2.filter --过滤,如not in、min函数等容易产生 Has a number of different meanings, used to indicate partition elimination, may also indicate an actual filter step where one row source is filtering, another, functions such as min may introduce filter steps into query plans. 3.view --视图,大都...
Introduced in 7.3 and requires V733_PLANS_ENABLED=TRUE and CBO, may be hinted using INDEX_FFS hint, uses multiblock i/o, can be executed in parallel, can be used to access second column of concatenated indexes. This is because we are selecting all of the index. ...
('plan_table',null,'typical -cost -bytes')); Figure 6: Customized TYPICAL plan with suppressed options COST and BYTES The Note Section In addition to the plan and the predicate information, the DBMS_XPLAN package displays additional information in the NOTE section, such as when dynamic ...
Operator ID is currently giving the physical operator ID as stored in the explain tables. It might be more appropriate to display a line number like the Oracle DBMS_XPLAN does so that it is more easy to find a specific ID. Indicate the presences of predicates with a asterisk next to the...
SQL> select * from table(dbms_xplan.display); PLAN_TABLE_OUTPUT --- --- Plan hash value: 2498281325 --- --- | Id | Operation | Name | Rows | Bytes | Cost (%CPU)| --
The statement in Example 12-4 displays the execution plans. Example 12-4 Statement to display the EXPLAIN PLAN SELECT PLAN_TABLE_OUTPUT FROM TABLE(DBMS_XPLAN.DISPLAY(NULL, 'statement_id','BASIC')); Examples of the output from this statement are shown in Example 12-5 and Example 12-6. ...
If you don't name the query blocks in a statement, Oracle will generate query block names for you. To see those names automatically, run an EXPLAIN PLAN on your statement followed by a query using the ALL option of DBMS_XPLAN.DISPLAY: ...
next level of the query for processing. In this case it is the SELECT STATEMENT which is the top of the query. [CHOOSE] is an indication of the optimizer_goal for the query. This DOES NOT necessarily indicate that plan has actually used this goal. The only way to ...
which is a hash join rowsource, and so on. Note that os_explain prefixes some lines with an asterisk (*), this indicates that the output of given function is in turn filtered by a filter operation (the same filter ops what you normally see in the bottom of DBMS...
1.setautotraceon2.explain planforsql语句;selectplan_table_outputfromtable(dbms_xplan.display());3.通过第3方工具,如plsql developer(f5查看执行计划)、toad等; 三、看懂执行计划 1.执行计划中字段解释 SQL> select * from scott.emp a,scott.emp b where a.empno=b.mgr; ...