests 568 21.4 Analysis of union by rank with path compression 573 VI Graph Algorithms Introduction 587 22 Elementary Graph Algorithms 589 22.1 Representations of graphs 589 22.2 Breadth-first search 594 22.3 Depth-first search 603 22.4 Topological sort 612 22.5 Strongly connected components 615 23 Minimum Spanning Trees 624 23.1 Growing a minimum spanning tree 625 23.2 The algorithms of Kruskal and Prim 631 24 Single-Source Shortest Paths 643 24.1 The Bellman-Ford algorithm 651 24.2 Single-source shortest paths in directed acyclic graphs 655 24.3 Dijkstra's algorithm 658 24.4 Difference constraints and shortest paths 664 24.5 Proofs of shortest-paths properties 671 25 All-Pairs Shortest Paths 684 25.1 Shortest paths and matrix multiplication 686 25.2 The Floyd-Warshall algorithm 693 25.3 Johnson's algorithm for sparse graphs 700 26 Maximum Flow 708 26.1 Flow networks 709 26.2 The Ford-Fulkerson method 714 26.3 Maximum bipartite matching 732 26.4 Push-relabel algorithms 736 26.5 The relabel-to-front algorithm 748 VII Selected Topics Introduction 769 27 Multithreaded Algorithms Sample Chapter - Download PDF (317 KB) 772 27.1 The basics of dynamic multithreading 774 27.2 Multithreaded matrix multiplication 792 27.3 Multithreaded merge sort 797 28 Matrix Operations 813 28.1 Solving systems of linear equations 813 28.2 Inverting matrices 827 28.3 Symmetric positive-definite matrices and least-squares approximation 832 29 Linear Programming 843 29.1 Standard and slack forms 850 29.2 Formulating problems as linear programs 859 29.3 The simplex algorithm 864 29.4 Duality 879 29.5 The initial basic feasible solution 886 30 Polynomials and the FFT 898 30.1 Representing polynomials 900 30.2 The DFT and FFT 906 30.3 Efficient FFT implementations 915 31 Number-Theoretic Algorithms 926 31.1 Elementary number-theoretic notions 927 31.2 Greatest common divisor 933 31.3 Modular arithmetic 939 31.4 Solving modular linear equations 946 31.5 The Chinese remainder theorem 950 31.6 Powers of an element 954 31.7 The RSA public-key cryptosystem 958 31.8 Primality testing 965 31.9 Integer factorization 975 32 String Matching 985 32.1 The naive string-matching algorithm 988 32.2 The Rabin-Karp algorithm 990 32.3 String matching with finite automata 995 32.4 The Knuth-Morris-Pratt algorithm 1002 33 Computational Geometry 1014 33.1 Line-segment properties 1015 33.2 Determining whether any pair of segments intersects 1021 33.3 Finding the convex hull 1029 33.4 Finding the closest pair of points 1039 34 NP-Completeness 1048 34.1 Polynomial time 1053 34.2 Polynomial-time verification 1061 34.3 NP-completeness and reducibility 1067 34.4 NP-completeness proofs 1078 34.5 NP-complete problems 1086 35 Approximation Algorithms 1106 35.1 The vertex-cover problem 1108 35.2 The traveling-salesman problem 1111 35.3 The set-covering problem 1117 35.4 Randomization and linear programming 1123 35.5 The subset-sum problem 1128 VIII Appendix: Mathematical Background Introduction 1143 A Summations 1145 A.1 Summation formulas and properties 1145 A.2 Bounding summations 1149 B Sets, Etc. 1158 B.1 Sets 1158 B.2 Relations 1163 B.3 Functions 1166 B.4 Graphs 1168 B.5 Trees 1173 C Counting and Probability 1183 C.1 Counting 1183 C.2 Probability 1189 C.3 Discrete random variables 1196 C.4 The geometric and binomial distributions 1201 C.5 The tails of the binomial distribution 1208 D Matrices 1217 D.1 Matrices and matrix operations 1217 D.2 Basic matrix properties 122

Database System Concepts——数据库系统概念第六版（英文版）作者： Abraham Silberschatz (Yale University) Henry F. Korth (Lehigh University) S. Sudarshan (Indian Institute of Technology, Bombay) 本书目录： Chapter 1 Introduction 1.1 Database-System Applications 1 1.2 Purpose of Database Systems 3 1.3 View of Data 6 1.4 Database Languages 9 1.5 Relational Databases 12 1.6 Database Design 15 1.7 Data Storage and Querying 20 1.8 Transaction Management 22 1.9 Database Architecture 23 1.10 Data Mining and Information Retrieval 25 1.11 Specialty Databases 26 1.12 Database Users and Administrators 27 1.13 History of Database Systems 29 1.14 Summary 31 Exercises 33 Bibliographical Notes 35 Chapter 2 Introduction to the RelationalModel 2.1 Structure of Relational Databases 39 2.2 Database Schema 42 2.3 Keys 45 2.4 Schema Diagrams 46 2.5 Relational Query Languages 47 2.6 Relational Operations 48 2.7 Summary 52 Exercises 53 Bibliographical Notes 55 Chapter 3 Introduction to SQL 3.1 Overview of the SQL Query Language 57 3.2 SQL Data Definition 58 3.3 Basic Structure of SQL Queries 63 3.4 Additional Basic Operations 74 3.5 Set Operations 79 3.6 Null Values 83 3.7 Aggregate Functions 84 3.8 Nested Subqueries 90 3.9 Modification of the Database 98 3.10 Summary 104 Exercises 105 Bibliographical Notes 112 Chapter 4 Intermediate SQL 4.1 Join Expressions 113 4.2 Views 120 4.3 Transactions 127 4.4 Integrity Constraints 128 4.5 SQL Data Types and Schemas 136 4.6 Authorization 143 4.7 Summary 150 Exercises 152 Bibliographical Notes 156 Chapter 5 Advanced SQL 5.1 Accessing SQL From a Programming Language 157 5.2 Functions and Procedures 173 5.3 Triggers 180 5.4 Recursive Queries 187 5.5 Advanced Aggregation Features 192 5.6 OLAP 197 5.7 Summary 209 Exercises 211 Bibliographical Notes 216 Chapter 6 Formal Relational Query Languages 6.1 The Relational Algebra 217 6.2 The Tuple Relational Calculus 239 6.3 The Domain Relational Calculus 245 6.4 Summary 248 Exercises 249 Bibliographical Notes 254 Chapter 7 Database Design and the E-R Model 7.1 Overview of the Design Process 259 7.2 The Entity-Relationship Model 262 7.3 Constraints 269 7.4 Removing Redundant Attributes in Entity Sets 272 7.5 Entity-Relationship Diagrams 274 7.6 Reduction to Relational Schemas 283 7.7 Entity-Relationship Design Issues 290 7.8 Extended E-R Features 295 7.9 Alternative Notations for Modeling Data 304 7.10 Other Aspects of Database Design 310 7.11 Summary 313 Exercises 315 Bibliographical Notes 321 Chapter 8 Relational Database Design 8.1 Features of Good Relational Designs 323 8.2 Atomic Domains and First Normal Form 327 8.3 Decomposition Using Functional Dependencies 329 8.4 Functional-Dependency Theory 338 8.5 Algorithms for Decomposition 348 8.6 Decomposition Using Multivalued Dependencies 355 8.7 More Normal Forms 360 8.8 Database-Design Process 361 8.9 Modeling Temporal Data 364 8.10 Summary 367 Exercises 368 Bibliographical Notes 374 Chapter 9 Application Design and Development 9.1 Application Programs and User Interfaces 375 9.2 Web Fundamentals 377 9.3 Servlets and JSP 383 9.4 Application Architectures 391 9.5 Rapid Application Development 396 9.6 Application Performance 400 9.7 Application Security 402 9.8 Encryption and Its Applications 411 9.9 Summary 417 Exercises 419 Bibliographical Notes 426 Chapter 10 Storage and File Structure 10.1 Overview of Physical Storage Media 429 10.2 Magnetic Disk and Flash Storage 432 10.3 RAID 441 10.4 Tertiary Storage 449 10.5 File Organization 451 10.6 Organization of Records in Files 457 10.7 Data-Dictionary Storage 462 10.8 Database Buffer 464 10.9 Summary 468 Exercises 470 Bibliographical Notes 473 Chapter 11 Indexing and Hashing 11.1 Basic Concepts 475 11.2 Ordered Indices 476 11.3 B+-Tree Index Files 485 11.4 B+-Tree Extensions 500 11.5 Multiple-Key Access 506 11.6 Static Hashing 509 11.7 Dynamic Hashing 515 11.8 Comparison of Ordered Indexing and Hashing 523 11.9 Bitmap Indices 524 11.10 Index Definition in SQL 528 11.11 Summary 529 Exercises 532 Bibliographical Notes 536 Chapter 12 Query Processing 12.1 Overview 537 12.2 Measures of Query Cost 540 12.3 Selection Operation 541 12.4 Sorting 546 12.5 Join Operation 549 12.6 Other Operations 563 12.7 Evaluation of Expressions 567 12.8 Summary 572 Exercises 574 Bibliographical Notes 577 Chapter 13 Query Optimization 13.1 Overview 579 13.2 Transformation of Relational Expressions 582 13.3 Estimating Statistics of Expression Results 590 13.4 Choice of Evaluation Plans 598 13.5 Materialized Views 607 13.6 Advanced Topics in Query Optimization 612 13.7 Summary 615 Exercises 617 Bibliographical Notes 622 Chapter 14 Transactions 14.1 Transaction Concept 627 14.2 A Simple Transaction Model 629 14.3 Storage Structure 632 14.4 Transaction Atomicity and Durability 633 14.5 Transaction Isolation 635 14.6 Serializability 641 14.7 Transaction Isolation and Atomicity 646 14.8 Transaction Isolation Levels 648 14.9 Implementation of Isolation Levels 650 14.10 Transactions as SQL Statements 653 14.11 Summary 655 Exercises 657 Bibliographical Notes 660 Chapter 15 Concurrency Control 15.1 Lock-Based Protocols 661 15.2 Deadlock Handling 674 15.3 Multiple Granularity 679 15.4 Timestamp-Based Protocols 682 15.5 Validation-Based Protocols 686 15.6 Multiversion Schemes 689 15.7 Snapshot Isolation 692 15.8 Insert Operations, Delete Operations, and Predicate Reads 697 15.9 Weak Levels of Consistency in Practice 701 15.10 Concurrency in Index Structures 704 15.11 Summary 708 Exercises 712 Bibliographical Notes 718 Chapter 16 Recovery System 16.1 Failure Classification 721 16.2 Storage 722 16.3 Recovery and Atomicity 726 16.4 Recovery Algorithm 735 16.5 Buffer Management 738 16.6 Failure with Loss of Nonvolatile Storage 743 16.7 Early Lock Release and Logical Undo Operations 744 16.8 ARIES 750 16.9 Remote Backup Systems 756 16.10 Summary 759 Exercises 762 Bibliographical Notes 766 Chapter 17 Database-System Architectures 17.1 Centralized and Client–Server Architectures 769 17.2 Server System Architectures 772 17.3 Parallel Systems 777 17.4 Distributed Systems 784 17.5 Network Types 788 17.6 Summary 791 Exercises 793 Bibliographical Notes 794 Chapter 18 Parallel Databases 18.1 Introduction 797 18.2 I/O Parallelism 798 18.3 Interquery Parallelism 802 18.4 Intraquery Parallelism 803 18.5 Intraoperation Parallelism 804 18.6 Interoperation Parallelism 813 18.7 Query Optimization 814 18.8 Design of Parallel Systems 815 18.9 Parallelism on Multicore Processors 817 18.10 Summary 819 Exercises 821 Bibliographical Notes 824 Chapter 19 Distributed Databases 19.1 Homogeneous and Heterogeneous Databases 825 19.2 Distributed Data Storage 826 19.3 Distributed Transactions 830 19.4 Commit Protocols 832 19.5 Concurrency Control in Distributed Databases 839 19.6 Availability 847 19.7 Distributed Query Processing 854 19.8 Heterogeneous Distributed Databases 857 19.9 Cloud-Based Databases 861 19.10 Directory Systems 870 19.11 Summary 875 Exercises 879 Bibliographical Notes 883 Chapter 20 DataWarehousing andMining 20.1 Decision-Support Systems 887 20.2 DataWarehousing 889 20.3 Data Mining 893 20.4 Classification 894 20.5 Association Rules 904 20.6 Other Types of Associations 906 20.7 Clustering 907 20.8 Other Forms of Data Mining 908 20.9 Summary 909 Exercises 911 Bibliographical Notes 914 Chapter 21 Information Retrieval 21.1 Overview 915 21.2 Relevance Ranking Using Terms 917 21.3 Relevance Using Hyperlinks 920 21.4 