diff options
Diffstat (limited to 'src/backend/optimizer/util/clauses.c')
| -rw-r--r-- | src/backend/optimizer/util/clauses.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index 6ac25dc6638..b692e18e3d4 100644 --- a/src/backend/optimizer/util/clauses.c +++ b/src/backend/optimizer/util/clauses.c @@ -672,9 +672,13 @@ find_window_functions_walker(Node *node, WindowFuncLists *lists) if (wfunc->winref > lists->maxWinRef) elog(ERROR, "WindowFunc contains out-of-range winref %u", wfunc->winref); - lists->windowFuncs[wfunc->winref] = - lappend(lists->windowFuncs[wfunc->winref], wfunc); - lists->numWindowFuncs++; + /* eliminate duplicates, so that we avoid repeated computation */ + if (!list_member(lists->windowFuncs[wfunc->winref], wfunc)) + { + lists->windowFuncs[wfunc->winref] = + lappend(lists->windowFuncs[wfunc->winref], wfunc); + lists->numWindowFuncs++; + } /* * We assume that the parser checked that there are no window |