The Result Details section represents a drill-down into the performance of SQL statements that appears in the Result Summary section of the report. Use the information in this section to investigate why the performance of a particular SQL statement regressed.
This section will contain an entry of every SQL statement processed in the SQL performance impact analysis. Each entry is organized into the following subsections:
This section of the report summarizes the SQL statement, listing its information and execution details.
Example 6-5 shows the SQL Details subsection of a sample report.
In Example 6-5, the report summarizes the regressed SQL statement whose ID is 2wtgxbjz6u2by and corresponding object ID is 204.
SQL Details:
-----------------------------
Object ID : 204
Schema Name : APPS
SQL ID : 2wtgxbjz6u2by
Execution Frequency : 1
SQL Text : SELECT /* my_query_14_scott */ /*+ ORDERED INDEX(t1)
USE_HASH(t1) */ 'B' || t2.pg_featurevalue_05_id
pg_featurevalue_05_id, 'r' || t4.elementrange_id
pg_featurevalue_15_id, 'G' || t5.elementgroup_id
pg_featurevalue_01_id, 'r' || t6.elementrange_id . . .
.
.
.
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The Execution Statistics subsection compares execution statistics of the SQL statement from the pre-change and post-change executions and then summarizes the findings.
Example 6-6 shows the Execution Statistics subsection of a sample report.
Example 6-6 Execution Statistics
Execution Statistics: ----------------------------- --------------------------------------------------------------------------------------- | | Impact on | Value | Value | Impact | % Workload | % Workload | | Stat Name | Workload | Before | After | on SQL | Before | After | --------------------------------------------------------------------------------------- | elapsed_time | -95.54%| 36.484 | 143.161 | -292.39% | 32.68% | 94.73% | | parse_time | -12.37%| .004 | .062 | -1450% | .85% | 11.79% | | exec_elapsed | -95.89%| 36.48 | 143.099 | -292.27% | 32.81% | 95.02% | | exec_cpu | -19.73%| 36.467 | 58.345 | -59.99% | 32.89% | 88.58% | | buffer_gets | -10.08%| 1653012 | 2160529 | -30.7% | 32.82% | 82.48% | | cost | 12.17%| 11224 | 2771 | 75.31% | 16.16% | 4.66% | | reads | -1825.72%| 4091 | 455280 | -11028.82% | 16.55% | 96.66% | | writes | -1500%| 0 | 15 | -1500% | 0% | 100% | | rows | | 135 | 135 | | | | --------------------------------------------------------------------------------------- Notes: ----------------------------- Before Change: 1. The statement was first executed to warm the buffer cache. 2. Statistics shown were averaged over next 9 executions. After Change: 1. The statement was first executed to warm the buffer cache. 2. Statistics shown were averaged over next 9 executions. Findings (2): ----------------------------- 1. The performance of this SQL has regressed. 2. The structure of the SQL execution plan has changed. ---------------------------------------------------------------------------------------------
The Execution Plans subsection displays the pre-change and post-change execution plans for the SQL statement. In cases when the performance regressed, this section also contains findings on root causes and symptoms.
Example 6-7 shows the Execution Plans subsection of a sample report.