Synonyms, Homonyms, and Ontologies 925 21.5 Indexing of Documents 927 21.6 Measuring Retrieval Effectiveness 929 21.7 Crawling and Indexing the Web 930 21.8 Information Retrieval: Beyond Ranking of Pages 931 21.9 Directories and Categories 935 21.10 Summary 937 Exercises 939 Bibliographical Notes 941 Chapter 22 Object-Based Databases 22.1 Overview 945 22.2 Complex Data Types 946 22.3 Structured Types and Inheritance in SQL 949 22.4 Table Inheritance 954 22.5 Array and Multiset Types in SQL 956 22.6 Object-Identity and Reference Types in SQL 961 22.7 Implementing O-R Features 963 22.8 Persistent Programming Languages 964 22.9 Object-Relational Mapping 973 22.10 Object-Oriented versus Object-Relational 973 22.11 Summary 975 Exercises 976 Bibliographical Notes 980 Chapter 23 XML 23.1 Motivation 981 23.2 Structure of XML Data 986 23.3 XML Document Schema 990 23.4 Querying and Transformation 998 23.5 Application Program Interfaces to XML 1008 23.6 Storage of XML Data 1009 23.7 XML Applications 1016 23.8 Summary 1019 Exercises 1021 Bibliographical Notes 1024 PART EIGHT ADVANCED TOPICS Chapter 24 Advanced Application Development 24.1 Performance Tuning 1029 24.2 Performance Benchmarks 1045 24.3 Other Issues in Application Development 1048 24.4 Standardization 1051 24.5 Summary 1056 Exercises 1057 Bibliographical Notes 1059 Chapter 25 Spatial and Temporal Data andMobility 25.1 Motivation 1061 25.2 Time in Databases 1062 25.3 Spatial and Geographic Data 1064 25.4 Multimedia Databases 1076 25.5 Mobility and Personal Databases 1079 25.6 Summary 1085 Exercises 1087 Bibliographical Notes 1089 Chapter 26 Advanced Transaction Processing 26.1 Transaction-Processing Monitors 1091 26.2 TransactionalWorkflows 1096 26.3 E-Commerce 1102 26.4 Main-Memory Databases 1105 26.5 Real-Time Transaction Systems 1108 26.6 Long-Duration Transactions 1109 26.7 Summary 1115 Exercises 1117 Bibliographical Notes 1119 Chapter 27 PostgreSQL 27.1 Introduction 1123 27.2 User Interfaces 1124 27.3 SQL Variations and Extensions 1126 27.4 Transaction Management in PostgreSQL 1137 27.5 Storage and Indexing 1146 27.6 Query Processing and Optimization 1151 27.7 System Architecture 1154 Bibliographical Notes 1155 Chapter 28 Oracle 28.1 Database Design and Querying Tools 1157 28.2 SQL Variations and Extensions 1158 28.3 Storage and Indexing 1162 28.4 Query Processing and Optimization 1172 28.5 Concurrency Control and Recovery 1180 28.6 System Architecture 1183 28.7 Replication, Distribution, and External Data 1188 28.8 Database Administration Tools 1189 28.9 Data Mining 1191 Bibliographical Notes 1191 Chapter 29 IBM DB2 Universal Database 29.1 Overview 1193 29.2 Database-Design Tools 1194 29.3 SQL Variations and Extensions 1195 29.4 Storage and Indexing 1200 29.5 Multidimensional Clustering 1203 29.6 Query Processing and Optimization 1207 29.7 Materialized Query Tables 1212 29.8 Autonomic Features in DB2 1214 29.9 Tools and Utilities 1215 29.10 Concurrency Control and Recovery 1217 29.11 System Architecture 1219 29.12 Replication, Distribution, and External Data 1220 29.13 Business Intelligence Features 1221 Bibliographical Notes 1222 Chapter 30 Microsoft SQL Server 30.1 Management, Design, and Querying Tools 1223 30.2 SQL Variations and Extensions 1228 30.3 Storage and Indexing 1233 30.4 Query Processing and Optimization 1236 30.5 Concurrency and Recovery 1241 30.6 System Architecture 1246 30.7 Data Access 1248 30.8 Distributed Heterogeneous Query Processing 1250 30.9 Replication 1251 30.10 Server Programming in .NET 1253 30.11 XML Support 1258 30.12 SQL Server Service Broker 1261 30.13 Business Intelligence 1263 Bibliographical Notes 1267

中文名: 算法导论原名: Introduction to Algorithms 作者: Thomas H. Cormen Ronald L. Rivest Charles E. Leiserson Clifford Stein 资源格式: PDF 版本: 文字版出版社: The MIT Press书号: 978-0262033848发行时间: 2009年09月30日地区: 美国语言: 英文简介: 内容介绍: Editorial Reviews Review "In light of the explosive growth in the amount of data and the diversity of computing applications, efficient algorithms are needed now more than ever. This beautifully written, thoughtfully organized book is the definitive introductory book on the design and analysis of algorithms. The first half offers an effective method to teach and study algorithms; the second half then engages more advanced readers and curious students with compelling material on both the possibilities and the challenges in this fascinating field." —Shang-Hua Teng, University of Southern California "Introduction to Algorithms, the 'bible' of the field, is a comprehensive textbook covering the full spectrum of modern algorithms: from the fastest algorithms and data structures to polynomial-time algorithms for seemingly intractable problems, from classical algorithms in graph theory to special algorithms for string matching, computational geometry, and number theory. The revised third edition notably adds a chapter on van Emde Boas trees, one of the most useful data structures, and on multithreaded algorithms, a topic of increasing importance." —Daniel Spielman, Department of Computer Science, Yale University "As an educator and researcher in the field of algorithms for over two decades, I can unequivocally say that the Cormen book is the best textbook that I have ever seen on this subject. It offers an incisive, encyclopedic, and modern treatment of algorithms, and our department will continue to use it for teaching at both the graduate and undergraduate levels, as well as a reliable research reference." —Gabriel Robins, Department of Computer Science, University of Virginia Product Description Some books on algorithms are rigorous but incomplete; others cover masses of material but lack rigor. Introduction to Algorithms uniquely combines rigor and comprehensiveness. The book covers a broad range of algorithms in depth, yet makes their design and analysis accessible to all levels of readers. Each chapter is relatively self-contained and can be used as a unit of study. The algorithms are described in English and in a pseudocode designed to be readable by anyone who has done a little programming. The explanations have been kept elementary without sacrificing depth of coverage or mathematical rigor. The first edition became a widely used text in universities worldwide as well as the standard reference for professionals. The second edition featured new chapters on the role of algorithms, probabilistic analysis and randomized algorithms, and linear programming. The third edition has been revised and updated throughout. It includes two completely new chapters, on van Emde Boas trees and multithreaded algorithms, and substantial additions to the chapter on recurrences (now called "Divide-and-Conquer"). It features improved treatment of dynamic programming and greedy algorithms and a new notion of edge-based flow in the material on flow networks. Many new exercises and problems have been added for this edition. As of the third edition, this textbook is published exclusively by the MIT Press. About the Author Thomas H. Cormen is Professor of Computer Science and former Director of the Institute for Writing and Rhetoric at Dartmouth College. Charles E. Leiserson is Professor of Computer Science and Engineering at the Massachusetts Institute of Technology. Ronald L. Rivest is Andrew and Erna Viterbi Professor of Electrical Engineering and Computer Science at the Massachusetts Institute of Technology. Clifford Stein is Professor of Industrial Engineering and Operations Research at Columbia University. 目录: Introduction 3 1 The Role of Algorithms in Computing 5 1.1 Algorithms 5 1.2 Algorithms as a technology 11 2 Getting Started 16 2.1 Insertion sort 16 2.2 Analyzing algorithms 23 2.3 Designing algorithms 29 3 Growth of Functions 43 3.1 Asymptotic notation 43 3.2 Standard notations and common functions 53 4 Divide-and-Conquer 65 4.1 The maximum-subarray problem 68 4.2 Strassen's algorithm for matrix multiplication 75 4.3 The substitution method for solving recurrences 83 4.4 The recursion-tree method for solving recurrences 88 4.5 The master method for solving recurrences 93 4.6 Proof of the master theorem 97 5 Probabilistic Analysis and Randomized Algorithms 114 5.1 The hiring problem 114 5.2 Indicator random variables 118 5.3 Randomized algorithms 122 5.4 Probabilistic analysis and further uses of indicator random variables 130 II Sorting and Order Statistics Introduction 147 6 Heapsort 151 6.1 Heaps 151 6.2 Maintaining the heap property 154 6.3 Building a heap 156 6.4 The heapsort algorithm 159 6.5 Priority queues 162 7 Quicksort 170 7.1 Description of quicksort 170 7.2 Performance of quicksort 174 7.3 A randomized version of quicksort 179 7.4 Analysis of quicksort 180 8 Sorting in Linear Time 191 8.1 Lower bounds for sorting 191 8.2 Counting sort 194 8.3 Radix sort 197 8.4 Bucket sort 200 9 Medians and Order Statistics 213 9.1 Minimum and maximum 214 9.2 Selection in expected linear time 215 9.3 Selection in worst-case linear time 220 III Data Structures Introduction 229 10 Elementary Data Structures 232 10.1 Stacks and queues 232 10.2 Linked lists 236 10.3 Implementing pointers and objects 241 10.4 Representing rooted trees 246 11 Hash Tables 253 11.1 Direct-address tables 254 11.2 Hash tables 256 11.3 Hash functions 262 11.4 Open addressing 269 11.5 Perfect hashing 277 12 Binary Search Trees 286 12.1 What is a binary search tree? 286 12.2 Querying a binary search tree 289 12.3 Insertion and deletion 294 12.4 Randomly built binary search trees 299 13 Red-Black Trees 308 13.1 Properties of red-black trees 308 13.2 Rotations 312 13.3 Insertion 315 13.4 Deletion 323 14 Augmenting Data Structures 339 14.1 Dynamic order statistics 339 14.2 How to augment a data structure 345 14.3 Interval trees 348 IV Advanced Design and Analysis Techniques Introduction 357 15 Dynamic Programming 359 15.1 Rod cutting 360 15.2 Matrix-chain multiplication 370 15.3 Elements of dynamic programming 378 15.4 Longest common subsequence 390 15.5 Optimal binary search trees 397 16 Greedy Algorithms 414 16.1 An activity-selection problem 415 16.2 Elements of the greedy strategy 423 16.3 Huffman codes 428 16.4 Matroids and greedy methods 437 16.5 A task-scheduling problem as a matroid 443 17 Amortized Analysis 451 17.1 Aggregate analysis 452 17.2 The accounting method 456 17.3 The potential method 459 17.4 Dynamic tables 463 V Advanced Data Structures Introduction 481 18 B-Trees 484 18.1 Definition of B-trees 488 18.2 Basic operations on B-trees 491 18.3 Deleting a key from a B-tree 499 19 Fibonacci Heaps 505 19.1 Structure of Fibonacci heaps 507 19.2 Mergeable-heap operations 510 19.3 Decreasing a key and deleting a node 518 19.4 Bounding the maximum degree 523 20 van Emde Boas Trees 531 20.1 Preliminary approaches 532 20.2 A recursive structure 536 20.3 The van Emde Boas tree 545 21 Data Structures for Disjoint Sets 561 21.1 Disjoint-set operations 