|
Problem IC70245
|
Status: Closed |
VISUAL EXPLAIN CRASHES WHEN ACCESS PLAN CONTAINS AN ISCAN. |
| product: |
DB2 FOR LUW / DB2FORLUW / 910 - DB2 |
| Problem description: |
When we try to get the access plan from Visual Explain for a
query that contains an IXSCAN, Visual Explain crashes. An
example of a simple query that exhibits this behaviour is:
SELECT POLICY FROM SYSTOOLS.POLICY
Using Visual Explain, the client v9x talks to the server
instance v91 fp9, and Visual Explain crashes.
You can verify if you are encountering this problem by obtaining
a db2exfmt explain of the query:
1) ensure the explain tables have been created, if not
previously used:
- connect to the database, and use "db2 -tvf
sqllib/misc/EXPLAIN.DDL"
2) connect to the database, and generate the explain for the
query using the explain statement:
- explain plan for ...sql_statement...
- where "...sql_statement..." is replaced by the sql statement
that you want to check.
3) use the db2exfmt utility to format the generated plan:
- db2exfmt -d ...db_name... -1 -o check_plan.exfmt
- where "...db_name..." is replaced with the database name. If
password authentication is needed, you may be prompted for a
userid and password.
4) edit or grep the explain format utility's out to determine if
there is an IXSCAN operator:
- grep IXSCAN check_plan.exfmt
5) If the above check indicates there is one or more IXSCAN
operators found in the explain, then you have encountered this
APAR. |
| Problem Summary: |
****************************************************************
* USERS AFFECTED: *
* All DB2 LUW users of Visual Explain *
****************************************************************
* PROBLEM DESCRIPTION: *
* When we try to get the access plan from Visual Explain for a *
* *
* query that contains an IXSCAN, Visual Explain crashes. An *
* *
* example of a simple query that exhibits this behaviour is: *
* *
* *
* *
* SELECT POLICY FROM SYSTOOLS.POLICY *
* *
* *
* *
* Using Visual Explain, the client v9x talks to the server *
* *
* instance v91 fp9, and Visual Explain crashes. *
* *
* *
* *
* You can verify if you are encountering this problem by *
* obtaining *
* a db2exfmt explain of the query: *
* *
* 1) ensure the explain tables have been created, if not *
* *
* previously used: *
* *
* - connect to the database, and use "db2 -tvf *
* *
* sqllib/misc/EXPLAIN.DDL" *
* *
* 2) connect to the database, and generate the explain for the *
* *
* query using the explain statement: *
* *
* - explain plan for ...sql_statement... *
* *
* - where "...sql_statement..." is replaced by the sql *
* statement *
* that you want to check. *
* *
* 3) use the db2exfmt utility to format the generated plan: *
* *
* - db2exfmt -d ...db_name... -1 -o check_plan.exfmt *
* *
* - where "...db_name..." is replaced with the database *
* name. If *
* password authentication is needed, you may be prompted for a *
* *
* userid and password. *
* *
* 4) edit or grep the explain format utility's out to *
* determine if *
* there is an IXSCAN operator: *
* *
* - grep IXSCAN check_plan.exfmt *
* *
* 5) If the above check indicates there is one or more IXSCAN *
* *
* operators found in the explain, then you have encountered *
* this *
* APAR. *
****************************************************************
* RECOMMENDATION: *
* Apply the DB2 V9.1 Fix Pack 10 to the server. *
**************************************************************** |
| Local Fix: |
Use the db2exfmt utility, or the Optim tools (for DB2 V9.1 and
on), to obtain the explain instead of Visual Explain. |
| available fix packs: |
DB2 Version 9.1 Fix Pack 10 for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 11 for Linux, UNIX and Windows
DB2 Version 9.1 Fix Pack 12 for Linux, UNIX and Windows
|
| Solution |
The fix for this problem can be found in DB2 V9.1 Fix Pack 10. |
| Workaround |
Use db2exfmt, or the Optim Query Tuner tools. |
| BUG-Tracking |
forerunner : APAR is sysrouted TO one or more of the following: IC71119 IC71120 IC71121
follow-up : |
| Timestamps |
Date - problem reported :
Date - problem closed :
Date - last modified :
| 28.07.2010
20.06.2011
20.06.2011 |
| Problem solved at the following versions (IBM BugInfos) |
9.1.FP10
|
| Problem solved according to the fixlist(s) of the following version(s) |
| 9.1.0.10
|
 |
