Query Creating DB Bottlenecks

Question

Hi All,
I am facing performance issue with below query :
Select RequestResponseID, SORequestXml, SOPriority, SODelay, SOType, TRANSACTIONID from BATCH_REQUEST_RESPONSE  where ACKREC='N' and SOState='Created' and SourceAgentId=? and BatchUId in (select BatchUId from BATCH_METRICS where RequestSubmissionStatus='Completed' and OutputGenerationStatus <> 'Completed')and ROWNUM <= 5000  ORDER BY RequestResponseID
Here is the points of consideration.
In the table BATCH_REQUEST_RESPONSE  we have around 7 million records each having 3 fields (RowValue, SORequestXml and SOResponseXml) are of BLOB data type.
We have indexing on the column BatchUId. BATCH_REQUEST_RESPONSE   table has following indexex.
CREATE INDEX
MetricsResultIndx  ON BATCH_REQUEST_RESPONSE (BatchUId, SourceAgentId, BatchEnvName).
CREATE UNIQUE INDEX TransactionIdIndx ON BATCH_REQUEST_RESPONSE (TransactionId);
In the table BATCH_METRICS we have around 1000 records.
AWR report shows this query on top in terms of execution, physical reads, cpu time etc.
Please help us in providing the solution to make this query performance better.

Answer 1

Hi ,
PFB the execution plan:
PLAN_TABLE_OUTPUT
Plan hash value: 1765530150
| Id  | Operation | Name | Rows  | Bytes |TempSpc| Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT | |  5000 |   981K|       | 2448   (1)| 00:00:30 |
|   1 |  SORT ORDER BY | |  5000 |   981K|  2064K|  2448   (1)| 00:00:30 |
|*  2 |   COUNT STOPKEY | |       | | | |          |
|   3 |    NESTED LOOPS | |       | | | |          |
|   4 |     NESTED LOOPS | |  8981 |  1762K|       | 2050   (1)| 00:00:25 |
|*  5 | TABLE ACCESS FULL         | BATCH_METRICS |    52 |  1352 |       | 5   (0)| 00:00:01 |
PLAN_TABLE_OUTPUT
|*  6 | INDEX RANGE SCAN          | METRICSRESULTINDX      |  2422 |       |       | 1   (0)| 00:00:01 |
|*  7 |     TABLE ACCESS BY INDEX ROWID| BATCH_REQUEST_RESPONSE |   172 | 30100 |       |    39   (0)| 00:00:01 |
Predicate Information (identified by operation id):
   2 - filter(ROWNUM<=5000)
   5 - filter("OUTPUTGENERATIONSTATUS"<>'Completed' AND "REQUESTSUBMISSIONSTATUS"='Completed')
   6 - access("BATCHUID"="BATCHUID" AND "SOURCEAGENTID"='BA_PORT3RD')
   7 - filter("ACKREC"='N' AND "SOSTATE"='Created')
BATCH_METRICS we have around 1000 records and BATCH_REQUEST_RESPONSE has around 5 million records.
Please find the query again:
Select RequestResponseID, SORequestXml, SOPriority, SODelay, SOType, TRANSACTIONID fromBATCH_REQUEST_RESPONSE where ACKREC='N' and SOState='Created' and SourceAgentId='BA_PORT3RD' and BatchUId in (select BatchUId from BATCH_METRICS where RequestSubmissionStatus='Completed' and OutputGenerationStatus <> 'Completed')and ROWNUM <= 5000 ORDER BY RequestResponseID
Regards,
Unmesh