561 21.2 Linked-list representation of disjoint sets 564 21.3 Disjoint-set forests 568 21.4 Analysis of union by rank with path compression 573 VI Graph Algorithms Introduction 587 22 Elementary Graph Algorithms 589 22.1 Representations of graphs 589 22.2 Breadth-first search 594 22.3 Depth-first search 603 22.4 Topological sort 612 22.5 Strongly connected components 615 23 Minimum Spanning Trees 624 23.1 Growing a minimum spanning tree 625 23.2 The algorithms of Kruskal and Prim 631 24 Single-Source Shortest Paths 643 24.1 The Bellman-Ford algorithm 651 24.2 Single-source shortest paths in directed acyclic graphs 655 24.3 Dijkstra's algorithm 658 24.4 Difference constraints and shortest paths 664 24.5 Proofs of shortest-paths properties 671 25 All-Pairs Shortest Paths 684 25.1 Shortest paths and matrix multiplication 686 25.2 The Floyd-Warshall algorithm 693 25.3 Johnson's algorithm for sparse graphs 700 26 Maximum Flow 708 26.1 Flow networks 709 26.2 The Ford-Fulkerson method 714 26.3 Maximum bipartite matching 732 26.4 Push-relabel algorithms 736 26.5 The relabel-to-front algorithm 748 VII Selected Topics Introduction 769 27 Multithreaded Algorithms Sample Chapter - Download PDF (317 KB) 772 27.1 The basics of dynamic multithreading 774 27.2 Multithreaded matrix multiplication 792 27.3 Multithreaded merge sort 797 28 Matrix Operations 813 28.1 Solving systems of linear equations 813 28.2 Inverting matrices 827 28.3 Symmetric positive-definite matrices and least-squares approximation 832 29 Linear Programming 843 29.1 Standard and slack forms 850 29.2 Formulating problems as linear programs 859 29.3 The simplex algorithm 864 29.4 Duality 879 29.5 The initial basic feasible solution 886 30 Polynomials and the FFT 898 30.1 Representing polynomials 900 30.2 The DFT and FFT 906 30.3 Efficient FFT implementations 915 31 Number-Theoretic Algorithms 926 31.1 Elementary number-theoretic notions 927 31.2 Greatest common divisor 933 31.3 Modular arithmetic 939 31.4 Solving modular linear equations 946 31.5 The Chinese remainder theorem 950 31.6 Powers of an element 954 31.7 The RSA public-key cryptosystem 958 31.8 Primality testing 965 31.9 Integer factorization 975 32 String Matching 985 32.1 The naive string-matching algorithm 988 32.2 The Rabin-Karp algorithm 990 32.3 String matching with finite automata 995 32.4 The Knuth-Morris-Pratt algorithm 1002 33 Computational Geometry 1014 33.1 Line-segment properties 1015 33.2 Determining whether any pair of segments intersects 1021 33.3 Finding the convex hull 1029 33.4 Finding the closest pair of points 1039 34 NP-Completeness 1048 34.1 Polynomial time 1053 34.2 Polynomial-time verification 1061 34.3 NP-completeness and reducibility 1067 34.4 NP-completeness proofs 1078 34.5 NP-complete problems 1086 35 Approximation Algorithms 1106 35.1 The vertex-cover problem 1108 35.2 The traveling-salesman problem 1111 35.3 The set-covering problem 1117 35.4 Randomization and linear programming 1123 35.5 The subset-sum problem 1128 VIII Appendix: Mathematical Background Introduction 1143 A Summations 1145 A.1 Summation formulas and properties 1145 A.2 Bounding summations 1149 B Sets, Etc. 1158 B.1 Sets 1158 B.2 Relations 1163 B.3 Functions 1166 B.4 Graphs 1168 B.5 Trees 1173 C Counting and Probability 1183 C.1 Counting 1183 C.2 Probability 1189 C.3 Discrete random variables 1196 C.4 The geometric and binomial distributions 1201 C.5 The tails of the binomial distribution 1208 D Matrices 1217 D.1 Matrices and matrix operations 1217 D.2 Basic matrix properties 122

Table of Contents Section 1 Introduction to SystemVerilog ...................................................................................................... 1 Section 2 Literal Values.................................................................................................................................. 4 2.1 Introduction (informative) ...............................................................................................................4 2.2 Literal value syntax..........................................................................................................................4 2.3 Integer and logic literals ..................................................................................................................4 2.4 Real literals ......................................................................................................................................5 2.5 Time literals .....................................................................................................................................5 2.6 String literals....................................................................................................................................5 2.7 Array literals ....................................................................................................................................6 2.8 Structure literals ...............................................................................................................................6 Section 3 Data Types....................................................................................................................................... 8 3.1 Introduction (informative) ...............................................................................................................8 3.2 Data type syntax...............................................................................................................................9 3.3 Integer data types ...........................................................................................................................10 3.4 Real and shortreal data types .........................................................................................................11 3.5 Void data type ................................................................................................................................11 3.6 chandle data type ...........................................................................................................................11 3.7 String data type ..............................................................................................................................12 3.8 Event data type...............................................................................................................................16 3.9 User-defined types .........................................................................................................................16 3.10 Enumerations .................................................................................................................................17 3.11 Structures and unions.....................................................................................................................22 3.12 Class...............................................................................................................................................26 3.13 Singular and aggregate types .........................................................................................................27 3.14 Casting ...........................................................................................................................................27 3.15 $cast dynamic casting ....................................................................................................................28 3.16 Bit-stream casting ..........................................................................................................................29 Section 4 Arrays ............................................................................................................................................ 32 4.1 Introduction (informative) .............................................................................................................32 4.2 Packed and unpacked arrays ..........................................................................................................32 4.3 Multiple dimensions ......................................................................................................................33 4.4 Indexing and slicing of arrays........................................................................................................34 4.5 Array querying functions ...............................................................................................................35 4.6 Dynamic arrays ..............................................................................................................................35 4.7 Array assignment ...........................................................................................................................37 4.8 Arrays as arguments.......................................................................................................................38 4.9 Associative arrays ..........................................................................................................................39 4.10 Associative array methods .............................................................................................................41 4.11 Associative array assignment.........................................................................................................44 4.12 Associative array arguments ..........................................................................................................44 4.13 Associative array literals................................................................................................................44 4.14 Queues ...........................................................................................................................................45 4.15 Array manipulation methods .........................................................................................................47 Section 5 Data Declarations ......................................................................................................................... 52 5.1 Introduction (informative) .............................................................................................................52 5.2 Data declaration syntax..................................................................................................................52 5.3 Constants........................................................................................................................................52 Accellera SystemVerilog 3.1a Extensions to Verilog-2001 viii Copyright 2004 Accellera. All rights reserved . 