On 2017/02/16 2:08, Robert Haas wrote:
> On Wed, Feb 15, 2017 at 11:34 AM, Alvaro Herrera
> <alvhe...@2ndquadrant.com> wrote:
>> I think new-style partitioning is supposed to consider each partition as
>> an implementation detail of the table; the fact that you can manipulate
>> partitions separately does not really mean that they are their own
>> independent object. You don't stop to think "do I really want to drop
>> the TOAST table attached to this main table?" and attach a CASCADE
>> clause if so. You just drop the main table, and the toast one is
>> dropped automatically. I think new-style partitions should behave
>> equivalently.
>
> That's a reasonable point of view. I'd like to get some more opinions
> on this topic. I'm happy to have us do whatever most people want, but
> I'm worried that having table inheritance and table partitioning work
> differently will be create confusion. I'm also suspicious that there
> may be some implementation difficulties. On the hand, it does seem a
> little silly to say that DROP TABLE partitioned_table should always
> fail except in the degenerate case where there are no partitions, so
> maybe changing it is for the best.
So I count more than a few votes saying that we should be able to DROP
partitioned tables without specifying CASCADE.
I tried to implement that using the attached patch by having
StoreCatalogInheritance1() create DEPENDENCY_AUTO dependency between
parent and child if the child is a partition, instead of DEPENDENCY_NORMAL
that would otherwise be created. Now it seems that that is one way of
making sure that partitions are dropped when the root partitioned table is
dropped, not sure if the best; why create the pg_depend entries at all one
might ask. I chose it for now because that's the one with fewest lines of
change. Adjusted regression tests as well, since we recently tweaked
tests [1] to work around the irregularities of test output when using CASCADE.
Thanks,
Amit
[1] https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=c397814
>From 3b75f82b4f47e840074d0209323d8ab1f39ed676 Mon Sep 17 00:00:00 2001
From: amit <amitlangot...@gmail.com>
Date: Thu, 16 Feb 2017 15:56:44 +0900
Subject: [PATCH] Allow dropping partitioned table without CASCADE
Currently, a normal dependency is created between a inheritance
parent and child when creating the child. That means one must
specify CASCADE to drop the parent table if a child table exists.
When creating partitions as inheritance children, create auto
dependency instead, so that partitions are dropped automatically
when the parent is dropped i.e., without specifying CASCADE.
---
src/backend/commands/tablecmds.c | 26 ++++++++++++++++++--------
src/test/regress/expected/alter_table.out | 10 ++++------
src/test/regress/expected/create_table.out | 9 ++-------
src/test/regress/expected/inherit.out | 18 ------------------
src/test/regress/expected/insert.out | 7 ++-----
src/test/regress/expected/update.out | 5 -----
src/test/regress/sql/alter_table.sql | 10 ++++------
src/test/regress/sql/create_table.sql | 9 ++-------
src/test/regress/sql/insert.sql | 7 ++-----
9 files changed, 34 insertions(+), 67 deletions(-)
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index f33aa70da6..27b6556a71 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -289,9 +289,11 @@ static List *MergeAttributes(List *schema, List *supers, char relpersistence,
static bool MergeCheckConstraint(List *constraints, char *name, Node *expr);
static void MergeAttributesIntoExisting(Relation child_rel, Relation parent_rel);
static void MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel);
-static void StoreCatalogInheritance(Oid relationId, List *supers);
+static void StoreCatalogInheritance(Oid relationId, List *supers,
+ bool child_is_partition);
static void StoreCatalogInheritance1(Oid relationId, Oid parentOid,
- int16 seqNumber, Relation inhRelation);
+ int16 seqNumber, Relation inhRelation,
+ bool child_is_partition);
static int findAttrByName(const char *attributeName, List *schema);
static void AlterIndexNamespaces(Relation classRel, Relation rel,
Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved);
@@ -730,7 +732,7 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
typaddress);
/* Store inheritance information for new rel. */
- StoreCatalogInheritance(relationId, inheritOids);
+ StoreCatalogInheritance(relationId, inheritOids, stmt->partbound != NULL);
/*
* We must bump the command counter to make the newly-created relation
@@ -2245,7 +2247,8 @@ MergeCheckConstraint(List *constraints, char *name, Node *expr)
* supers is a list of the OIDs of the new relation's direct ancestors.
