Other options are preserved by ALTER (and CLUSTER ON is and most obviously
should be preserved by CLUSTER's rewrite), so I think (SET) CLUSTER should be
preserved by ALTER, too.
As far as I can see, this should be the responsibility of something in the
vicinity of ATPostAlterTypeParse/RememberIndexForRebuilding.
Attach patch sketches a fix.
ts=# SET client_min_messages=debug; DROP TABLE t; CREATE TABLE t(i int); CREATE
INDEX ON t(i)WITH(fillfactor=11, vacuum_cleanup_index_scale_factor=12); CLUSTER
t USING t_i_key; ALTER TABLE t ALTER i TYPE bigint; \d t
SET
DEBUG: drop auto-cascades to type t
DEBUG: drop auto-cascades to type t[]
DEBUG: drop auto-cascades to index t_i_idx
DROP TABLE
CREATE TABLE
DEBUG: building index "t_i_idx" on table "t" serially
CREATE INDEX
ERROR: index "t_i_key" for table "t" does not exist
DEBUG: rewriting table "t"
DEBUG: building index "t_i_idx" on table "t" serially
DEBUG: drop auto-cascades to type pg_temp_3091172777
DEBUG: drop auto-cascades to type pg_temp_3091172777[]
ALTER TABLE
Table "public.t"
Column | Type | Collation | Nullable | Default
--------+--------+-----------+----------+---------
i | bigint | | |
Indexes:
"t_i_idx" btree (i) WITH (fillfactor='11',
vacuum_cleanup_index_scale_factor='12')
>From f235a691722a464059358cd6b1d744f75d7bf92f Mon Sep 17 00:00:00 2001
From: Justin Pryzby <pryz...@telsasoft.com>
Date: Sun, 2 Feb 2020 09:49:57 -0600
Subject: [PATCH v1] preserve CLUSTER ON during ALTER TABLE
---
src/backend/commands/tablecmds.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index f599393..c4e6cbd 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -11616,6 +11616,7 @@ RememberIndexForRebuilding(Oid indoid, AlteredTableInfo *tab)
}
else
{
+ Relation indrel;
/* OK, capture the index's existing definition string */
char *defstring = pg_get_indexdef_string(indoid);
@@ -11623,6 +11624,18 @@ RememberIndexForRebuilding(Oid indoid, AlteredTableInfo *tab)
indoid);
tab->changedIndexDefs = lappend(tab->changedIndexDefs,
defstring);
+ /* Preserve CLUSTER ON if set */
+ indrel = index_open(indoid, AccessShareLock);
+ if (indrel->rd_index->indisclustered) {
+ char buf[3*NAMEDATALEN + 24];
+ sprintf(buf, "ALTER TABLE %s CLUSTER ON %s",
+ get_rel_name(tab->relid), get_rel_name(indoid)); // XXX: schema
+ tab->changedIndexOids = lappend_oid(tab->changedIndexOids,
+ indoid);
+ tab->changedIndexDefs = lappend(tab->changedIndexDefs,
+ pstrdup(buf));
+ }
+ index_close(indrel, NoLock);
}
}
}
@@ -11901,6 +11914,11 @@ ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId, char *cmd,
* the new table definition.
*/
}
+ else if (cmd->subtype == AT_ClusterOn)
+ {
+ tab->subcmds[AT_PASS_OLD_INDEX] =
+ lappend(tab->subcmds[AT_PASS_OLD_INDEX], cmd);
+ }
else
elog(ERROR, "unexpected statement subtype: %d",
(int) cmd->subtype);
--
2.7.4
