Fix partitioned index creation with foreign partitions

When a partitioned tables contains foreign tables as partitions, it is
not possible to implement unique or primary key indexes -- but when
regular indexes are created, there is no reason to do anything other
than ignoring such partitions.  We were raising errors upon encountering
the foreign partitions, which is unfriendly and doesn't protect against
any actual problems.

Relax this restriction so that index creation is allowed on partitioned
tables containing foreign partitions, becoming a no-op on them.  (We may
later want to redefine this so that the FDW is told to create the
indexes on the foreign side.)  This applies to CREATE INDEX, as well as
ALTER TABLE / ATTACH PARTITION and CREATE TABLE / PARTITION OF.

Backpatch to 11, where indexes on partitioned tables were introduced.

Discussion: https://postgr.es/m/15724-d5a58fa9472eef4f@postgresql.org
Author: Álvaro Herrera
Reviewed-by: Amit Langote

diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml
index f5ad7659f72d3cf015db218e9fb6449216f96075..90bf19564c6801113fa360c95713f339152c2772 100644 (file)
--- a/doc/src/sgml/ref/alter_table.sgml
+++ b/doc/src/sgml/ref/alter_table.sgml
@@ -845,7 +845,7 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
       as if <command>ALTER INDEX ATTACH PARTITION</command> had been executed.
       Note that if the existing table is a foreign table, it is currently not
       allowed to attach the table as a partition of the target table if there
-      are indexes on the target table.  (See also
+      are <literal>UNIQUE</literal> indexes on the target table.  (See also
       <xref linkend="sql-createforeigntable"/>.)
      </para>
 

diff --git a/doc/src/sgml/ref/create_foreign_table.sgml b/doc/src/sgml/ref/create_foreign_table.sgml
index 25d2f09ed20efce88b19872ab8ce53ccf9a653b7..9d266f272a7ef27bb335198ca52c860ec491cc5e 100644 (file)
--- a/doc/src/sgml/ref/create_foreign_table.sgml
+++ b/doc/src/sgml/ref/create_foreign_table.sgml
@@ -170,8 +170,8 @@ CHECK ( <replaceable class="parameter">expression</replaceable> ) [ NO INHERIT ]
       See the similar form of
       <xref linkend="sql-createtable"/> for more details.
       Note that it is currently not allowed to create the foreign table as a
-      partition of the parent table if there are indexes on the parent table.
-      (See also
+      partition of the parent table if there are <literal>UNIQUE</literal>
+      indexes on the parent table.  (See also
       <link linkend="sql-altertable"><command>ALTER TABLE ATTACH PARTITION</command></link>.)
      </para>
     </listitem>

diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index a3cbeff95008beddf88b7390ad4932fe37c116eb..cdbb56f1a4abf39436c942b7119e1da2cc2ff04a 100644 (file)
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -1085,6 +1085,26 @@ DefineIndex(Oid relationId,
                                int                     maplen;
 
                                childrel = table_open(childRelid, lockmode);
+
+                               /*
+                                * Don't try to create indexes on foreign tables, though.
+                                * Skip those if a regular index, or fail if trying to create
+                                * a constraint index.
+                                */
+                               if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+                               {
+                                       if (stmt->unique || stmt->primary)
+                                               ereport(ERROR,
+                                                               (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+                                                                errmsg("cannot create unique index on partitioned table \"%s\"",
+                                                                               RelationGetRelationName(rel)),
+                                                                errdetail("Table \"%s\" contains partitions that are foreign tables.",
+                                                                               RelationGetRelationName(rel))));
+
+                                       table_close(childrel, lockmode);
+                                       continue;
+                               }
+
                                childidxs = RelationGetIndexList(childrel);
                                attmap =
                                        convert_tuples_by_name_map(RelationGetDescr(childrel),

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index ba59fc708a9952acd211812083b738c220b5cbf9..7dcd634a1aea9c99d494a75489504faa610f36a2 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -1069,6 +1069,22 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
                        IndexStmt  *idxstmt;
                        Oid                     constraintOid;
 
