测试使用hr用户下的employees表写一条SQL语句,执行计划走索引全扫描
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SQL> select count(*) from employees;
COUNT(*)
----------
107
Execution Plan
----------------------------------------------------------
Plan hash value: 3580537945
-------------------------------------------------------------------------
| Id | Operation | Name | Rows | Cost (%CPU)| Time |
-------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 1 | 1 (0)| 00:00:01 |
| 1 | SORT AGGREGATE | | 1 | | |
| 2 | INDEX FULL SCAN| EMP_EMAIL_UK | 107 | 1 (0)| 00:00:01 |
-------------------------------------------------------------------------
Statistics
----------------------------------------------------------
224 recursive calls
0 db block gets
180 consistent gets
1 physical reads
0 redo size
527 bytes sent via SQL*Net to client
523 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
6 sorts (memory)
0 sorts (disk)
1 rows processed
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