5.4 Variables ........................................................................................................................................53 5.5 Scope and lifetime .........................................................................................................................54 5.6 Nets, regs, and logic.......................................................................................................................55 5.7 Signal aliasing................................................................................................................................56 5.8 Type compatibility .........................................................................................................................58 Section 6 Attributes....................................................................................................................................... 61 6.1 Introduction (informative) .............................................................................................................61 6.2 Default attribute type .....................................................................................................................61 Section 7 Operators and Expressions.......................................................................................................... 62 7.1 Introduction (informative) .............................................................................................................62 7.2 Operator syntax..............................................................................................................................62 7.3 Assignment operators ....................................................................................................................62 7.4 Operations on logic and bit types ..................................................................................................63 7.5 Wild equality and wild inequality..................................................................................................63 7.6 Real operators ................................................................................................................................64 7.7 Size.................................................................................................................................................64 7.8 Sign ................................................................................................................................................64 7.9 Operator precedence and associativity ..........................................................................................64 7.10 Built-in methods ............................................................................................................................65 7.11 Static Prefixes ................................................................................................................................66 7.12 Concatenation ................................................................................................................................67 7.13 Unpacked array expressions ..........................................................................................................67 7.14 Structure expressions .....................................................................................................................68 7.15 Tagged union expressions and member access..............................................................................70 7.16 Aggregate expressions ...................................................................................................................71 7.17 Operator overloading .....................................................................................................................72 7.18 Streaming operators (pack / unpack) .............................................................................................73 7.19 Conditional operator ......................................................................................................................77 7.20 Set membership..............................................................................................................................77 Section 8 Procedural Statements and Control Flow.................................................................................. 79 8.1 Introduction (informative) .............................................................................................................79 8.2 Statements ......................................................................................................................................79 8.3 Blocking and nonblocking assignments ........................................................................................80 8.4 Selection statements.......................................................................................................................81 8.5 Loop statements .............................................................................................................................87 8.6 Jump statements.............................................................................................................................89 8.7 Final blocks....................................................................................................................................89 8.8 Named blocks and statement labels ...............................................................................................90 8.9 Disable ...........................................................................................................................................90 8.10 Event control..................................................................................................................................91 8.11 Level-sensitive sequence controls .................................................................................................93 8.12 Procedural assign and deassign removal .......................................................................................94 Section 9 Processes........................................................................................................................................ 95 9.1 Introduction (informative) .............................................................................................................95 9.2 Combinational logic.......................................................................................................................95 9.3 Latched logic..................................................................................................................................96 9.4 Sequential logic..............................................................................................................................96 9.5 Continuous assignments ................................................................................................................96 9.6 fork...join........................................................................................................................................97 9.7 Process execution threads ..............................................................................................................98 Accellera Extensions to Verilog-2001 SystemVerilog 3.1a Copyright 2004 Accellera. All rights reserved. ix 9.8 Process control ...............................................................................................................................98 9.9 Fine-grain process control ...........................................................................................................100 Section 10 Tasks and Functions................................................................................................................... 102 10.1 Introduction (informative) ...........................................................................................................102 10.2 Tasks ............................................................................................................................................103 10.3 Functions......................................................................................................................................104 10.4 Task and function argument passing ...........................................................................................106 10.5 Import and export functions.........................................................................................................109 Section 11 Classes.......................................................................................................................................... 111 11.1 Introduction (informative) ...........................................................................................................111 11.2 Syntax ..........................................................................................................................................112 11.3 Overview......................................................................................................................................113 11.4 Objects (class instance)................................................................................................................113 11.5 Object properties..........................................................................................................................114 11.6 Object methods ............................................................................................................................114 11.7 Constructors .................................................................................................................................115 11.8 Static class properties...................................................................................................................116 11.9 Static methods..............................................................................................................................116 11.10 This ..............................................................................................................................................116 11.11 Assignment, re-naming and copying ...........................................................................................117 11.12 Inheritance and subclasses ...........................................................................................................118 11.13 Overridden members....................................................................................................................119 11.14 Super ............................................................................................................................................119 11.15 Casting .........................................................................................................................................120 11.16 Chaining constructors ..................................................................................................................120 11.17 Data hiding and encapsulation .....................................................................................................121 11.18 Constant class properties .............................................................................................................121 11.19 Abstract classes and virtual methods ...........................................................................................122 11.20 Polymorphism: dynamic method lookup.....................................................................................123 11.21 Class scope resolution operator :: ................................................................................................123 11.22 Out of block declarations .............................................................................................................124 11.23 Parameterized classes ..................................................................................................................125 11.24 Typedef class ...............................................................................................................................126 11.25 Classes and structures ..................................................................................................................126 11.26 Memory management ..................................................................................................................127 Section 12 Random Constraints .................................................................................................................. 