+                       if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+                       {
+                               if (idxRel->rd_index->indisunique)
+                                       ereport(ERROR,
+                                                       (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+                                                        errmsg("cannot create foreign partition of partitioned table \"%s\"",
+                                                                       RelationGetRelationName(parent)),
+                                                        errdetail("Table \"%s\" contains indexes that are unique.",
+                                                                       RelationGetRelationName(parent))));
+                               else
+                               {
+                                       index_close(idxRel, AccessShareLock);
+                                       continue;
+                               }
+                       }
+
                        attmap = convert_tuples_by_name_map(RelationGetDescr(rel),
                                                                                                RelationGetDescr(parent),
                                                                                                gettext_noop("could not convert row type"));
@@ -15722,6 +15738,34 @@ AttachPartitionEnsureIndexes(Relation rel, Relation attachrel)
                i++;
        }
 
+       /*
+        * If we're attaching a foreign table, we must fail if any of the indexes
+        * is a constraint index; otherwise, there's nothing to do here.  Do this
+        * before starting work, to avoid wasting the effort of building a few
+        * non-unique indexes before coming across a unique one.
+        */
+       if (attachrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
+       {
+               foreach(cell, idxes)
+               {
+                       Oid                     idx = lfirst_oid(cell);
+                       Relation        idxRel = index_open(idx, AccessShareLock);
+
+                       if (idxRel->rd_index->indisunique ||
+                               idxRel->rd_index->indisprimary)
+                               ereport(ERROR,
+                                               (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+                                                errmsg("cannot attach foreign table \"%s\" as partition of partitioned table \"%s\"",
+                                                               RelationGetRelationName(attachrel),
+                                                               RelationGetRelationName(rel)),
+                                                errdetail("Table \"%s\" contains unique indexes.",
+                                                                  RelationGetRelationName(rel))));
+                       index_close(idxRel, AccessShareLock);
+               }
+
+               goto out;
+       }
+
        /*
         * For each index on the partitioned table, find a matching one in the
         * partition-to-be; if one is not found, create one.
@@ -15824,6 +15868,7 @@ AttachPartitionEnsureIndexes(Relation rel, Relation attachrel)
                index_close(idxRel, AccessShareLock);
        }
 
+out:
        /* Clean up. */
        for (i = 0; i < list_length(attachRelIdxs); i++)
                index_close(attachrelIdxRels[i], AccessShareLock);

diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 9578b5c7619b35c7d5fef5d049b40b2cc66ece0c..05ec7f3ac61764e7da8b903390894310dc80afba 100644 (file)
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -1347,10 +1347,16 @@ ProcessUtilitySlow(ParseState *pstate,
 
                                                        if (relkind != RELKIND_RELATION &&
                                                                relkind != RELKIND_MATVIEW &&
-                                                               relkind != RELKIND_PARTITIONED_TABLE)
+                                                               relkind != RELKIND_PARTITIONED_TABLE &&
+                                                               relkind != RELKIND_FOREIGN_TABLE)
+                                                               elog(ERROR, "unexpected relkind \"%c\" on partition \"%s\"",
+                                                                        relkind, stmt->relation->relname);
+
+                                                       if (relkind == RELKIND_FOREIGN_TABLE &&
+                                                               (stmt->unique || stmt->primary))
                                                                ereport(ERROR,
-                                                                               (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
-                                                                                errmsg("cannot create index on partitioned table \"%s\"",
+                                                                               (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+                                                                                errmsg("cannot create unique index on partitioned table \"%s\"",
                                                                                                stmt->relation->relname),
                                                                                 errdetail("Table \"%s\" contains partitions that are foreign tables.",
                                                                                                   stmt->relation->relname)));

