diff options
Diffstat (limited to 'src/backend/optimizer/util/clauses.c')
| -rw-r--r-- | src/backend/optimizer/util/clauses.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index a04ad6e99e6..ee6f4cdf4da 100644 --- a/src/backend/optimizer/util/clauses.c +++ b/src/backend/optimizer/util/clauses.c @@ -1190,13 +1190,27 @@ max_parallel_hazard_walker(Node *node, max_parallel_hazard_context *context) return true; } - if (IsA(node, NextValueExpr)) + else if (IsA(node, NextValueExpr)) { if (max_parallel_hazard_test(PROPARALLEL_UNSAFE, context)) return true; } /* + * Treat window functions as parallel-restricted because we aren't sure + * whether the input row ordering is fully deterministic, and the output + * of window functions might vary across workers if not. (In some cases, + * like where the window frame orders by a primary key, we could relax + * this restriction. But it doesn't currently seem worth expending extra + * effort to do so.) + */ + else if (IsA(node, WindowFunc)) + { + if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context)) + return true; + } + + /* * As a notational convenience for callers, look through RestrictInfo. */ else if (IsA(node, RestrictInfo)) |