Tighten check for generated column in partition key expression

A generated column may end up being part of the partition key
expression, if it's specified as an expression e.g. "(<generated
column name>)" or if the partition key expression contains a whole-row
reference, even though we do not allow a generated column to be part
of partition key expression.  Fix this hole.

Co-authored-by: jian he <jian.universality@gmail.com>
Co-authored-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com>
Discussion: https://www.postgresql.org/message-id/flat/CACJufxF%3DWDGthXSAQr9thYUsfx_1_t9E6N8tE3B8EqXcVoVfQw%40mail.gmail.com

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index b6f780c03b2396453302b97694eb9e126536fe8b..a5d1b458c6942c358aeffe2f9242d8e95227bc70 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -17636,6 +17636,8 @@ ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNu
                        /* Expression */
                        Node       *expr = pelem->expr;
                        char            partattname[16];
+                       Bitmapset  *expr_attrs = NULL;
+                       int                     i;
 
                        Assert(expr != NULL);
                        atttype = exprType(expr);
@@ -17659,9 +17661,55 @@ ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNu
                        while (IsA(expr, CollateExpr))
                                expr = (Node *) ((CollateExpr *) expr)->arg;
 
+                       /*
+                        * Examine all the columns in the partition key expression. When
+                        * the whole-row reference is present, examine all the columns of
+                        * the partitioned table.
+                        */
+                       pull_varattnos(expr, 1, &expr_attrs);
+                       if (bms_is_member(0 - FirstLowInvalidHeapAttributeNumber, expr_attrs))
+                       {
+                               expr_attrs = bms_add_range(expr_attrs,
+                                                                                  1 - FirstLowInvalidHeapAttributeNumber,
+                                                                                  RelationGetNumberOfAttributes(rel) - FirstLowInvalidHeapAttributeNumber);
+                               expr_attrs = bms_del_member(expr_attrs, 0 - FirstLowInvalidHeapAttributeNumber);
+                       }
+
+                       i = -1;
+                       while ((i = bms_next_member(expr_attrs, i)) >= 0)
+                       {
+                               AttrNumber      attno = i + FirstLowInvalidHeapAttributeNumber;
+
+                               Assert(attno != 0);
+
+                               /*
+                                * Cannot allow system column references, since that would
+                                * make partition routing impossible: their values won't be
+                                * known yet when we need to do that.
+                                */
+                               if (attno < 0)
+                                       ereport(ERROR,
+                                                       (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+                                                        errmsg("partition key expressions cannot contain system column references")));
+
+                               /*
+                                * Generated columns cannot work: They are computed after
+                                * BEFORE triggers, but partition routing is done before all
+                                * triggers.
+                                */
+                               if (TupleDescAttr(RelationGetDescr(rel), attno - 1)->attgenerated)
+                                       ereport(ERROR,
+                                                       (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+                                                        errmsg("cannot use generated column in partition key"),
+                                                        errdetail("Column \"%s\" is a generated column.",
+                                                                          get_attname(RelationGetRelid(rel), attno, false)),
+                                                        parser_errposition(pstate, pelem->location)));
+                       }
+
                        if (IsA(expr, Var) &&
                                ((Var *) expr)->varattno > 0)
                        {
+
                                /*
                                 * User wrote "(column)" or "(column COLLATE something)".
                                 * Treat it like simple attribute anyway.
@@ -17670,9 +17718,6 @@ ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNu
                        }
                        else
                        {
-                               Bitmapset  *expr_attrs = NULL;
-                               int                     i;
-
                                partattrs[attn] = 0;    /* marks the column as expression */
                                *partexprs = lappend(*partexprs, expr);
 
@@ -17682,41 +17727,6 @@ ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNu
                                 * on the EXPR_KIND_ for partition expressions.
                                 */
 
-                               /*
-                                * Cannot allow system column references, since that would
-                                * make partition routing impossible: their values won't be
-                                * known yet when we need to do that.
-                                */
-                               pull_varattnos(expr, 1, &expr_attrs);
-                               for (i = FirstLowInvalidHeapAttributeNumber; i < 0; i++)
-                               {
-                                       if (bms_is_member(i - FirstLowInvalidHeapAttributeNumber,
-                                                                         expr_attrs))
-                                               ereport(ERROR,
-                                                               (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
-                                                                errmsg("partition key expressions cannot contain system column references")));
-                               }
-
-                               /*
-                                * Generated columns cannot work: They are computed after
-                                * BEFORE triggers, but partition routing is done before all
-                                * triggers.
-                                */
-                               i = -1;
-                               while ((i = bms_next_member(expr_attrs, i)) >= 0)
-                               {
-                                       AttrNumber      attno = i + FirstLowInvalidHeapAttributeNumber;
-
-                                       if (attno > 0 &&
-                                               TupleDescAttr(RelationGetDescr(rel), attno - 1)->attgenerated)
-                                               ereport(ERROR,
-                                                               (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
-                                                                errmsg("cannot use generated column in partition key"),
-                                                                errdetail("Column \"%s\" is a generated column.",
-                                                                                  get_attname(RelationGetRelid(rel), attno, false)),
-                                                                parser_errposition(pstate, pelem->location)));
-                               }
-
                                /*
                                 * Preprocess the expression before checking for mutability.
                                 * This is essential for the reasons described in

diff --git a/src/test/regress/expected/generated.out b/src/test/regress/expected/generated.out
index 50709dbe8020fe5545b7a0b7824924c64df2e4d2..4905f700c62ee9fe2753ab4d08ccc522086cb72d 100644 (file)
--- a/src/test/regress/expected/generated.out
+++ b/src/test/regress/expected/generated.out
@@ -820,11 +820,26 @@ ERROR:  cannot use generated column in partition key
 LINE 1: ...ENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f3);
                                                                    ^
 DETAIL:  Column "f3" is a generated column.
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3));
+ERROR:  cannot use generated column in partition key
+LINE 1: ...ERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3));
+                                                                 ^
+DETAIL:  Column "f3" is a generated column.
 CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3 * 3));
 ERROR:  cannot use generated column in partition key
 LINE 1: ...ED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3 * 3));
                                                              ^
 DETAIL:  Column "f3" is a generated column.
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((gtest_part_key));
+ERROR:  cannot use generated column in partition key
+LINE 1: ...ED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((gtest_par...
+                                                             ^
+DETAIL:  Column "f3" is a generated column.
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((gtest_part_key is not null));
+ERROR:  cannot use generated column in partition key
+LINE 1: ...ED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((gtest_par...
+                                                             ^
+DETAIL:  Column "f3" is a generated column.
 -- ALTER TABLE ... ADD COLUMN
 CREATE TABLE gtest25 (a int PRIMARY KEY);
 INSERT INTO gtest25 VALUES (3), (4);

diff --git a/src/test/regress/sql/generated.sql b/src/test/regress/sql/generated.sql
index ec74be7886b24aaeec0fc57bc05f13a8106fd52d..ca97461c772d72bca8a4297eac6995496a0572cc 100644 (file)
--- a/src/test/regress/sql/generated.sql
+++ b/src/test/regress/sql/generated.sql
@@ -428,7 +428,10 @@ SELECT * FROM gtest_child3;
 
 -- generated columns in partition key (not allowed)
 CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f3);
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3));
 CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3 * 3));
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((gtest_part_key));
+CREATE TABLE gtest_part_key (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((gtest_part_key is not null));
 
 -- ALTER TABLE ... ADD COLUMN
 CREATE TABLE gtest25 (a int PRIMARY KEY);