128 12.1 Introduction (informative) ...........................................................................................................128 12.2 Overview......................................................................................................................................128 12.3 Random variables ........................................................................................................................131 12.4 Constraint blocks .........................................................................................................................132 12.5 Randomization methods ..............................................................................................................145 12.6 In-line constraints — randomize() with.......................................................................................147 12.7 Disabling random variables with rand_mode() ...........................................................................148 12.8 Controlling constraints with constraint_mode() ..........................................................................149 12.9 Dynamic constraint modification.................................................................................................150 12.10 In-line random variable control ...................................................................................................150 12.11 Randomization of scope variables — std::randomize()...............................................................151 12.12 Random number system functions and methods .........................................................................153 12.13Random stability ..........................................................................................................................154 12.14 Manually seeding randomize .......................................................................................................156 12.15 Random weighted case — randcase ............................................................................................157 Accellera SystemVerilog 3.1a Extensions to Verilog-2001 x Copyright 2004 Accellera. All rights reserved . 12.16 Random sequence generation — randsequence...........................................................................158 Section 13 Interprocess Synchronization and Communication................................................................ 166 13.1 Introduction (informative) ...........................................................................................................166 13.2 Semaphores ..................................................................................................................................166 13.3 Mailboxes.....................................................................................................................................167 13.4 Parameterized mailboxes .............................................................................................................170 13.5 Event ............................................................................................................................................171 13.6 Event sequencing: wait_order() ...................................................................................................172 13.7 Event variables.............................................................................................................................173 Section 14 Scheduling Semantics................................................................................................................. 176 14.1 Execution of a hardware model and its verification environment ...............................................176 14.2 Event simulation ..........................................................................................................................176 14.3 The stratified event scheduler ......................................................................................................176 14.4 The PLI callback control points...................................................................................................180 Section 15 Clocking Blocks .......................................................................................................................... 181 15.1 Introduction (informative) ...........................................................................................................181 15.2 Clocking block declaration ..........................................................................................................181 15.3 Input and output skews ................................................................................................................183 15.4 Hierarchical expressions ..............................................................................................................184 15.5 Signals in multiple clocking blocks .............................................................................................185 15.6 Clocking block scope and lifetime...............................................................................................185 15.7 Multiple clocking blocks example ...............................................................................................185 15.8 Interfaces and clocking blocks.....................................................................................................186 15.9 Clocking block events..................................................................................................................187 15.10 Cycle delay: ## ............................................................................................................................187 15.11 Default clocking...........................................................................................................................188 15.12 Input sampling .............................................................................................................................189 15.13 Synchronous events .....................................................................................................................189 15.14 Synchronous drives......................................................................................................................190 Section 16 Program Block............................................................................................................................ 193 16.1 Introduction (informative) ...........................................................................................................193 16.2 The program construct .................................................................................................................193 16.3 Multiple programs........................................................................................................................195 16.4 Eliminating testbench races .........................................................................................................195 16.5 Blocking tasks in cycle/event mode.............................................................................................196 16.6 Program control tasks ..................................................................................................................196 Section 17 Assertions ................................................................................................................................... 198 17.1 Introduction (informative) ...........................................................................................................198 17.2 Immediate assertions....................................................................................................................198 17.3 Concurrent assertions overview...................................................................................................200 17.4 Boolean expressions ....................................................................................................................201 17.5 Sequences.....................................................................................................................................203 17.6 Declaring sequences ....................................................................................................................206 17.7 Sequence operations ....................................................................................................................208 17.8 Manipulating data in a sequence..................................................................................................224 17.9 Calling subroutines on match of a sequence................................................................................228 17.10 System functions..........................................................................................................................229 17.11 Declaring properties.....................................................................................................................229 17.12 Multiple clock support .................................................................................................................240 Accellera Extensions to Verilog-2001 SystemVerilog 3.1a Copyright 2004 Accellera. All rights reserved. xi 17.13 Concurrent assertions...................................................................................................................246 17.14 Clock resolution ...........................................................................................................................252 17.15 Binding properties to scopes or instances....................................................................................258 17.16 The expect statement ...................................................................................................................259 Section 18 Hierarchy..................................................................................................................................... 