DB2 - Problem description
| Problem IC74565 | Status: Closed |
DB2 might abend while creating MQT whose definition is recursive and has common table expression as well as IN predicate | |
| product: | |
DB2 FOR LUW / DB2FORLUW / 910 - DB2 | |
| Problem description: | |
MQT creation might trap with infinite recursive calls of
sqlnq_reroutable_ast_rec in the trap file. This happens only
when MQT definition has the following characteristics:
1. MQT definition has CSE (Common Sub Expression), called V1
2. MQT has recursive UNION ALL construct, called V2. V2 has two
union all branches. The first union branch references V1 and the
second branch references V1 and V2 of course.
3. V2 second branch has IN predicate and the element list
consists of multiple values or expressions.
Example:
-- create a base table
create table t1(c1 int, c2 int);
-- mqt creation traps
create table mqt as (
with v1(c1, c2) as (select * from t1),
v2(level, c1, c2) as (select 1, v1.* from v1 union all
select parent.level+1,
parent.c1, parent.c2 from v2 parent, v1 child
where parent.c1 = child.c1 and
child.c2 in (1,2) and parent.level < 10)
select c1, c2 from v2
) data initially deferred refresh deferred; | |
| Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * See error description above. * **************************************************************** * RECOMMENDATION: * * Upgrade to DB2 Version 9.1 Fix Pack 11. * **************************************************************** | |
| Local Fix: | |
Make V1 a regular view and change MQT definition to reference V1 instead of common table expression. | |
| available fix packs: | |
DB2 Version 9.1 Fix Pack 11 for Linux, UNIX and Windows | |
| Solution | |
First fixed in DB2 Version 9.1 Fix Pack 11. | |
| Workaround | |
not known / see Local fix | |
| BUG-Tracking | |
forerunner : APAR is sysrouted TO one or more of the following: IC78347 IC78348 follow-up : | |
| Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 18.02.2011 08.12.2011 08.12.2011 |
| Problem solved at the following versions (IBM BugInfos) | |
9.1.FP11 | |
| Problem solved according to the fixlist(s) of the following version(s) | |
| 9.1.0.11 |
|