Comments on: Index Scan with Filter Predicate Based on a Subquery http://www.antognini.ch/2012/02/index-scan-with-filter-predicate-based-on-a-subquery/ Tue, 18 Jun 2013 12:28:15 +0000 hourly 1 By: SQLTXPLAIN: Execution plan and operation order : Exec Ord column | Mohamed Houri’s Oracle Notes http://www.antognini.ch/2012/02/index-scan-with-filter-predicate-based-on-a-subquery/#comment-2190 SQLTXPLAIN: Execution plan and operation order : Exec Ord column | Mohamed Houri’s Oracle Notes Thu, 13 Jun 2013 10:01:40 +0000 http://antognini.ch/?p=1705#comment-2190 [...] rule is not applicable. Among those cases, I know two :  the  “constant subquery” and index scan with a filter predicate applying a subquery 0.000000 0.000000 Share this:EmailPrintLike this:Like Loading... Leave a [...] [...] rule is not applicable. Among those cases, I know two :  the  “constant subquery” and index scan with a filter predicate applying a subquery 0.000000 0.000000 Share this:EmailPrintLike this:Like Loading… Leave a [...]

]]> By: Missing Filter « Oracle Scratchpad http://www.antognini.ch/2012/02/index-scan-with-filter-predicate-based-on-a-subquery/#comment-522 Missing Filter « Oracle Scratchpad Wed, 29 Feb 2012 21:31:20 +0000 http://antognini.ch/?p=1705#comment-522 [...] interesting little defect in Enterprise Manager a little while ago - it doesn’t always know how to interpret execution plans. The problem appears in Christians’ example when a filter subquery predicate is applied [...] [...] interesting little defect in Enterprise Manager a little while ago - it doesn’t always know how to interpret execution plans. The problem appears in Christians’ example when a filter subquery predicate is applied [...]

]]> By: Christian Antognini http://www.antognini.ch/2012/02/index-scan-with-filter-predicate-based-on-a-subquery/#comment-521 Christian Antognini Sun, 26 Feb 2012 18:50:00 +0000 http://antognini.ch/?p=1705#comment-521 Hi Mohamed Runtime statistics generated with gather_plan_statistics are based on sampling. Hence, they are not always accurate. HTH Chris Hi Mohamed

Runtime statistics generated with gather_plan_statistics are based on sampling. Hence, they are not always accurate.

HTH
Chris

]]> By: Mohamed Houri http://www.antognini.ch/2012/02/index-scan-with-filter-predicate-based-on-a-subquery/#comment-520 Mohamed Houri Sun, 26 Feb 2012 16:38:06 +0000 http://antognini.ch/?p=1705#comment-520 Hi Christian, Thanks a lot for this precision. From now and on I will make attention to explain plans showing an index scan with both access and filter predicate applying a subquery. I often also see explain plans showing a A-Time of the parent operation being less than the sum of A-Time of its corresponding child operations as for example in the following example taken from an otn thread <pre>TABLE ACCESS BY INDEX ROWID | OE_ORDER_HEADERS_ALL | 1075 | 6485 | 16M|00:12:38.97 | INDEX RANGE SCAN | OE_ORDER_HEADER_ALL_ORG_ID_NDX | 1075 | 141K| 394M|00:19:52.50 |</pre> https://forums.oracle.com/forums/thread.jspa?messageID=10167734&#10167734 How could this be possible ? Best Regards Mohamed Houri Hi Christian,
Thanks a lot for this precision. From now and on I will make attention to explain plans showing an index scan with both access and filter predicate applying a subquery.

I often also see explain plans showing a A-Time of the parent operation being less than the sum of A-Time of its corresponding child operations as for example in the following example taken from an otn thread

TABLE ACCESS BY INDEX ROWID     | OE_ORDER_HEADERS_ALL           |   1075 |   6485 |     16M|00:12:38.97 |
 INDEX RANGE SCAN               | OE_ORDER_HEADER_ALL_ORG_ID_NDX |   1075 |    141K|    394M|00:19:52.50 |

https://forums.oracle.com/forums/thread.jspa?messageID=10167734&#10167734

How could this be possible ?

Best Regards

Mohamed Houri

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