Thanks for commenting.
On 2018/10/19 15:17, Michael Paquier wrote:
> On Fri, Oct 19, 2018 at 01:45:03AM -0400, Tom Lane wrote:
>> Amit Langote <[email protected]> writes:
>>> Should relhassubclass be set/reset for partitioned indexes?
>>
>> Seems like a reasonable idea to me, at least the "set" end of it.
>> We don't ever clear relhassubclass for tables, so maybe that's
>> not necessary for indexes either.
We *do* reset opportunistically during analyze of inheritance parent; the
following code in acquire_inherited_sample_rows() can reset it:
/*
* Check that there's at least one descendant, else fail. This could
* happen despite analyze_rel's relhassubclass check, if table once had a
* child but no longer does. In that case, we can clear the
* relhassubclass field so as not to make the same mistake again later.
* (This is safe because we hold ShareUpdateExclusiveLock.)
*/
if (list_length(tableOIDs) < 2)
{
/* CCI because we already updated the pg_class row in this command */
CommandCounterIncrement();
SetRelationHasSubclass(RelationGetRelid(onerel), false);
ereport(elevel,
(errmsg("skipping analyze of \"%s.%s\" inheritance tree ---
this inheritance tree contains no child tables",
get_namespace_name(RelationGetNamespace(onerel)),
RelationGetRelationName(onerel))));
return 0;
}
Similarly, perhaps we can make REINDEX on a partitioned index reset the
flag if it doesn't find any children. We won't be able to do that today
though, because:
static void
ReindexPartitionedIndex(Relation parentIdx)
{
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("REINDEX is not yet implemented for partitioned
indexes")));
}
> No objections to the proposal. Allowing find_inheritance_children to
> find index trees for partitioned indexes could be actually useful for
> extensions like pg_partman.
Thanks. Attached a patch to set relhassubclass when an index partition is
added to a partitioned index.
Regards,
Amit
>From f0c01ab41b35a5f21a90b0294d8216da78eb8882 Mon Sep 17 00:00:00 2001
From: amit <[email protected]>
Date: Fri, 19 Oct 2018 17:05:00 +0900
Subject: [PATCH 1/2] Set relhassubclass on index parents
---
src/backend/catalog/index.c | 5 ++++
src/backend/commands/indexcmds.c | 4 +++
src/test/regress/expected/indexing.out | 46 +++++++++++++++++++++-------------
src/test/regress/sql/indexing.sql | 11 ++++++--
4 files changed, 46 insertions(+), 20 deletions(-)
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index f1ef4c319a..62cc6a5bb9 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -996,8 +996,13 @@ index_create(Relation heapRelation,
/* update pg_inherits, if needed */
if (OidIsValid(parentIndexRelid))
+ {
StoreSingleInheritance(indexRelationId, parentIndexRelid, 1);
+ /* Also, set the parent's relhassubclass. */
+ SetRelationHasSubclass(parentIndexRelid, true);
+ }
+
/*
* Register constraint and dependencies for the index.
