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Problem IC65262
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Status: Closed |
IMPROVE THE HANDLING OF CONVERSION TO NLJOIN FROM MULTIPLE IN PREDICATES |
| product: |
DB2 FOR LUW / DB2FORLUW / 950 - DB2 |
| Problem description: |
If a query WHERE clause contains more than one simple IN
predicates whose IN operand is base column and IN elements are
composed of only literals, DB2 query compiler can convert one of
them to NLJOIN. It is possible that the compiler converts a
suboptimal IN predicate rather than the optimal one. The fix
makes sure the converted IN predicate is the optimal one.
Local fix: Use optimizer profile option "<INLIST2JOIN
OPTION="ENABLE" TABLE="TABLE_NAME" COLUMN="COLUMN_NAME"/>.
Replace TABLE_NAME and COLUMN_NAME with the real name of the IN
predicate dedicated to DB2 compiler for attempting the IN to
NLJOIN conversion. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* V9.5 *
****************************************************************
* PROBLEM DESCRIPTION: *
* If a query WHERE clause contains more than one simple *
* INpredicates whose IN operand is base column and IN *
* elementsarecomposed of only literals, DB2 query compiler can *
* convertone ofthem to NLJOIN. It is possible that the *
* compiler converts asuboptimal IN predicate rather than the *
* optimal one. The fixmakes sure the converted IN predicate is *
* the optimal one.Local fix: Use optimizer profile option *
* "<INLIST2JOINOPTION="ENABLE" TABLE="TABLE_NAME" *
* COLUMN="COLUMN_NAME"/>.Replace TABLE_NAME and COLUMN_NAME *
* with the real name of theINpredicate dedicated to DB2 *
* compiler for attempting the IN toNLJOIN conversion. *
****************************************************************
* RECOMMENDATION: *
* Upgrade to Fix pack 6 *
**************************************************************** |
| Local Fix: |
|
| available fix packs: |
DB2 Version 9.5 Fix Pack 6a for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 7 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 8 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 9 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 10 for Linux, UNIX, and Windows
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| Solution |
|
| Workaround |
not known / see Local fix |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 21.12.2009
31.05.2010
31.05.2010 |
| Problem solved at the following versions (IBM BugInfos) |
|
| Problem solved according to the fixlist(s) of the following version(s) |
