diff options
Diffstat (limited to 'src/backend/executor/nodeModifyTable.c')
| -rw-r--r-- | src/backend/executor/nodeModifyTable.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c index 8c0f3126058..bfdf015f913 100644 --- a/src/backend/executor/nodeModifyTable.c +++ b/src/backend/executor/nodeModifyTable.c @@ -1199,6 +1199,7 @@ ExecUpdate(ModifyTableState *mtstate, } else { + ItemPointerData lockedtid PG_USED_FOR_ASSERTS_ONLY; LockTupleMode lockmode; bool partition_constraint_failed; bool update_indexes; @@ -1390,6 +1391,26 @@ lreplace: ExecConstraints(resultRelInfo, slot, estate); /* + * We lack the infrastructure to follow rules in README.tuplock + * section "Locking to write inplace-updated tables". Specifically, + * we lack infrastructure to lock tupleid before this file's + * ExecProcNode() call fetches the tuple's old columns. Just take a + * lock that silences check_lock_if_inplace_updateable_rel(). This + * doesn't actually protect inplace updates like those rules intend, + * so we may lose an inplace update that overlaps a superuser running + * "UPDATE pg_class" or "UPDATE pg_database". + */ +#ifdef USE_ASSERT_CHECKING + if (IsInplaceUpdateRelation(resultRelationDesc)) + { + lockedtid = *tupleid; + LockTuple(resultRelationDesc, &lockedtid, InplaceUpdateTupleLock); + } + else + ItemPointerSetInvalid(&lockedtid); +#endif + + /* * replace the heap tuple * * Note: if es_crosscheck_snapshot isn't InvalidSnapshot, we check @@ -1405,6 +1426,11 @@ lreplace: true /* wait for commit */ , &tmfd, &lockmode, &update_indexes); +#ifdef USE_ASSERT_CHECKING + if (ItemPointerIsValid(&lockedtid)) + UnlockTuple(resultRelationDesc, &lockedtid, InplaceUpdateTupleLock); +#endif + switch (result) { case TM_SelfModified: |