--1719

SESSION_ID  1141  
SQL_ID   drpk7cccd9xhm  
MACHINE  WORKGROUP\TLCB-PC 
BLOCKING_SESSION     
SAMPLE_TIME 10-4月 -19 07.50.01.154 下午  
MODULE   PL/SQL Developer  
PROGRAM  plsqldev.exe   
EVENT db file sequential read 
P1 4  
P1TEXT   file# 
P2 190469   
P2TEXT   block#   
P3 1  
P3TEXT   blocks   
SQL_TEXT select count(*) from p800 where owner='SCOTT'   



SQL> select owner,segment_name,segment_type,partition_name from dba_extents where file_id=4 and 190469  between block_id and block_id+blocks-1;

OWNER    SEGMENT_NAME        SEGMENT_TYPE        PARTITION_NAME
---------- ------------------------------ ------------------------------ ------------------------------------------------------------------------------------------
TEST     P800_IDX2           INDEX


SQL> explain plan for select count(*) from p800 where owner='SCOTT'  ;

已解释。

SQL> select * from table(dbms_xplan.display());

PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Plan hash value: 3042126352

-------------------------------------------------------------------------------
| Id  | Operation   | Name      | Rows  | Bytes | Cost (%CPU)| Time     |
-------------------------------------------------------------------------------
|   0 | SELECT STATEMENT  |         |     1 |    17 |     5 (0)| 00:00:01 |
|   1 |  SORT AGGREGATE   |         |     1 |    17 |       |        |
|*  2 |   INDEX RANGE SCAN| P800_IDX2 |   874 | 14858 |     5  (0)| 00:00:01 |
-------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   2 - access("OWNER"='SCOTT')

Note
-----
   - dynamic sampling used for this statement (level=2)

已选择18行。