261 18.1 Introduction (informative) ...........................................................................................................261 18.2 Packages.......................................................................................................................................261 18.3 Compilation unit support .............................................................................................................265 18.4 Top-level instance........................................................................................................................266 18.5 Module declarations.....................................................................................................................267 18.6 Nested modules............................................................................................................................267 18.7 Extern modules ............................................................................................................................269 18.8 Port declarations ..........................................................................................................................270 18.9 List of port expressions................................................................................................................271 18.10 Time unit and precision ...............................................................................................................271 18.11 Module instances .........................................................................................................................272 18.12 Port connection rules ...................................................................................................................276 18.13 Name spaces ................................................................................................................................277 18.14 Hierarchical names ......................................................................................................................278 Section 19 Interfaces ..................................................................................................................................... 279 19.1 Introduction (informative) ...........................................................................................................279 19.2 Interface syntax............................................................................................................................280 19.3 Ports in interfaces.........................................................................................................................284 19.4 Modports ......................................................................................................................................285 19.5 Interfaces and specify blocks .......................................................................................................291 19.6 Tasks and functions in interfaces.................................................................................................291 19.7 Parameterized interfaces ..............................................................................................................297 19.8 Virtual interfaces..........................................................................................................................299 19.9 Access to interface objects...........................................................................................................303 Section 20 Coverage...................................................................................................................................... 305 20.1 Introduction (informative) ...........................................................................................................305 20.2 Defining the coverage model: covergroup...................................................................................306 20.3 Using covergroup in classes ........................................................................................................308 20.4 Defining coverage points .............................................................................................................309 20.5 Defining cross coverage...............................................................................................................315 20.6 Specifying coverage options ........................................................................................................319 20.7 Predefined coverage methods ......................................................................................................324 20.8 Predefined coverage system tasks and functions .........................................................................324 20.9 Organization of option and type_option members ......................................................................324 Section 21 Parameters .................................................................................................................................. 326 21.1 Introduction (informative) ...........................................................................................................326 21.2 Parameter declaration syntax .......................................................................................................327 Section 22 Configuration Libraries............................................................................................................. 330 22.1 Introduction (informative) ...........................................................................................................330 22.2 Libraries .......................................................................................................................................330 Section 23 System Tasks and System Functions ........................................................................................ 331 23.1 Introduction (informative) ...........................................................................................................331 23.2 Elaboration-time typeof function.................................................................................................331 Accellera SystemVerilog 3.1a Extensions to Verilog-2001 xii Copyright 2004 Accellera. All rights reserved . 23.3 Typename function ......................................................................................................................331 23.4 Expression size system function ..................................................................................................332 23.5 Range system function.................................................................................................................333 23.6 Shortreal conversions...................................................................................................................333 23.7 Array querying system functions .................................................................................................334 23.8 Assertion severity system tasks ...................................................................................................335 23.9 Assertion control system tasks.....................................................................................................336 23.10 Assertion system functions ..........................................................................................................336 23.11 Random number system functions...............................................................................................337 23.12 Program control ...........................................................................................................................337 23.13 Coverage system functions ..........................................................................................................337 23.14 Enhancements to Verilog-2001 system tasks ..............................................................................337 23.15 $readmemb and $readmemh........................................................................................................338 23.16 $writememb and $writememh .....................................................................................................338 23.17 File format considerations for multi-dimensional unpacked arrays ............................................339 23.18 System task arguments for multi-dimensional unpacked arrays .................................................340 Section 24 VCD Data .................................................................................................................................... 342 Section 25 Compiler Directives.................................................................................................................... 343 25.1 Introduction (informative) ...........................................................................................................343 25.2 ‘define macros..............................................................................................................................343 25.3 `include ........................................................................................................................................344 Section 26 Features under consideration for removal from SystemVerilog ........................................... 345 26.1 Introduction (informative) ...........................................................................................................345 26.2 Defparam statements....................................................................................................................345 26.3 Procedural assign and deassign statements..................................................................................345 Section 27 Direct Programming Interface (DPI) ....................................................................................... 