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create table SYSTEM.AC_TEST
(
record_time TIMESTAMP(3) not null,
ac_1 FLOAT,
ac_2 FLOAT,
ac_3 FLOAT,
ac_4 FLOAT,
ac_5 FLOAT,
ac_6 FLOAT,
ac_7 FLOAT,
ac_8 FLOAT,
ac_9 FLOAT,
ac_10 FLOAT,
ac_11 FLOAT,
ac_12 FLOAT,
ac_13 FLOAT,
ac_14 FLOAT,
ac_15 FLOAT,
ac_16 FLOAT
);
alter table SYSTEM.AC_TEST
add constraint RECORD_DATE primary key (RECORD_TIME);
Select ac_1 From ac_test
Where record_time >= to_timestamp('2016-08-01 00:00:00', 'yyyy-mm-dd hh24:mi:ss')
And record_time <=to_timestamp('2016-08-01 00:30:00', 'yyyy-mm-dd hh24:mi:ss');
select sum( *) from
(select count(*) cn from t_table_SS PARTITION (P200709_1)
union all
select count(*) cn from t_table_SS PARTITION (P200709_2)
);
Plan Hash Value : 2937004892
------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost | Time |
------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 90001 | 31230347 | 4987 | 00:01:00 |
| 1 | TABLE ACCESS BY INDEX ROWID | AC_TEST | 90001 | 31230347 | 4987 | 00:01:00 |
| * 2 | INDEX RANGE SCAN | RECORD_DATE | 90001 | | 251 | 00:00:04 |
------------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
------------------------------------------
* 2 - access("RECORD_TIME">=TIMESTAMP' 2016-08-01 00:00:00.000000000' AND "RECORD_TIME"<=TIMESTAMP' 2016-08-01 00:30:00.000000000')
Plan Hash Value : 3955607741
--------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost | Time |
--------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 90001 | 2880032 | 33453 | 00:06:42 |
| 1 | TABLE ACCESS BY INDEX ROWID | AC_TEST | 90001 | 2880032 | 33453 | 00:06:42 |
| * 2 | INDEX RANGE SCAN | PK_TIME | 90001 | | 1936 | 00:00:24 |
--------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
------------------------------------------
* 2 - access("RECORD_TIME">=TIMESTAMP' 2016-08-01 00:00:00.000000000' AND "RECORD_TIME"<=TIMESTAMP' 2016-08-01 00:30:00.000000000')
看结果应该是走了索引的,只检索了30分钟的数据(50*60*30)。 帮忙看看是否是这样的