Re: [HACKERS] Should pg_export_snapshot() and currtid() be tagged parallel-unsafe?

[Robert Haas]

On Tue, Jun 14, 2016 at 5:01 PM, Andreas Seltenreich  wrote:
> Digging through the sqlsmith logging db, I noticed the following errors:
>
> ERROR:  cannot update SecondarySnapshot during a parallel operation
> ERROR:  cannot assign XIDs during a parallel operation
>
> Queries raising the first one always contain calls to currtid() or
> currtid2().  Queries raising the second one always contain a call to
> pg_export_snapshot().  Patch to tag them as unsafe attached.

Thanks, committed.

None of these are exercised by 'make check', or this would have been
caught sooner.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


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[HACKERS] Should pg_export_snapshot() and currtid() be tagged parallel-unsafe?

[Andreas Seltenreich]

Digging through the sqlsmith logging db, I noticed the following errors:

ERROR:  cannot update SecondarySnapshot during a parallel operation
ERROR:  cannot assign XIDs during a parallel operation

Queries raising the first one always contain calls to currtid() or
currtid2().  Queries raising the second one always contain a call to
pg_export_snapshot().  Patch to tag them as unsafe attached.

regards,
Andreas
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index f33c3ff..6a65e77 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -1347,9 +1347,9 @@ DATA(insert OID = 1291 (  suppress_redundant_updates_trigger	PGNSP PGUID 12 1 0
 DESCR("trigger to suppress updates when new and old records match");
 
 DATA(insert OID = 1292 ( tideq			   PGNSP PGUID 12 1 0 0 0 f f f t t f i s 2 0 16 "27 27" _null_ _null_ _null_ _null_ _null_ tideq _null_ _null_ _null_ ));
-DATA(insert OID = 1293 ( currtid		   PGNSP PGUID 12 1 0 0 0 f f f f t f v s 2 0 27 "26 27" _null_ _null_ _null_ _null_ _null_ currtid_byreloid _null_ _null_ _null_ ));
+DATA(insert OID = 1293 ( currtid		   PGNSP PGUID 12 1 0 0 0 f f f f t f v u 2 0 27 "26 27" _null_ _null_ _null_ _null_ _null_ currtid_byreloid _null_ _null_ _null_ ));
 DESCR("latest tid of a tuple");
-DATA(insert OID = 1294 ( currtid2		   PGNSP PGUID 12 1 0 0 0 f f f f t f v s 2 0 27 "25 27" _null_ _null_ _null_ _null_ _null_ currtid_byrelname _null_ _null_ _null_ ));
+DATA(insert OID = 1294 ( currtid2		   PGNSP PGUID 12 1 0 0 0 f f f f t f v u 2 0 27 "25 27" _null_ _null_ _null_ _null_ _null_ currtid_byrelname _null_ _null_ _null_ ));
 DESCR("latest tid of a tuple");
 DATA(insert OID = 1265 ( tidne			   PGNSP PGUID 12 1 0 0 0 f f f t t f i s 2 0 16 "27 27" _null_ _null_ _null_ _null_ _null_ tidne _null_ _null_ _null_ ));
 DATA(insert OID = 2790 ( tidgt			   PGNSP PGUID 12 1 0 0 0 f f f t t f i s 2 0 16 "27 27" _null_ _null_ _null_ _null_ _null_ tidgt _null_ _null_ _null_ ));
@@ -3135,7 +3135,7 @@ DESCR("xlog filename, given an xlog location");
 DATA(insert OID = 3165 ( pg_xlog_location_diff		PGNSP PGUID 12 1 0 0 0 f f f f t f i s 2 0 1700 "3220 3220" _null_ _null_ _null_ _null_ _null_ pg_xlog_location_diff _null_ _null_ _null_ ));
 DESCR("difference in bytes, given two xlog locations");
 
-DATA(insert OID = 3809 ( pg_export_snapshot		PGNSP PGUID 12 1 0 0 0 f f f f t f v r 0 0 25 "" _null_ _null_ _null_ _null_ _null_ pg_export_snapshot _null_ _null_ _null_ ));
+DATA(insert OID = 3809 ( pg_export_snapshot		PGNSP PGUID 12 1 0 0 0 f f f f t f v u 0 0 25 "" _null_ _null_ _null_ _null_ _null_ pg_export_snapshot _null_ _null_ _null_ ));
 DESCR("export a snapshot");
 
 DATA(insert OID = 3810 (  pg_is_in_recovery		PGNSP PGUID 12 1 0 0 0 f f f f t f v s 0 0 16 "" _null_ _null_ _null_ _null_ _null_ pg_is_in_recovery _null_ _null_ _null_ ));

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