*
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 3975f62c00..c392352871 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -2608,6 +2608,10 @@ IndexSetParentIndex(Relation partitionIdx, Oid parentOid)
systable_endscan(scan);
relation_close(pg_inherits, RowExclusiveLock);
+ /* If we added an index partition to parent, set its relhassubclass. */
+ if (OidIsValid(parentOid))
+ SetRelationHasSubclass(parentOid, true);
+
if (fix_dependencies)
{
ObjectAddress partIdx;
diff --git a/src/test/regress/expected/indexing.out
b/src/test/regress/expected/indexing.out
index 225f4e9527..710b32192f 100644
--- a/src/test/regress/expected/indexing.out
+++ b/src/test/regress/expected/indexing.out
@@ -1,25 +1,35 @@
-- Creating an index on a partitioned table makes the partitions
-- automatically get the index
create table idxpart (a int, b int, c text) partition by range (a);
+-- relhassubclass of a partitioned index is false before creating its partition
+-- it will be set below once partitions get created
+create index check_relhassubclass_of_this on idxpart (a);
+select relhassubclass from pg_class where relname =
'check_relhassubclass_of_this';
+ relhassubclass
+----------------
+ f
+(1 row)
+
+drop index check_relhassubclass_of_this;
create table idxpart1 partition of idxpart for values from (0) to (10);
create table idxpart2 partition of idxpart for values from (10) to (100)
partition by range (b);
create table idxpart21 partition of idxpart2 for values from (0) to (100);
create index on idxpart (a);
-select relname, relkind, inhparent::regclass
+select relname, relkind, relhassubclass, inhparent::regclass
from pg_class left join pg_index ix on (indexrelid = oid)
left join pg_inherits on (ix.indexrelid = inhrelid)
where relname like 'idxpart%' order by relname;
- relname | relkind | inhparent
------------------+---------+----------------
- idxpart | p |
- idxpart1 | r |
- idxpart1_a_idx | i | idxpart_a_idx
- idxpart2 | p |
- idxpart21 | r |
- idxpart21_a_idx | i | idxpart2_a_idx
- idxpart2_a_idx | I | idxpart_a_idx
- idxpart_a_idx | I |
+ relname | relkind | relhassubclass | inhparent
+-----------------+---------+----------------+----------------
+ idxpart | p | t |
+ idxpart1 | r | f |
+ idxpart1_a_idx | i | f | idxpart_a_idx
+ idxpart2 | p | t |
+ idxpart21 | r | f |
+ idxpart21_a_idx | i | f | idxpart2_a_idx
+ idxpart2_a_idx | I | t | idxpart_a_idx
+ idxpart_a_idx | I | t |
(8 rows)
drop table idxpart;
@@ -110,16 +120,16 @@ Partition of: idxpart FOR VALUES FROM (0, 0) TO (10, 10)
Indexes:
"idxpart1_a_b_idx" btree (a, b)
-select relname, relkind, inhparent::regclass
+select relname, relkind, relhassubclass, inhparent::regclass
from pg_class left join pg_index ix on (indexrelid = oid)
left join pg_inherits on (ix.indexrelid = inhrelid)
where relname like 'idxpart%' order by relname;
- relname | relkind | inhparent
-------------------+---------+-----------------
- idxpart | p |
- idxpart1 | r |
- idxpart1_a_b_idx | i | idxpart_a_b_idx
- idxpart_a_b_idx | I |
+ relname | relkind | relhassubclass | inhparent
+------------------+---------+----------------+-----------------
+ idxpart | p | t |
+ idxpart1 | r | f |
+ idxpart1_a_b_idx | i | f | idxpart_a_b_idx
+ idxpart_a_b_idx | I | t |
(4 rows)
drop table idxpart;
diff --git a/src/test/regress/sql/indexing.sql
b/src/test/regress/sql/indexing.sql
index f145384fbc..b0feb1911d 100644
--- a/src/test/regress/sql/indexing.sql
+++ b/src/test/regress/sql/indexing.sql
@@ -1,12 +1,19 @@
-- Creating an index on a partitioned table makes the partitions
-- automatically get the index
create table idxpart (a int, b int, c text) partition by range (a);
+
+-- relhassubclass of a partitioned index is false before creating its partition
+-- it will be set below once partitions get created
+create index check_relhassubclass_of_this on idxpart (a);
+select relhassubclass from pg_class where relname =
'check_relhassubclass_of_this';
+drop index check_relhassubclass_of_this;
+
create table idxpart1 partition of idxpart for values from (0) to (10);
create table idxpart2 partition of idxpart for values from (10) to (100)
partition by range (b);
create table idxpart21 partition of idxpart2 for values from (0) to (100);
create index on idxpart (a);
-select relname, relkind, inhparent::regclass
+select relname, relkind, relhassubclass, inhparent::regclass
from pg_class left join pg_index ix on (indexrelid = oid)
left join pg_inherits on (ix.indexrelid = inhrelid)
where relname like 'idxpart%' order by relname;
@@ -54,7 +61,7 @@ create table idxpart1 partition of idxpart for values from
(0, 0) to (10, 10);
create index on idxpart1 (a, b);
create index on idxpart (a, b);
\d idxpart1
-select relname, relkind, inhparent::regclass
+select relname, relkind, relhassubclass, inhparent::regclass
from pg_class left join pg_index ix on (indexrelid = oid)
left join pg_inherits on (ix.indexrelid = inhrelid)
where relname like 'idxpart%' order by relname;
--
2.11.0