347 27.1 Overview......................................................................................................................................347 27.2 Two layers of the DPI ..................................................................................................................348 27.3 Global name space of imported and exported functions..............................................................349 27.4 Imported tasks and functions .......................................................................................................349 27.5 Calling imported functions ..........................................................................................................355 27.6 Exported functions .......................................................................................................................356 27.7 Exported tasks..............................................................................................................................357 27.8 Disabling DPI tasks and functions...............................................................................................357 Section 28 SystemVerilog Assertion API .................................................................................................... 359 28.1 Requirements ...............................................................................................................................359 28.2 Extensions to VPI enumerations..................................................................................................359 28.3 Static information ........................................................................................................................360 28.4 Dynamic information ...................................................................................................................363 28.5 Control functions .........................................................................................................................366 Section 29 SystemVerilog Coverage API .................................................................................................... 368 29.1 Requirements ...............................................................................................................................368 29.2 SystemVerilog real-time coverage access ...................................................................................369 29.3 FSM recognition ..........................................................................................................................374 29.4 VPI coverage extensions..............................................................................................................377 Section 30 SystemVerilog Data Read API .................................................................................................. 381 30.1 Introduction (informative) ...........................................................................................................381 Accellera Extensions to Verilog-2001 SystemVerilog 3.1a Copyright 2004 Accellera. All rights reserved. xiii 30.2 Requirements ...............................................................................................................................381 30.3 Extensions to VPI enumerations..................................................................................................382 30.4 VPI object type additions.............................................................................................................383 30.5 Object model diagrams ................................................................................................................385 30.6 Usage extensions to VPI routines ................................................................................................387 30.7 VPI routines added in SystemVerilog .........................................................................................388 30.8 Reading data ................................................................................................................................389 30.9 Optionally unloading the data......................................................................................................399 30.10 Reading data from multiple databases and/or different read library providers ...........................399 30.11VPI routines extended in SystemVerilog.....................................................................................402 30.12VPI routines added in SystemVerilog .........................................................................................403 Section 31 SystemVerilog VPI Object Model............................................................................................. 407 31.1 Introduction (informative) ...........................................................................................................407 31.2 Instance .......................................................................................................................................409 31.3 Interface ......................................................................................................................................410 31.4 Program........................................................................................................................................410 31.5 Module (supersedes IEEE 1364-2001 26.6.1) ............................................................................411 31.6 Modport ......................................................................................................................................412 31.7 Interface tf decl ............................................................................................................................412 31.8 Ports (supersedes IEEE 1364-2001 26.6.5) .................................................................................413 31.9 Ref Obj.........................................................................................................................................414 31.10 Variables (supersedes IEEE 1364-2001 section 26.6.8) .............................................................416 31.11 Var Select (supersedes IEEE 1364-2001 26.6.8).........................................................................418 31.12 Typespec ......................................................................................................................................419 31.13 Variable Drivers and Loads (supersedes IEEE 1364-2001 26.6.23) ...........................................421 31.14 Instance Arrays (supersedes IEEE 1364-2001 26.6.2) ................................................................421 31.15 Scope (supersedes IEEE 1364-2001 26.6.3) ...............................................................................422 31.16 IO Declaration (supersedes IEEE 1364-2001 26.6.4) .................................................................423 31.17 Clocking Block ...........................................................................................................................424 31.18 Class Object Definition................................................................................................................425 31.19 Constraint, constraint ordering, distribution, ...............................................................................426 31.20 Constraint expression...................................................................................................................427 31.21 Class Variables ...........................................................................................................................428 31.23 Named Events (supersedes IEEE 1364-2001 26.6.11) ................................................................430 31.24 Task, Function Declaration (supersedes IEEE 1364-2001 26.6.18)............................................431 31.25 Alias Statement ...........................................................................................................................432 31.26 Frames (supersedes IEEE 1364-2001 26.6.20)............................................................................433 31.27 Threads.........................................................................................................................................434 31.28 tf call (supersedes IEEE 1364-2001 26.6.19) ..............................................................................435 31.29 Module path, path term (supersedes IEEE 1364-2001 26.6.15) .................................................436 31.30 Concurrent assertions ..................................................................................................................437 31.31 Property Decl ..............................................................................................................................437 31.32 Property Specification .................................................................................................................438 31.33 Multiclock Sequence Expression ................................................................................................439 31.34 Sequence Declaration .................................................................................................................440 31.35 Sequence Expression ..................................................................................................................441 31.36 Attribute (supersedes IEEE 1364-2001 26.6.42) ........................................................................442 31.37 Atomic Statement (supersedes IEEE 1364-2001 26.6.27) .........................................................443 31.38 If, if else, return, case, do while (supersedes IEEE 1364-2001 26.6.35, 26.6.36).......................444 31.39 waits, disables, expect, foreach (supersedes IEEE 1364 26.6.38) ...............................................445 31.40 Simple expressions (supersedes IEEE 1364-2001 26.6.25) ........................................................446 31.41 Expressions (supersedes IEEE 1364-2001 26.6.26) ....................................................................447 31.42 Event control (supersedes IEEE 1364-2001 26.6.30)..................................................................448 Accellera SystemVerilog 3.1a Extensions to Verilog-2001 xiv Copyright 2004 Accellera. All rights reserved . 31.43 Event stmt (supersedes IEEE 1364-2001 26.6.27) .....................................................................448 31.44 Process (supersedes IEEE 1364-2001 26.6.27) ..........................................................................449 31.45 Assignment (supersedes IEEE 1364-2001 26.6.28) ...................................................................449 Annex A Formal Syntax.............................................................................................................................. 451 Annex B Keywords ...................................................................................................................................... 488 Annex C Std Package ................................................................................................................................. 490 Annex D Linked Lists................................................................................................................................. 492 Annex E DPI C-layer .................................................................................................................................. 498 Annex F Include files .................................................................................................................................. 523 Annex G Inclusion of Foreign Language Code ......................................................................................... 529 Annex H Formal Semantics of Concurrent Assertions ............................................................................ 533 Annex I sv_vpi_user.h................................................................................................................................ 544 Annex J Glossary ........................................................................................................................................ 553 Annex K Bibliography................................................................................................................................. 555 Index 557