diff --git a/src/test/regress/expected/foreign_data.out b/src/test/regress/expected/foreign_data.out
index c81e4bda80757d7004c6e65b5e382a9b7835d45f..b9e25820bc02f27566b59dece4f11a25e3e6904f 100644 (file)
--- a/src/test/regress/expected/foreign_data.out
+++ b/src/test/regress/expected/foreign_data.out
@@ -748,10 +748,62 @@ ERROR:  foreign-data wrapper "dummy" has no handler
 CREATE TABLE lt1 (a INT) PARTITION BY RANGE (a);
 CREATE FOREIGN TABLE ft_part1
   PARTITION OF lt1 FOR VALUES FROM (0) TO (1000) SERVER s0;
-CREATE INDEX ON lt1 (a);                                        -- ERROR
-ERROR:  cannot create index on partitioned table "lt1"
+CREATE INDEX ON lt1 (a);                              -- skips partition
+CREATE UNIQUE INDEX ON lt1 (a);                                 -- ERROR
+ERROR:  cannot create unique index on partitioned table "lt1"
 DETAIL:  Table "lt1" contains partitions that are foreign tables.
+ALTER TABLE lt1 ADD PRIMARY KEY (a);                            -- ERROR
+ERROR:  cannot create unique index on partitioned table "lt1"
+DETAIL:  Table "lt1" contains partitions that are foreign tables.
+DROP TABLE lt1;
+CREATE TABLE lt1 (a INT) PARTITION BY RANGE (a);
+CREATE INDEX ON lt1 (a);
+CREATE FOREIGN TABLE ft_part1
+  PARTITION OF lt1 FOR VALUES FROM (0) TO (1000) SERVER s0;
+CREATE FOREIGN TABLE ft_part2 (a INT) SERVER s0;
+ALTER TABLE lt1 ATTACH PARTITION ft_part2 FOR VALUES FROM (1000) TO (2000);
+DROP FOREIGN TABLE ft_part1, ft_part2;
+CREATE UNIQUE INDEX ON lt1 (a);
+ALTER TABLE lt1 ADD PRIMARY KEY (a);
+CREATE FOREIGN TABLE ft_part1
+  PARTITION OF lt1 FOR VALUES FROM (0) TO (1000) SERVER s0;     -- ERROR
+ERROR:  cannot create foreign partition of partitioned table "lt1"
+DETAIL:  Table "lt1" contains indexes that are unique.
+CREATE FOREIGN TABLE ft_part2 (a INT NOT NULL) SERVER s0;
+ALTER TABLE lt1 ATTACH PARTITION ft_part2
+  FOR VALUES FROM (1000) TO (2000);                             -- ERROR
+ERROR:  cannot attach foreign table "ft_part2" as partition of partitioned table "lt1"
+DETAIL:  Table "lt1" contains unique indexes.
+DROP TABLE lt1;
+DROP FOREIGN TABLE ft_part2;
+CREATE TABLE lt1 (a INT) PARTITION BY RANGE (a);
+CREATE INDEX ON lt1 (a);
+CREATE TABLE lt1_part1
+  PARTITION OF lt1 FOR VALUES FROM (0) TO (1000)
+  PARTITION BY RANGE (a);
+CREATE FOREIGN TABLE ft_part_1_1
+  PARTITION OF lt1_part1 FOR VALUES FROM (0) TO (100) SERVER s0;
+CREATE FOREIGN TABLE ft_part_1_2 (a INT) SERVER s0;
+ALTER TABLE lt1_part1 ATTACH PARTITION ft_part_1_2 FOR VALUES FROM (100) TO (200);
+CREATE UNIQUE INDEX ON lt1 (a);
+ERROR:  cannot create unique index on partitioned table "lt1"
+DETAIL:  Table "lt1" contains partitions that are foreign tables.
+ALTER TABLE lt1 ADD PRIMARY KEY (a);
+ERROR:  cannot create unique index on partitioned table "lt1_part1"
+DETAIL:  Table "lt1_part1" contains partitions that are foreign tables.
+DROP FOREIGN TABLE ft_part_1_1, ft_part_1_2;
+CREATE UNIQUE INDEX ON lt1 (a);
+ALTER TABLE lt1 ADD PRIMARY KEY (a);
+CREATE FOREIGN TABLE ft_part_1_1
+  PARTITION OF lt1_part1 FOR VALUES FROM (0) TO (100) SERVER s0;
+ERROR:  cannot create foreign partition of partitioned table "lt1_part1"
+DETAIL:  Table "lt1_part1" contains indexes that are unique.
+CREATE FOREIGN TABLE ft_part_1_2 (a INT NOT NULL) SERVER s0;
+ALTER TABLE lt1_part1 ATTACH PARTITION ft_part_1_2 FOR VALUES FROM (100) TO (200);
+ERROR:  cannot attach foreign table "ft_part_1_2" as partition of partitioned table "lt1_part1"
+DETAIL:  Table "lt1_part1" contains unique indexes.
 DROP TABLE lt1;
+DROP FOREIGN TABLE ft_part_1_2;
 -- ALTER FOREIGN TABLE
 COMMENT ON FOREIGN TABLE ft1 IS 'foreign table';
 COMMENT ON FOREIGN TABLE ft1 IS NULL;

