segfault of autovacuum process during restore - coredumps included

L.S.

Since I started to use v8.1 I've been seeing incidental segfaults of the
autovacuum process, probably when it is kicking in at some particular point
during the pg_restore of a database:

<-2005-11-28 09:39:12 CET>LOG: autovacuum process (PID 5075) was terminated
by signal 11
<-2005-11-28 09:39:12 CET>LOG: terminating any other active server processes

and

<-2005-11-28 10:09:21 CET>LOG: autovacuum process (PID 5230) was terminated
by signal 11
<-2005-11-28 10:09:21 CET>LOG: terminating any other active server processes

Triggering it twice this morning annoyed me enough to recompile with debug
info/asserts. During a number of (20-30) additional 'tries' and I was able
to trigger the problem twice, resulting the following coredumps:

#0 0x082535fc in CopySnapshot (snapshot=0x0) at tqual.c:1301
1301 newsnap = (Snapshot) palloc(sizeof(SnapshotData) +
(gdb) where
#0 0x082535fc in CopySnapshot (snapshot=0x0) at tqual.c:1301
#1 0x0814673b in fmgr_sql (fcinfo=0xbfe9d740) at functions.c:319
#2 0x081400bc in ExecMakeFunctionResult (fcache=0x8517ab8,
econtext=0x8517f10, isNull=0xbfe9d9bb "�231=\b", isDone=0x0) at
execQual.c:1096
#3 0x081426d6 in ExecEvalExprSwitchContext (expression=0x8519b04,
econtext=0x0, isNull=0xbfe9d9bb "�231=\b", isDone=0x0) at execQual.c:2865
#4 0x08189e53 in evaluate_expr (expr=0x8517ab8, result_type=23) at
clauses.c:2646
#5 0x0818b8e9 in simplify_function (funcid=163843, result_type=23,
args=0x85023c0, allow_inline=1 '\001', context=0xbfe9dbd0) at clauses.c:2260
#6 0x0818bdea in eval_const_expressions_mutator (node=0x8502144,
context=0xbfe9dbd0) at clauses.c:1305
#7 0x0818a5bd in expression_tree_mutator (node=0x85015a0, mutator=0x818bc10
<eval_const_expressions_mutator>, context=0xbfe9dbd0) at clauses.c:3473
#8 0x0818be4d in eval_const_expressions_mutator (node=0x8501694,
context=0xbfe9dbd0) at clauses.c:1335
#9 0x0818c431 in eval_const_expressions_mutator (node=0x8502304,
context=0xbfe9dbd0) at clauses.c:2030
#10 0x0818ca35 in eval_const_expressions (node=0x85016c0) at clauses.c:1211
#11 0x0822fd63 in RelationGetIndexPredicate (relation=0x443361b8) at
relcache.c:2790
#12 0x080cb49f in BuildIndexInfo (index=0x443361b8) at index.c:900
#13 0x080febd6 in analyze_rel (relid=164956, vacstmt=0x44217764) at
analyze.c:257
#14 0x0813728b in vacuum (vacstmt=0x44217764, relids=0x44219fb8) at
vacuum.c:476
#15 0x0819350f in autovacuum_do_vac_analyze (relids=0x4421b394, dovacuum=0
'\0', doanalyze=1 '\001', freeze=0 '\0') at autovacuum.c:900
#16 0x08193ead in AutoVacMain (argc=0, argv=0x0) at autovacuum.c:674
#17 0x081941f6 in autovac_start () at autovacuum.c:170
#18 0x08199f91 in ServerLoop () at postmaster.c:1268
#19 0x0819b122 in PostmasterMain (argc=3, argv=0x833b8b8) at postmaster.c:943
#20 0x0815bece in main (argc=3, argv=0x833b8b8) at main.c:256

and

#0 0x082535fc in CopySnapshot (snapshot=0x0) at tqual.c:1301
1301 newsnap = (Snapshot) palloc(sizeof(SnapshotData) +
(gdb) bt
#0 0x082535fc in CopySnapshot (snapshot=0x0) at tqual.c:1301
#1 0x0814673b in fmgr_sql (fcinfo=0xbfd97090) at functions.c:319
#2 0x081400bc in ExecMakeFunctionResult (fcache=0x8567a50,
econtext=0x8567ea8, isNull=0xbfd9730b "", isDone=0x0) at execQual.c:1096
#3 0x081426d6 in ExecEvalExprSwitchContext (expression=0x8569a9c,
econtext=0x0, isNull=0xbfd9730b "", isDone=0x0) at execQual.c:2865
#4 0x08189e53 in evaluate_expr (expr=0x8567a50, result_type=23) at
clauses.c:2646
#5 0x0818b8e9 in simplify_function (funcid=226356, result_type=23,
args=0x8552278, allow_inline=1 '\001', context=0xbfd97520) at clauses.c:2260
#6 0x0818bdea in eval_const_expressions_mutator (node=0x8551ffc,
context=0xbfd97520) at clauses.c:1305
#7 0x0818a5bd in expression_tree_mutator (node=0x853d450, mutator=0x818bc10
<eval_const_expressions_mutator>, context=0xbfd97520) at clauses.c:3473
#8 0x0818be4d in eval_const_expressions_mutator (node=0x853d544,
context=0xbfd97520) at clauses.c:1335
#9 0x0818c431 in eval_const_expressions_mutator (node=0x85521bc,
context=0xbfd97520) at clauses.c:2030
#10 0x0818ca35 in eval_const_expressions (node=0x853d570) at clauses.c:1211
#11 0x0822fd63 in RelationGetIndexPredicate (relation=0x44377818) at
relcache.c:2790
#12 0x080cb49f in BuildIndexInfo (index=0x44377818) at index.c:900
#13 0x080febd6 in analyze_rel (relid=227469, vacstmt=0x44258764) at
analyze.c:257
#14 0x0813728b in vacuum (vacstmt=0x44258764, relids=0x4425afb8) at
vacuum.c:476
#15 0x0819350f in autovacuum_do_vac_analyze (relids=0x4425c394, dovacuum=0
'\0', doanalyze=1 '\001', freeze=0 '\0') at autovacuum.c:900
#16 0x08193ead in AutoVacMain (argc=0, argv=0x0) at autovacuum.c:674
#17 0x081941f6 in autovac_start () at autovacuum.c:170
#18 0x08199f91 in ServerLoop () at postmaster.c:1268
#19 0x0819b122 in PostmasterMain (argc=3, argv=0x833b8b8) at postmaster.c:943
#20 0x0815bece in main (argc=3, argv=0x833b8b8) at main.c:256

Both dumps are still available for additional info on variable-values, etc.

db=# select version();
version
------------------------------------------------------------------------
PostgreSQL 8.1.0 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.4.3

--
Best,

Frank.