Oracle P/L SQL实现发送Email、浏览网页等网络操作功能 Oracle P/L SQL实现发送Email、浏览网页等网络操作功能，以下是此过程包的头部，包体经常打包处理plb，感兴趣用户可以下载下来。 --.使用聚合函数实现多行合并 Drop Type Strcat_type; Drop Function f_StrCat; Drop Package UTL_INet; Variable ls_ObjectName VarChar2(128); Begin Select Sequence_Name Into :ls_ObjectName From User_Sequences Where Sequence_Name = 'SYS_RAND_ID'; DBMS_Output.Put_Line( :ls_ObjectName ); Exception When No_Data_Found Then Execute Immediate 'Create Sequence SYS_RAND_ID minvalue 1 maxValue 99999999999999999 Start With 1 increment by 1 cache 5 cycle order'; End; / --1、创建类型 Create Or Replace Type Strcat_type As Object ( cat_string varchar2(4000), Static Function ODCIAggregateInitialize(cs_ctx In Out strcat_type) Return Number, Member Function ODCIAggregateIterate(self In Out strcat_type,value in varchar2) Return Number, Member Function ODCIAggregateMerge(self In Out strcat_type,ctx2 In Out strcat_type) Return Number, Member Function ODCIAggregateTerminate(self In Out strcat_type,ReturnValue Out varchar2,flags in Number) Return Number ); / --2. 创建类型体 Create Or Replace Type Body Strcat_type Is Static Function ODCIAggregateInitialize( cs_ctx In Out strcat_type )Return Number is Begin cs_ctx := strcat_type( Null ); Return ODCIConst.Success; End; Member Function ODCIAggregateIterate( self In Out strcat_type, value In varchar2 ) Return Number is Begin if self.cat_string is Null or Instr( self.cat_string, value ) = 0 Then self.cat_string := self.cat_string || ','|| value; End if; Return ODCIConst.Success; End; Member Function ODCIAggregateTerminate( self In Out strcat_type, ReturnValue Out varchar2, flags In Number) Return Number is Begin ReturnValue := ltrim(rtrim( self.cat_string,','),',' ); Return ODCIConst.Success; End; Member Function ODCIAggregateMerge( self In Out strcat_type, ctx2 In Out strcat_type) Return Number is Begin if self.cat_string is Null or Instr( self.cat_string, ctx2.cat_string ) = 0 Then self.cat_string := self.cat_string || ',' || ctx2.cat_string; End if; Return ODCIConst.Success; End; End; / --3.创建函数: 使用聚合函数实现多行合并 Create or Replace Function f_StrCat( as_input Varchar2 ) Return Varchar2 PARALLEL_ENABLE AGGREGATE USING strcat_type; / Grant Execute on f_StrCat To Public; --End of 使用聚合函数实现多行合并 Create Or Replace Package UTL_INet AS Type VarChar_Type is Table of VarChar2(400) Index By Binary_Integer; Type Number_Type is Table of Number(12,4) Index By Binary_Integer; Type DynamicCursor is ref Cursor; --动态游标 --Purpose : 获得汉字拼音编码 Type ut_PYIndex_191_List is Varray( 191 ) OF Number; Type ut_PYIndex_List is Varray( 10 ) OF ut_PYIndex_191_List; is_OracleDirectory Constant VarChar2(20) := 'ATTACH_DIR'; --内部附件生成目录（Oracle的目录） --Clob叠加比较慢，先用VarChar2叠加到4000个字符后才叠加到Clob字段 --UTL_INet.p_ClobCAT( Procedure p_ClobCAT( ac_HTMLText in Out Clob, as_CatText in Out VarChar2, as_Str in VarChar2 Default Null ); --字符串根据特定分隔符分来 --Select UTL_INet.f_SplitString( 'A,B,C', xx, ',' ) From dual; Function f_SplitString( as_SourStr in out Clob, --输入字符串A,B,C as_Separator in VarChar2 Default '/' --分拆依据的分隔符, )Return VarChar2; --分拆结果A --将Clob内容写入物理文件 --Exec UTL_INet.p_PutClob2File( as_FileName => 'aa.sql', ac_Text => 'test sql' ); Procedure p_PutClob2File( as_SubDir in VarChar2, --目录名 as_FileName in VarChar2, --文件名 ac_Text in Clob, --文件内容 as_Overwrite in VarChar default 'Y', --标志位：Y:覆盖文件内容，N:追加 as_OraVersion in VarChar default 'N' --标志位：Y:写入Oracle版本信息 ); --序号自动递增计算 --e.g.: 输入：HLXU99349021，返回：HLXU99349022 --范例： Select UTL_INet.f_AutoNum( 'HLXU99349021' ), UTL_INet.f_AutoNum( 'ABA', -1 ), UTL_INet.f_AutoNum( 'ABZ' ) from Dual; Function f_AutoNum( as_OldNum in VarChar2, --原字符串 ai_Step in Number Default 1, --步长，默认是递增加1， ai_DigitXXX in Number Default Null --累计序号位数 XXX )Return VarChar2; --字符串加解密，返回一串32位长的字符串 --Select UTL_INet.f_MD5( 'TestPassword' ) From Dual; Function f_MD5( as_SourceStr in Varchar2 --需要加密的字符串 ) Return Varchar2; --将Email地址去头去尾，剩下最简单的Email地址，如"TSI Customer Service" 变成cs@csdn.com Function f_GetNakedEmailAddr( as_DisplayEmail In VarChar2, as_Including in Char Default 'N' --Y: 返回 )Return VarChar2; --测试发送Email的邮箱是否正确 Function f_TestEmailAccount( ac_Connection out Nocopy UTL_SMTP.Connection, as_SMTPHost in VarChar2, --邮件服务器 mail.csdn.com ai_SMTPPort in PLS_Integer Default 25, --邮件服务器端口 as_SMTPAuth in VarChar2 Default 'Y', --发送密码验证 as_Username in VarChar2 Default Null, --邮件用户 as_Password in VarChar2 Default Null, --邮件口令 as_WalletPath in VarChar2 Default Null, as_WalletPwd in VarChar2 Default Null )Return Boolean; ------------------------------------------------ 写邮件头和邮件内容------------------------- Procedure p_WriteRawData( ac_Conn in Out Nocopy UTL_SMTP.Connection, as_Partname in VarChar2, as_Value in VarChar2, as_Splite in VarChar2 Default ':', as_CRLF in VarChar2 Default UTL_TCP.CRLF ); ----------------------------------------------发送附件------------------------------------- Procedure p_MailAttachment( ac_Conn in Out Nocopy UTL_SMTP.Connection, as_Filename in VarChar2, as_Boundary in VarChar2, as_Encode in VarChar2 Default 'base64', as_MimeType in VarChar2 Default 'text/plain', as_ContentID in VarChar2 Default Null, -- ab_Inline in Boolean Default False --True将文本内容直接在邮件内容显示出来，并出现在附件中，False不显示只出现在附件中 ); -----------------自动签名的生成，签名生成显示后还出现此签名文件为附件，尚未解决------------------------------- Procedure p_GetMailSignature( ac_Conn in Out Nocopy UTL_SMTP.Connection, as_Boundary in VarChar2, as_Encode in VarChar2 Default 'base64', as_SignatureLogo in VarChar2 Default Null, as_SignatureText in VarChar2 Default Null ); --发送Email前必须将ewallet.p12拷贝到C:\OracleAttachDir目录 --发送电子邮件 --Exec UTL_INet.p_SendEmail( 'csdn@gmail.com', 'Test 主题Subject', 'Mail body(邮件内容)' ); Procedure p_SendEmail( as_Sender in VarChar2, as_Recipient in VarChar2, as_CC in VarChar2 Default Null, as_BCC in VarChar2 Default Null, as_Subject in VarChar2, ac_Message in Clob, as_AttachLists in VarChar2 Default Null, --多个用逗号，分开 as_SMTPHost in VarChar2, --邮件服务器 ai_SMTPPort in PLS_Integer Default 25, --邮件服务器端口 as_SMTPAuth in VarChar2 Default 'Y', --发送密码验证 as_WalletPath in VarChar2 Default Null, as_WalletPwd in VarChar2 Default Null, as_Username in VarChar2 Default Null, as_Password in VarChar2 Default Null, as_RunResult out VarChar2, --返回信息，OK成功，其他返回错误 as_SignatureLogo in VarChar2 Default Null, as_SignatureText in VarChar2 Default Null, as_Encode in VarChar2 Default 'base64', ai_Priority In Pls_Integer Default Null ); Function f_LoadHTMLFromURL( as_URL in VarChar2, as_CharSet in VarChar2 Default 'UTF-8' )Return Clob; --生成HTML报表表头 --Exec f_HTMLTableHead( 'Tab1', '20:Table Name;20:Records' ); Function f_HTMLTableHead( as_TableID in VarChar2, --表ID as_WidthColumns in VarChar2, --表头内容，用分号;隔开，宽度与标题用冒号:隔开 as_BgColor in VarChar2 Default 'CCCCCC' --标题背景色 )Return VarChar2; --生成HTML报表主体内容 --Exec UTL_INet.f_HTMLTableBody( '' ); Function f_HTMLTableBody( as_BodyText in VarChar2, --主体内容，多个用分号;隔开 as_Align in VarChar2 Default Null --格式（居中，靠左，靠右） )Return VarChar2; --获取汉字拼音字母表 --Select UTL_INet.f_getChineseSpell( '获取汉字拼音' ) from dual; Function f_getChineseSpell( as_CNStr in VarChar2, --中文 as_First in VarChar2 Default Null --空返回完整拼音，其他返回拼音首字母 )Return VarChar2; --二进制转换成十进制函数 --Select UTL_INet.f_Bin2Dec( '10111011' ) From dual; Function f_Bin2Dec( as_Bin in VarChar2 )Return Number; --十进制转换成二进制函数 --Select UTL_INet.f_Dec2Bin( 187 ) From dual; Function f_Dec2Bin( an_Dec in Number )Return VarChar2; --十进制转换成三十二进制函数 --Select UTL_INet.f_Dec2Hex( 187 ) From dual; Function f_Dec2Hex( an_Dec in Number )Return VarChar2; --三十二进制转换成十进制函数 --Select UTL_INet.f_Hex2Dec( '5R' ) From dual; Function f_Hex2Dec( as_Hex in VarChar2 )Return Number; --生成12位随机数 --Select UTL_INet.f_Rand() From dual; Function f_Rand( as_PreFix in VarChar2 Default '00', --未满个数字符补充串 an_Nums in Number Default 12 )Return VarChar2; --繁体字转化成简体字(传入的汉字，若有繁体自动转化为简体) Function f_ft2jt( as_Text in VarChar2 --传入的汉字 )Return VarChar2; --简体字转化成繁体字(传入的汉字，若有简体自动转化为繁体) Function f_jt2ft( as_Text in VarChar2 --传入的汉字 )Return VarChar2; -- -------------------------------------------------------------------------- -- Description : SOAP related Functions for consuming web services. Type t_Request is Record ( Method VarChar2(256), Namespace VarChar2(256), Body VarChar2(32767), EnvelopeTag VarChar2(30) ); Type t_Response is Record ( Doc XMLType, EnvelopeTag VarChar2(30) ); Function f_NewRequest( as_Method in VarChar2, as_Namespace in VarChar2, as_EnvelopeTag in VarChar2 Default 'SOAP-ENV' )Return t_Request; Procedure p_AddParameter( as_Request in out Nocopy t_Request, as_Name in VarChar2, as_Type in VarChar2, as_Value in VarChar2 ); Function f_Invoke( as_Request in out Nocopy t_Request, as_URL in VarChar2, as_Action in VarChar2 )Return t_Response; Function f_GetReturnValue( as_Response in out Nocopy t_Response, as_Name in VarChar2, as_Namespace in VarChar2 )Return VarChar2; --列出当前目录下所有文件清单，可以指定扩展名，是否包含子目录，返回的文件名用|分割开来 Function f_ListDirectory( as_SubDir in VarChar2, as_Ext in VarChar2 Default Null, as_IncludingSubDir in Char Default 'N' )Return Clob; --将数值翻译成中文大写、英文大写 --Select f_Digit2Char( 24822.80, 'EN_Amount' ) From dual; Function f_Digit2Char( an_Amount in Number, --要被翻译的数值 as_Option in VarChar2 --翻译选择项 )Return VarChar2; --发送短信 Function f_SendSMS( as_MobilePhone in VarChar2, --手机号码 as_SMSText in VarChar2, --短信内容 as_SMSURL in VarChar2, as_SMSUserID in VarChar2, as_SMSPasswd in VarChar2 )Return VarChar2; --删除某个指定文件 Procedure p_RemoveFile( as_SubDir in VarChar2, --路径 as_FileName in VarChar2 --多个用逗号，分开 ); --从文件中读内容 Function f_GetTextFromFile( as_SubDir in VarChar2, --目录名 as_FileName in VarChar2, --文件名 as_NewLine in VarChar2 Default UTL_TCP.CRLF --换行符 )Return Clob; END UTL_INet; /

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