diff options
Diffstat (limited to 'src/backend/access/heap/heapam.c')
| -rw-r--r-- | src/backend/access/heap/heapam.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index b504ccd05c3..e84c1743f4f 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -42,6 +42,7 @@ #include "access/heapam_xlog.h" #include "access/hio.h" #include "access/multixact.h" +#include "access/parallel.h" #include "access/relscan.h" #include "access/sysattr.h" #include "access/transam.h" @@ -1051,7 +1052,13 @@ relation_open(Oid relationId, LOCKMODE lockmode) /* Make note that we've accessed a temporary relation */ if (RelationUsesLocalBuffers(r)) + { + if (IsParallelWorker()) + ereport(ERROR, + (errcode(ERRCODE_INVALID_TRANSACTION_STATE), + errmsg("cannot access temporary tables during a parallel operation"))); MyXactAccessedTempRel = true; + } pgstat_initstats(r); @@ -1097,7 +1104,13 @@ try_relation_open(Oid relationId, LOCKMODE lockmode) /* Make note that we've accessed a temporary relation */ if (RelationUsesLocalBuffers(r)) + { + if (IsParallelWorker()) + ereport(ERROR, + (errcode(ERRCODE_INVALID_TRANSACTION_STATE), + errmsg("cannot access temporary tables during a parallel operation"))); MyXactAccessedTempRel = true; + } pgstat_initstats(r); @@ -2237,6 +2250,17 @@ static HeapTuple heap_prepare_insert(Relation relation, HeapTuple tup, TransactionId xid, CommandId cid, int options) { + /* + * For now, parallel operations are required to be strictly read-only. + * Unlike heap_update() and heap_delete(), an insert should never create + * a combo CID, so it might be possible to relax this restriction, but + * not without more thought and testing. + */ + if (IsInParallelMode()) + ereport(ERROR, + (errcode(ERRCODE_INVALID_TRANSACTION_STATE), + errmsg("cannot insert tuples during a parallel operation"))); + if (relation->rd_rel->relhasoids) { #ifdef NOT_USED @@ -2648,6 +2672,16 @@ heap_delete(Relation relation, ItemPointer tid, Assert(ItemPointerIsValid(tid)); + /* + * Forbid this during a parallel operation, lets it allocate a combocid. + * Other workers might need that combocid for visibility checks, and we + * have no provision for broadcasting it to them. + */ + if (IsInParallelMode()) + ereport(ERROR, + (errcode(ERRCODE_INVALID_TRANSACTION_STATE), + errmsg("cannot delete tuples during a parallel operation"))); + block = ItemPointerGetBlockNumber(tid); buffer = ReadBuffer(relation, block); page = BufferGetPage(buffer); @@ -3100,6 +3134,16 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup, Assert(ItemPointerIsValid(otid)); /* + * Forbid this during a parallel operation, lets it allocate a combocid. + * Other workers might need that combocid for visibility checks, and we + * have no provision for broadcasting it to them. + */ + if (IsInParallelMode()) + ereport(ERROR, + (errcode(ERRCODE_INVALID_TRANSACTION_STATE), + errmsg("cannot update tuples during a parallel operation"))); + + /* * Fetch the list of attributes to be checked for HOT update. This is * wasted effort if we fail to update or have to put the new tuple on a * different page. But we must compute the list before obtaining buffer @@ -5400,6 +5444,17 @@ heap_inplace_update(Relation relation, HeapTuple tuple) uint32 oldlen; uint32 newlen; + /* + * For now, parallel operations are required to be strictly read-only. + * Unlike a regular update, this should never create a combo CID, so it + * might be possible to relax this restriction, but not without more + * thought and testing. It's not clear that it would be useful, anyway. + */ + if (IsInParallelMode()) + ereport(ERROR, + (errcode(ERRCODE_INVALID_TRANSACTION_STATE), + errmsg("cannot update tuples during a parallel operation"))); + buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(&(tuple->t_self))); LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE); page = (Page) BufferGetPage(buffer); |