Hi, In [1] I added some verification to projection building, to check if the tupleslot passed to ExecBuildProjectionInfo() is compatible with the target list. One query in merge.sql [2] got flagged.
Trying to debug that issue, I found another problem. This leaves us with: 1) w/ inheritance INSERTed rows are not returned by RETURNING. This seems to just generally not work with MERGE 2) w/ inheritance the projection for insert that ExecInitMerge() builds sometimes uses mismatching columns between the slot passed to ExecBuildProjectionInfo() and tgtslot. The only reason this doesn't seem to immediately crash is 1). E.g. the attached repro-merge-inheritance.sql triggers [3] if the attached debugging patch is applied. I wouldn't be surprised if there were other issues around inheritance with mismatched column (order), but I didn't look further. Greetings, Andres Freund [1] https://postgr.es/m/smj2mopf4t654xinuyyq4azik2d5zp2g3lsv2o7vficegqq5c5%40v35iq4llqjpw [2] MERGE into measurement m USING new_measurement nm ON (m.city_id = nm.city_id and m.logdate=nm.logdate) WHEN MATCHED AND nm.peaktemp IS NULL THEN DELETE WHEN MATCHED THEN UPDATE SET peaktemp = greatest(m.peaktemp, nm.peaktemp), unitsales = m.unitsales + coalesce(nm.unitsales, 0) WHEN NOT MATCHED THEN INSERT (city_id, logdate, peaktemp, unitsales) VALUES (city_id, logdate, peaktemp, unitsales); triggers 2025-05-20 14:32:31.039 EDT [1617074][client backend][0/49:0][psql] WARNING: type mismatch: resno 1: slot (type: 0, name: ........pg.dropped.1........) vs expr (type: 23, name: city_id) 2025-05-20 14:32:31.039 EDT [1617074][client backend][0/49:0][psql] WARNING: TargetEntry: 2025-05-20 14:32:31.039 EDT [1617074][client backend][0/49:0][psql] DETAIL: {TARGETENTRY :expr {VAR :varno -1 :varattno 3 :vartype 23 :vartypmod -1 :varcollid 0 :varnullingrels (b) :varlevelsup 0 :varreturningtype 0 :varnosyn 2 :varattnosyn 1 :location 379 } :resno 1 :resname city_id :ressortgroupref 0 :resorigtbl 0 :resorigcol 0 :resjunk false } 2025-05-20 14:32:31.039 EDT [1617074][client backend][0/49:0][psql] WARNING: type mismatch: resno 2: slot (type: 23, name: peaktemp) vs expr (type: 1082, name: logdate) 2025-05-20 14:32:31.039 EDT [1617074][client backend][0/49:0][psql] WARNING: TargetEntry: 2025-05-20 14:32:31.039 EDT [1617074][client backend][0/49:0][psql] DETAIL: {TARGETENTRY :expr {VAR :varno -1 :varattno 4 :vartype 1082 :vartypmod -1 :varcollid 0 :varnullingrels (b) :varlevelsup 0 :varreturningtype 0 :varnosyn 2 :varattnosyn 2 :location 388 } :resno 2 :resname logdate :ressortgroupref 0 :resorigtbl 0 :resorigcol 0 :resjunk false } 2025-05-20 14:32:31.039 EDT [1617074][client backend][0/49:0][psql] WARNING: type mismatch: resno 3: slot (type: 1082, name: logdate) vs expr (type: 23, name: peaktemp) 2025-05-20 14:32:31.039 EDT [1617074][client backend][0/49:0][psql] WARNING: TargetEntry: 2025-05-20 14:32:31.039 EDT [1617074][client backend][0/49:0][psql] DETAIL: {TARGETENTRY :expr {VAR :varno -1 :varattno 1 :vartype 23 :vartypmod -1 :varcollid 0 :varnullingrels (b) :varlevelsup 0 :varreturningtype 0 :varnosyn 2 :varattnosyn 3 :location 397 } :resno 3 :resname peaktemp :ressortgroupref 0 :resorigtbl 0 :resorigcol 0 :resjunk false } 2025-05-20 14:32:31.039 EDT [1617074][client backend][0/49:0][psql] WARNING: type mismatch: resno 5: slot (type: 23, name: unitsales) vs expr (type: 25, name: last_action) 2025-05-20 14:32:31.039 EDT [1617074][client backend][0/49:0][psql] WARNING: TargetEntry: 2025-05-20 14:32:31.039 EDT [1617074][client backend][0/49:0][psql] DETAIL: {TARGETENTRY :expr {CONST :consttype 25 :consttypmod -1 :constcollid 100 :constlen -1 :constbyval false :constisnull false :location 418 :constvalue 16 [ 64 0 0 0 109 101 114 103 101 45 105 110 115 101 114 116 ] } :resno 5 :resname last_action :ressortgroupref 0 :resorigtbl 0 :resorigcol 0 :resjunk false } [3] 2025-05-21 11:24:55.111 EDT [1838296][client backend][0/16:0][psql] WARNING: type mismatch: resno 1: slot (type: 1700, name: dropme) vs expr (type: 25, name: key) 2025-05-21 11:24:55.112 EDT [1838296][client backend][0/16:0][psql] WARNING: TargetEntry: 2025-05-21 11:24:55.112 EDT [1838296][client backend][0/16:0][psql] DETAIL: {TARGETENTRY :expr {VAR :varno -1 :varattno 1 :vartype 25 :vartypmod -1 :varcollid 100 :varnullingrels (b) :varlevelsup 0 :varreturningtype 0 :varnosyn 2 :varattnosyn 1 :location 179 } :resno 1 :resname key :ressortgroupref 0 :resorigtbl 0 :resorigcol 0 :resjunk false }
diff --git i/src/backend/executor/execExpr.c w/src/backend/executor/execExpr.c
index f1569879b52..2972af3c189 100644
--- i/src/backend/executor/execExpr.c
+++ w/src/backend/executor/execExpr.c
@@ -346,6 +346,7 @@ ExecInitExprList(List *nodes, PlanState *parent)
return result;
}
+#include "nodes/print.h"
/*
* ExecBuildProjectionInfo
@@ -399,6 +400,24 @@ ExecBuildProjectionInfo(List *targetList,
AttrNumber attnum = 0;
bool isSafeVar = false;
+ if (slot && tle->expr != NULL)
+ {
+ Oid expr_type = exprType((Node *) tle->expr);
+ Form_pg_attribute slot_attr = TupleDescAttr(slot->tts_tupleDescriptor, tle->resno - 1);
+ Oid slot_type = slot_attr->atttypid;
+
+ if (expr_type != slot_type)
+ {
+ elog(WARNING, "type mismatch: resno %d: slot (type: %d, name: %s) vs expr (type: %d, name: %s)",
+ tle->resno, slot_type,
+ NameStr(slot_attr->attname),
+ expr_type,
+ tle->resname
+ );
+ elog_node_display(WARNING, "TargetEntry", tle, true);
+ }
+ }
+
/*
* If tlist expression is a safe non-system Var, use the fast-path
* ASSIGN_*_VAR opcodes. "Safe" means that we don't need to apply
repro-merge-inheritance.sql
Description: application/sql