*/
static void
-StoreCatalogInheritance(Oid relationId, List *supers)
+StoreCatalogInheritance(Oid relationId, List *supers,
+ bool child_is_partition)
{
Relation relation;
int16 seqNumber;
@@ -2275,7 +2278,8 @@ StoreCatalogInheritance(Oid relationId, List *supers)
{
Oid parentOid = lfirst_oid(entry);
- StoreCatalogInheritance1(relationId, parentOid, seqNumber, relation);
+ StoreCatalogInheritance1(relationId, parentOid, seqNumber, relation,
+ child_is_partition);
seqNumber++;
}
@@ -2288,7 +2292,8 @@ StoreCatalogInheritance(Oid relationId, List *supers)
*/
static void
StoreCatalogInheritance1(Oid relationId, Oid parentOid,
- int16 seqNumber, Relation inhRelation)
+ int16 seqNumber, Relation inhRelation,
+ bool child_is_partition)
{
TupleDesc desc = RelationGetDescr(inhRelation);
Datum values[Natts_pg_inherits];
@@ -2322,7 +2327,10 @@ StoreCatalogInheritance1(Oid relationId, Oid parentOid,
childobject.objectId = relationId;
childobject.objectSubId = 0;
- recordDependencyOn(&childobject, &parentobject, DEPENDENCY_NORMAL);
+ if (!child_is_partition)
+ recordDependencyOn(&childobject, &parentobject, DEPENDENCY_NORMAL);
+ else
+ recordDependencyOn(&childobject, &parentobject, DEPENDENCY_AUTO);
/*
* Post creation hook of this inheritance. Since object_access_hook
@@ -10749,7 +10757,9 @@ CreateInheritance(Relation child_rel, Relation parent_rel)
StoreCatalogInheritance1(RelationGetRelid(child_rel),
RelationGetRelid(parent_rel),
inhseqno + 1,
- catalogRelation);
+ catalogRelation,
+ parent_rel->rd_rel->relkind ==
+ RELKIND_PARTITIONED_TABLE);
/* Now we're done with pg_inherits */
heap_close(catalogRelation, RowExclusiveLock);
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index b0e80a7788..0d1554a73e 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -3334,10 +3334,8 @@ ALTER TABLE list_parted2 DROP COLUMN b;
ERROR: cannot drop column named in partition key
ALTER TABLE list_parted2 ALTER COLUMN b TYPE text;
ERROR: cannot alter type of column named in partition key
--- cleanup: avoid using CASCADE
-DROP TABLE list_parted, part_1;
-DROP TABLE list_parted2, part_2, part_5, part_5_a;
-DROP TABLE range_parted, part1, part2;
+-- cleanup
+DROP TABLE list_parted, list_parted2, range_parted;
-- more tests for certain multi-level partitioning scenarios
create table p (a int, b int) partition by range (a, b);
create table p1 (b int, a int not null) partition by range (b);
@@ -3366,5 +3364,5 @@ insert into p1 (a, b) values (2, 3);
-- check that partition validation scan correctly detects violating rows
alter table p attach partition p1 for values from (1, 2) to (1, 10);
ERROR: partition constraint is violated by some row
--- cleanup: avoid using CASCADE
-drop table p, p1, p11;
+-- cleanup
+drop table p;
diff --git a/src/test/regress/expected/create_table.out b/src/test/regress/expected/create_table.out
index fc92cd92dd..bfad755e32 100644
--- a/src/test/regress/expected/create_table.out
+++ b/src/test/regress/expected/create_table.out
@@ -659,10 +659,5 @@ Check constraints:
"check_a" CHECK (length(a) > 0)
Number of partitions: 3 (Use \d+ to list them.)
--- cleanup: avoid using CASCADE
-DROP TABLE parted, part_a, part_b, part_c, part_c_1_10;
-DROP TABLE list_parted, part_1, part_2, part_null;
-DROP TABLE range_parted;
-DROP TABLE list_parted2, part_ab, part_null_z;
-DROP TABLE range_parted2, part0, part1, part2, part3;
-DROP TABLE range_parted3, part00, part10, part11, part12;
+-- cleanup
+DROP TABLE parted, list_parted, range_parted, list_parted2, range_parted2, range_parted3;
diff --git a/src/test/regress/expected/inherit.out b/src/test/regress/expected/inherit.out
index a8c8b28a75..623aa1db93 100644
--- a/src/test/regress/expected/inherit.out
+++ b/src/test/regress/expected/inherit.out
@@ -1844,22 +1844,4 @@ explain (costs off) select * from range_list_parted where a >= 30;
(11 rows)
drop table list_parted cascade;
-NOTICE: drop cascades to 3 other objects
-DETAIL: drop cascades to table part_ab_cd
-drop cascades to table part_ef_gh
-drop cascades to table part_null_xy
drop table range_list_parted cascade;
-NOTICE: drop cascades to 13 other objects
-DETAIL: drop cascades to table part_1_10
-drop cascades to table part_1_10_ab
-drop cascades to table part_1_10_cd
-drop cascades to table part_10_20
-drop cascades to table part_10_20_ab
-drop cascades to table part_10_20_cd
-drop cascades to table part_21_30
-drop cascades to table part_21_30_ab
-drop cascades to table part_21_30_cd
-drop cascades to table part_40_inf
-drop cascades to table part_40_inf_ab
-drop cascades to table part_40_inf_cd
-drop cascades to table part_40_inf_null
diff --git a/src/test/regress/expected/insert.out b/src/test/regress/expected/insert.out
index 81af3ef497..31cfa4e76e 100644
--- a/src/test/regress/expected/insert.out
+++ b/src/test/regress/expected/insert.out
@@ -314,10 +314,7 @@ select tableoid::regclass::text, a, min(b) as min_b, max(b) as max_b from list_p
(9 rows)
-- cleanup
-drop table part1, part2, part3, part4, range_parted;
-drop table part_ee_ff3_1, part_ee_ff3_2, part_ee_ff1, part_ee_ff2, part_ee_ff3;
-drop table part_ee_ff, part_gg2_2, part_gg2_1, part_gg2, part_gg1, part_gg;
-drop table part_aa_bb, part_cc_dd, part_null, list_parted;
+drop table range_parted, list_parted;
-- more tests for certain multi-level partitioning scenarios
create table p (a int, b int) partition by range (a, b);
create table p1 (b int not null, a int not null) partition by range ((b+0));
@@ -387,4 +384,4 @@ with ins (a, b, c) as
(5 rows)
-- cleanup
-drop table p, p1, p11, p12, p2, p3, p4;
+drop table p;
diff --git a/src/test/regress/expected/update.out b/src/test/regress/expected/update.out
index a1e9255450..af0d5bfffe 100644
--- a/src/test/regress/expected/update.out
+++ b/src/test/regress/expected/update.out
@@ -220,8 +220,3 @@ DETAIL: Failing row contains (b, 9).