Execution Plan Before Change: ----------------------------- Plan Id : 1 Plan Hash Value : 3412943215 ---------------------------------------------------------------------------------------------------------- | Id | Operation | Name | Rows | Bytes | Cost | Time | ---------------------------------------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | 126 | 11224 | 00:02:15 | | 1 | HASH GROUP BY | | 1 | 126 | 11224 | 00:02:15 | | 2 | NESTED LOOPS | | 1 | 126 | 11223 | 00:02:15 | | * 3 | HASH JOIN | | 1 | 111 | 11175 | 00:02:15 | | * 4 | TABLE ACCESS FULL | LU_ELEMENTGROUP_REL | 1 | 11 | 162 | 00:00:02 | | * 5 | HASH JOIN | | 487 | 48700 | 11012 | 00:02:13 | | 6 | MERGE JOIN | | 14 | 924 | 1068 | 00:00:13 | | 7 | SORT JOIN | | 5391 | 274941 | 1033 | 00:00:13 | | * 8 | HASH JOIN | | 5391 | 274941 | 904 | 00:00:11 | | * 9 | TABLE ACCESS FULL | LU_ELEMENTGROUP_REL | 123 | 1353 | 175 | 00:00:03 | | * 10 | HASH JOIN | | 5352 | 214080 | 729 | 00:00:09 | | * 11 | TABLE ACCESS FULL | LU_ITEM_293 | 5355 | 128520 | 56 | 00:00:01 | | * 12 | TABLE ACCESS FULL | ADM_PG_FEATUREVALUE | 1629 | 26064 | 649 | 00:00:08 | | * 13 | FILTER | | | | | | | * 14 | SORT JOIN | | 1 | 15 | 36 | 00:00:01 | | * 15 | TABLE ACCESS FULL | LU_ELEMENTRANGE_REL | 1 | 15 | 35 | 00:00:01 | | 16 | INLIST ITERATOR | | | | | | | * 17 | TABLE ACCESS BY INDEX ROWID | FACT_PD_OUT_ITM_293 | 191837 | 6522458 | 9927 | 00:02:00 | | 18 | BITMAP CONVERSION TO ROWIDS | | | | | | | * 19 | BITMAP INDEX SINGLE VALUE | FACT_274_PER_IDX | | | | | | * 20 | TABLE ACCESS FULL | LU_ELEMENTRANGE_REL | 1 | 15 | 49 | 00:00:01 | ---------------------------------------------------------------------------------------------------------- . . . Execution Plan After Change: ----------------------------- Plan Id : 102 Plan Hash Value : 1923145679 ------------------------------------------------------------------------------------------------------ | Id | Operation | Name | Rows | Bytes | Cost | Time | ------------------------------------------------------------------------------------------------------ | 0 | SELECT STATEMENT | | 1 | 126 | 2771 | 00:00:34 | | 1 | HASH GROUP BY | | 1 | 126 | 2771 | 00:00:34 | | 2 | NESTED LOOPS | | 1 | 126 | 2770 | 00:00:34 | | * 3 | HASH JOIN | | 1 | 111 | 2722 | 00:00:33 | | * 4 | HASH JOIN | | 1 | 100 | 2547 | 00:00:31 | | * 5 | TABLE ACCESS FULL | LU_ELEMENTGROUP_REL | 1 | 11 | 162 | 00:00:02 | | 6 | NESTED LOOPS | | | | | | | 7 | NESTED LOOPS | | 484 | 43076 | 2384 | 00:00:29 | | * 8 | HASH JOIN | | 14 | 770 | 741 | 00:00:09 | | 9 | NESTED LOOPS | | 4 | 124 | 683 | 00:00:09 | | * 10 | TABLE ACCESS FULL | LU_ELEMENTRANGE_REL | 1 | 15 | 35 | 00:00:01 | | * 11 | TABLE ACCESS FULL | ADM_PG_FEATUREVALUE | 4 | 64 | 649 | 00:00:08 | | * 12 | TABLE ACCESS FULL | LU_ITEM_293 | 5355 | 128520 | 56 | 00:00:01 | | 13 | BITMAP CONVERSION TO ROWIDS | | | | | | | * 14 | BITMAP INDEX SINGLE VALUE | FACT_274_ITEM_IDX | | | | | | * 15 | TABLE ACCESS BY INDEX ROWID | FACT_PD_OUT_ITM_293 | 36 | 1224 | 2384 | 00:00:29 | | * 16 | TABLE ACCESS FULL | LU_ELEMENTGROUP_REL | 123 | 1353 | 175 | 00:00:03 | | * 17 | TABLE ACCESS FULL | LU_ELEMENTRANGE_REL | 1 | 15 | 49 | 00:00:01 | ------------------------------------------------------------------------------------------------------