Tender Wang <[email protected]> 于2026年6月29日周一 10:31写道： > > Hi Richard, > I applied the v2 patch; it fixed the reported issue in [1]. > But it failed on Chengpeng Yan's reported case. > > SELECT x, c > FROM ( > SELECT x, count(*) OVER (PARTITION BY x) AS c > FROM t > ) s > WHERE ascii(x) = 97; > NOTICE: using standard form "und-u-ks-level2" for ICU locale > "@colStrength=secondary" > CREATE COLLATION > CREATE TABLE > INSERT 0 2 > x | c > -----+--- > abc | 1 > (1 row) >
Only comparing expr's inputcollid to varcollid doesn't seem enough here. We don't know whether the FunExpr inside uses the inputcollid; in this case, ascii() is collation-unaware. Now we don't have the infrastructure to know whether a function is collation-aware. If we find a function wrapped on the Var, we give up the qual pushed down. We still have the optimization opportunity that if the OpExpr contains a bare Var on one side. -- Thanks, Tender Wang