diff --git a/src/test/regress/sql/foreign_data.sql b/src/test/regress/sql/foreign_data.sql
index c646ed91526865720fc462ea14ae85111f0c27bc..73f9f621d8ff9d06dad556142ba86b2591848c5f 100644 (file)
--- a/src/test/regress/sql/foreign_data.sql
+++ b/src/test/regress/sql/foreign_data.sql
@@ -318,9 +318,49 @@ EXPLAIN SELECT * FROM ft1;                                      -- ERROR
 CREATE TABLE lt1 (a INT) PARTITION BY RANGE (a);
 CREATE FOREIGN TABLE ft_part1
   PARTITION OF lt1 FOR VALUES FROM (0) TO (1000) SERVER s0;
-CREATE INDEX ON lt1 (a);                                        -- ERROR
+CREATE INDEX ON lt1 (a);                              -- skips partition
+CREATE UNIQUE INDEX ON lt1 (a);                                 -- ERROR
+ALTER TABLE lt1 ADD PRIMARY KEY (a);                            -- ERROR
 DROP TABLE lt1;
 
+CREATE TABLE lt1 (a INT) PARTITION BY RANGE (a);
+CREATE INDEX ON lt1 (a);
+CREATE FOREIGN TABLE ft_part1
+  PARTITION OF lt1 FOR VALUES FROM (0) TO (1000) SERVER s0;
+CREATE FOREIGN TABLE ft_part2 (a INT) SERVER s0;
+ALTER TABLE lt1 ATTACH PARTITION ft_part2 FOR VALUES FROM (1000) TO (2000);
+DROP FOREIGN TABLE ft_part1, ft_part2;
+CREATE UNIQUE INDEX ON lt1 (a);
+ALTER TABLE lt1 ADD PRIMARY KEY (a);
+CREATE FOREIGN TABLE ft_part1
+  PARTITION OF lt1 FOR VALUES FROM (0) TO (1000) SERVER s0;     -- ERROR
+CREATE FOREIGN TABLE ft_part2 (a INT NOT NULL) SERVER s0;
+ALTER TABLE lt1 ATTACH PARTITION ft_part2
+  FOR VALUES FROM (1000) TO (2000);                             -- ERROR
+DROP TABLE lt1;
+DROP FOREIGN TABLE ft_part2;
+
+CREATE TABLE lt1 (a INT) PARTITION BY RANGE (a);
+CREATE INDEX ON lt1 (a);
+CREATE TABLE lt1_part1
+  PARTITION OF lt1 FOR VALUES FROM (0) TO (1000)
+  PARTITION BY RANGE (a);
+CREATE FOREIGN TABLE ft_part_1_1
+  PARTITION OF lt1_part1 FOR VALUES FROM (0) TO (100) SERVER s0;
+CREATE FOREIGN TABLE ft_part_1_2 (a INT) SERVER s0;
+ALTER TABLE lt1_part1 ATTACH PARTITION ft_part_1_2 FOR VALUES FROM (100) TO (200);
+CREATE UNIQUE INDEX ON lt1 (a);
+ALTER TABLE lt1 ADD PRIMARY KEY (a);
+DROP FOREIGN TABLE ft_part_1_1, ft_part_1_2;
+CREATE UNIQUE INDEX ON lt1 (a);
+ALTER TABLE lt1 ADD PRIMARY KEY (a);
+CREATE FOREIGN TABLE ft_part_1_1
+  PARTITION OF lt1_part1 FOR VALUES FROM (0) TO (100) SERVER s0;
+CREATE FOREIGN TABLE ft_part_1_2 (a INT NOT NULL) SERVER s0;
+ALTER TABLE lt1_part1 ATTACH PARTITION ft_part_1_2 FOR VALUES FROM (100) TO (200);
+DROP TABLE lt1;
+DROP FOREIGN TABLE ft_part_1_2;
+
 -- ALTER FOREIGN TABLE
 COMMENT ON FOREIGN TABLE ft1 IS 'foreign table';
 COMMENT ON FOREIGN TABLE ft1 IS NULL;