diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c index 892b4e17e0..f0f3b4ffb0 100644 --- a/src/backend/executor/execExpr.c +++ b/src/backend/executor/execExpr.c @@ -1913,16 +1913,16 @@ ExecInitExprRec(Expr *node, ExprState *state, { /* generic record, use types of given expressions */ tupdesc = ExecTypeFromExprList(rowexpr->args); + /* ... but adopt RowExpr's column aliases */ + ExecTypeSetColNames(tupdesc, rowexpr->colnames); + /* Bless the tupdesc so it can be looked up later */ + BlessTupleDesc(tupdesc); } else { /* it's been cast to a named type, use that */ tupdesc = lookup_rowtype_tupdesc_copy(rowexpr->row_typeid, -1); } - /* In either case, adopt RowExpr's column aliases */ - ExecTypeSetColNames(tupdesc, rowexpr->colnames); - /* Bless the tupdesc in case it's now of type RECORD */ - BlessTupleDesc(tupdesc); /* * In the named-type case, the tupdesc could have more columns diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c index eb49817cee..b7b79e0b75 100644 --- a/src/backend/executor/execExprInterp.c +++ b/src/backend/executor/execExprInterp.c @@ -4021,12 +4021,8 @@ ExecEvalWholeRowVar(ExprState *state, ExprEvalStep *op, ExprContext *econtext) * generates an INT4 NULL regardless of the dropped column type). * If we find a dropped column and cannot verify that case (1) * holds, we have to use the slow path to check (2) for each row. - * - * If vartype is a domain over composite, just look through that - * to the base composite type. */ - var_tupdesc = lookup_rowtype_tupdesc_domain(variable->vartype, - -1, false); + var_tupdesc = lookup_rowtype_tupdesc(variable->vartype, -1); slot_tupdesc = slot->tts_tupleDescriptor; @@ -4063,9 +4059,8 @@ ExecEvalWholeRowVar(ExprState *state, ExprEvalStep *op, ExprContext *econtext) /* * Use the variable's declared rowtype as the descriptor for the - * output values, modulo possibly assigning new column names - * below. In particular, we *must* absorb any attisdropped - * markings. + * output values. In particular, we *must* absorb any + * attisdropped markings. */ oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory); output_tupdesc = CreateTupleDescCopy(var_tupdesc); @@ -4083,39 +4078,38 @@ ExecEvalWholeRowVar(ExprState *state, ExprEvalStep *op, ExprContext *econtext) oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory); output_tupdesc = CreateTupleDescCopy(slot->tts_tupleDescriptor); MemoryContextSwitchTo(oldcontext); - } - /* - * Construct a tuple descriptor for the composite values we'll - * produce, and make sure its record type is "blessed". The main - * reason to do this is to be sure that operations such as - * row_to_json() will see the desired column names when they look up - * the descriptor from the type information embedded in the composite - * values. - * - * We already got the correct physical datatype info above, but now we - * should try to find the source RTE and adopt its column aliases, in - * case they are different from the original rowtype's names. For - * example, in "SELECT foo(t) FROM tab t(x,y)", the first two columns - * in the composite output should be named "x" and "y" regardless of - * tab's column names. - * - * If we can't locate the RTE, assume the column names we've got are - * OK. (As of this writing, the only cases where we can't locate the - * RTE are in execution of trigger WHEN clauses, and then the Var will - * have the trigger's relation's rowtype, so its names are fine.) - * Also, if the creator of the RTE didn't bother to fill in an eref - * field, assume our column names are OK. (This happens in COPY, and - * perhaps other places.) - */ - if (econtext->ecxt_estate && - variable->varno <= econtext->ecxt_estate->es_range_table_size) - { - RangeTblEntry *rte = exec_rt_fetch(variable->varno, - econtext->ecxt_estate); + /* + * It's possible that the input slot is a relation scan slot and + * so is marked with that relation's rowtype. But we're supposed + * to be returning RECORD, so reset to that. + */ + output_tupdesc->tdtypeid = RECORDOID; + output_tupdesc->tdtypmod = -1; - if (rte->eref) - ExecTypeSetColNames(output_tupdesc, rte->eref->colnames); + /* + * We already got the correct physical datatype info above, but + * now we should try to find the source RTE and adopt its column + * aliases, since it's unlikely that the input slot has the + * desired names. + * + * If we can't locate the RTE, assume the column names we've got + * are OK. (As of this writing, the only cases where we can't + * locate the RTE are in execution of trigger WHEN clauses, and + * then the Var will have the trigger's relation's rowtype, so its + * names are fine.) Also, if the creator of the RTE didn't bother + * to fill in an eref field, assume our column names are OK. (This + * happens in COPY, and perhaps other places.) + */ + if (econtext->ecxt_estate && + variable->varno <= econtext->ecxt_estate->es_range_table_size) + { + RangeTblEntry *rte = exec_rt_fetch(variable->varno, + econtext->ecxt_estate); + + if (rte->eref) + ExecTypeSetColNames(output_tupdesc, rte->eref->colnames); + } } /* Bless the tupdesc if needed, and save it in the execution state */ diff --git a/src/backend/executor/execTuples.c b/src/backend/executor/execTuples.c index f447802843..5004b3b165 100644 --- a/src/backend/executor/execTuples.c +++ b/src/backend/executor/execTuples.c @@ -2022,51 +2022,40 @@ ExecTypeFromExprList(List *exprList) } /* - * ExecTypeSetColNames - set column names in a TupleDesc + * ExecTypeSetColNames - set column names in a RECORD TupleDesc * * Column names must be provided as an alias list (list of String nodes). - * - * For some callers, the supplied tupdesc has a named rowtype (not RECORD) - * and it is moderately likely that the alias list matches the column names - * already present in the tupdesc. If we do change any column names then - * we must reset the tupdesc's type to anonymous RECORD; but we avoid doing - * so if no names change. */ void ExecTypeSetColNames(TupleDesc typeInfo, List *namesList) { - bool modified = false; int colno = 0; ListCell *lc; + /* It's only OK to change col names in a not-yet-blessed RECORD type */ + Assert(typeInfo->tdtypeid == RECORDOID); + Assert(typeInfo->tdtypmod < 0); + foreach(lc, namesList) { char *cname = strVal(lfirst(lc)); Form_pg_attribute attr; - /* Guard against too-long names list */ + /* Guard against too-long names list (probably can't happen) */ if (colno >= typeInfo->natts) break; attr = TupleDescAttr(typeInfo, colno); colno++; - /* Ignore empty aliases (these must be for dropped columns) */ - if (cname[0] == '\0') + /* + * Do nothing for empty aliases or dropped columns (these cases + * probably can't arise in RECORD types, either) + */ + if (cname[0] == '\0' || attr->attisdropped) continue; - /* Change tupdesc only if alias is actually different */ - if (strcmp(cname, NameStr(attr->attname)) != 0) - { - namestrcpy(&(attr->attname), cname); - modified = true; - } - } - - /* If we modified the tupdesc, it's now a new record type */ - if (modified) - { - typeInfo->tdtypeid = RECORDOID; - typeInfo->tdtypmod = -1; + /* OK, assign the column name */ + namestrcpy(&(attr->attname), cname); } } diff --git a/src/test/regress/expected/rowtypes.out b/src/test/regress/expected/rowtypes.out index 0e71baf8fb..3245fb6a35 100644 --- a/src/test/regress/expected/rowtypes.out +++ b/src/test/regress/expected/rowtypes.out @@ -1010,14 +1010,15 @@ select row_to_json(i) from int8_tbl i; {"q1":4567890123456789,"q2":-4567890123456789} (5 rows) +-- since "i" is of type "int8_tbl", attaching aliases doesn't change anything: select row_to_json(i) from int8_tbl i(x,y); - row_to_json ----------------------------------------------- - {"x":123,"y":456} - {"x":123,"y":4567890123456789} - {"x":4567890123456789,"y":123} - {"x":4567890123456789,"y":4567890123456789} - {"x":4567890123456789,"y":-4567890123456789} + row_to_json +------------------------------------------------ + {"q1":123,"q2":456} + {"q1":123,"q2":4567890123456789} + {"q1":4567890123456789,"q2":123} + {"q1":4567890123456789,"q2":4567890123456789} + {"q1":4567890123456789,"q2":-4567890123456789} (5 rows) create temp view vv1 as select * from int8_tbl; @@ -1032,15 +1033,16 @@ select row_to_json(i) from vv1 i; (5 rows) select row_to_json(i) from vv1 i(x,y); - row_to_json ----------------------------------------------- - {"x":123,"y":456} - {"x":123,"y":4567890123456789} - {"x":4567890123456789,"y":123} - {"x":4567890123456789,"y":4567890123456789} - {"x":4567890123456789,"y":-4567890123456789} + row_to_json +------------------------------------------------ + {"q1":123,"q2":456} + {"q1":123,"q2":4567890123456789} + {"q1":4567890123456789,"q2":123} + {"q1":4567890123456789,"q2":4567890123456789} + {"q1":4567890123456789,"q2":-4567890123456789} (5 rows) +-- in these examples, we'll report the exposed column names of the subselect: select row_to_json(ss) from (select q1, q2 from int8_tbl) as ss; row_to_json diff --git a/src/test/regress/sql/rowtypes.sql b/src/test/regress/sql/rowtypes.sql index 845e3305f3..b8786603d9 100644 --- a/src/test/regress/sql/rowtypes.sql +++ b/src/test/regress/sql/rowtypes.sql @@ -417,12 +417,14 @@ select longname(f) from fullname f; -- select row_to_json(i) from int8_tbl i; +-- since "i" is of type "int8_tbl", attaching aliases doesn't change anything: select row_to_json(i) from int8_tbl i(x,y); create temp view vv1 as select * from int8_tbl; select row_to_json(i) from vv1 i; select row_to_json(i) from vv1 i(x,y); +-- in these examples, we'll report the exposed column names of the subselect: select row_to_json(ss) from (select q1, q2 from int8_tbl) as ss; select row_to_json(ss) from