update range_parted set b = b + 1 where b = 10;
-- cleanup
drop table range_parted cascade;
-NOTICE: drop cascades to 4 other objects
-DETAIL: drop cascades to table part_a_1_a_10
-drop cascades to table part_a_10_a_20
-drop cascades to table part_b_1_b_10
-drop cascades to table part_b_10_b_20
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index 7513769359..0787e785ce 100644
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -2194,10 +2194,8 @@ ALTER TABLE part_2 INHERIT inh_test;
ALTER TABLE list_parted2 DROP COLUMN b;
ALTER TABLE list_parted2 ALTER COLUMN b TYPE text;
--- cleanup: avoid using CASCADE
-DROP TABLE list_parted, part_1;
-DROP TABLE list_parted2, part_2, part_5, part_5_a;
-DROP TABLE range_parted, part1, part2;
+-- cleanup
+DROP TABLE list_parted, list_parted2, range_parted;
-- more tests for certain multi-level partitioning scenarios
create table p (a int, b int) partition by range (a, b);
@@ -2222,5 +2220,5 @@ insert into p1 (a, b) values (2, 3);
-- check that partition validation scan correctly detects violating rows
alter table p attach partition p1 for values from (1, 2) to (1, 10);
--- cleanup: avoid using CASCADE
-drop table p, p1, p11;
+-- cleanup
+drop table p;
diff --git a/src/test/regress/sql/create_table.sql b/src/test/regress/sql/create_table.sql
index 5f25c436ee..553c084a10 100644
--- a/src/test/regress/sql/create_table.sql
+++ b/src/test/regress/sql/create_table.sql
@@ -593,10 +593,5 @@ CREATE TABLE part_c_1_10 PARTITION OF part_c FOR VALUES FROM (1) TO (10);
-- returned.
\d parted
--- cleanup: avoid using CASCADE
-DROP TABLE parted, part_a, part_b, part_c, part_c_1_10;
-DROP TABLE list_parted, part_1, part_2, part_null;
-DROP TABLE range_parted;
-DROP TABLE list_parted2, part_ab, part_null_z;
-DROP TABLE range_parted2, part0, part1, part2, part3;
-DROP TABLE range_parted3, part00, part10, part11, part12;
+-- cleanup
+DROP TABLE parted, list_parted, range_parted, list_parted2, range_parted2, range_parted3;
diff --git a/src/test/regress/sql/insert.sql b/src/test/regress/sql/insert.sql
index 454e1ce2e7..dfdc24eba8 100644
--- a/src/test/regress/sql/insert.sql
+++ b/src/test/regress/sql/insert.sql
@@ -186,10 +186,7 @@ insert into list_parted (b) values (1);
select tableoid::regclass::text, a, min(b) as min_b, max(b) as max_b from list_parted group by 1, 2 order by 1;
-- cleanup
-drop table part1, part2, part3, part4, range_parted;
-drop table part_ee_ff3_1, part_ee_ff3_2, part_ee_ff1, part_ee_ff2, part_ee_ff3;
-drop table part_ee_ff, part_gg2_2, part_gg2_1, part_gg2, part_gg1, part_gg;
-drop table part_aa_bb, part_cc_dd, part_null, list_parted;
+drop table range_parted, list_parted;
-- more tests for certain multi-level partitioning scenarios
create table p (a int, b int) partition by range (a, b);
@@ -241,4 +238,4 @@ with ins (a, b, c) as
select a, b, min(c), max(c) from ins group by a, b order by 1;
-- cleanup
-drop table p, p1, p11, p12, p2, p3, p4;
+drop table p;
--
2.11.0
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