Simplify psql \d's rule for ordering the indexes of a table.

The previous rule was "primary key (if any) first, then other unique
indexes in name order, then all other indexes in name order".
But the preference for unique indexes seems a bit obsolete since the
introduction of exclusion constraints.   It's no longer the case
that unique indexes are the only ones that constrain what data can
be in the table, and it's hard to see what other rationale there is
for separating out unique indexes.  Other new features like the
possibility for some indexes to be INVALID (hence, not constraining
anything) make this even shakier.

Hence, simplify the sort order to be "primary key (if any) first,
then all other indexes in name order".

No documentation change, since this was never documented anyway.
A couple of existing regression test cases change output, though.

Discussion: https://postgr.es/m/[email protected]

3 files changed, 15 insertions, 15 deletions

diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index e687150511b..d621f61c623 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -1925,12 +1925,12 @@ create unique index on anothertab(f4);
 Indexes:
     "anothertab_pkey" PRIMARY KEY, btree (f1)
     "anothertab_f1_f4_key" UNIQUE CONSTRAINT, btree (f1, f4)
-    "anothertab_f2_key" UNIQUE CONSTRAINT, btree (f2)
-    "anothertab_f4_idx" UNIQUE, btree (f4)
     "anothertab_f2_f3_idx" btree (f2, f3)
+    "anothertab_f2_key" UNIQUE CONSTRAINT, btree (f2)
     "anothertab_f3_excl" EXCLUDE USING btree (f3 WITH =)
     "anothertab_f4_excl" EXCLUDE USING btree (f4 WITH =) WHERE (f4 IS NOT NULL)
     "anothertab_f4_excl1" EXCLUDE USING btree (f4 WITH =) WHERE (f5 > 0)
+    "anothertab_f4_idx" UNIQUE, btree (f4)
 
 alter table anothertab alter column f1 type bigint;
 alter table anothertab
@@ -1950,12 +1950,12 @@ alter table anothertab alter column f5 type bigint;
 Indexes:
     "anothertab_pkey" PRIMARY KEY, btree (f1)
     "anothertab_f1_f4_key" UNIQUE CONSTRAINT, btree (f1, f4)
-    "anothertab_f2_key" UNIQUE CONSTRAINT, btree (f2)
-    "anothertab_f4_idx" UNIQUE, btree (f4)
     "anothertab_f2_f3_idx" btree (f2, f3)
+    "anothertab_f2_key" UNIQUE CONSTRAINT, btree (f2)
     "anothertab_f3_excl" EXCLUDE USING btree (f3 WITH =)
     "anothertab_f4_excl" EXCLUDE USING btree (f4 WITH =) WHERE (f4 IS NOT NULL)
     "anothertab_f4_excl1" EXCLUDE USING btree (f4 WITH =) WHERE (f5 > 0)
+    "anothertab_f4_idx" UNIQUE, btree (f4)
 
 drop table anothertab;
 create table another (f1 int, f2 text);
diff --git a/src/test/regress/expected/create_index.out b/src/test/regress/expected/create_index.out
index 5305b53cac9..9305649c113 100644
--- a/src/test/regress/expected/create_index.out
+++ b/src/test/regress/expected/create_index.out
@@ -1374,10 +1374,10 @@ VACUUM FULL concur_heap;
  f1     | text |           |          | 
  f2     | text |           |          | 
 Indexes:
-    "concur_index2" UNIQUE, btree (f1)
-    "concur_index3" UNIQUE, btree (f2) INVALID
     "concur_heap_expr_idx" btree ((f2 || f1))
     "concur_index1" btree (f2, f1)
+    "concur_index2" UNIQUE, btree (f1)
+    "concur_index3" UNIQUE, btree (f2) INVALID
     "concur_index4" btree (f2) WHERE f1 = 'a'::text
     "concur_index5" btree (f2) WHERE f1 = 'x'::text
     "std_index" btree (f2)
@@ -1390,10 +1390,10 @@ REINDEX TABLE concur_heap;
  f1     | text |           |          | 
  f2     | text |           |          | 
 Indexes:
-    "concur_index2" UNIQUE, btree (f1)
-    "concur_index3" UNIQUE, btree (f2)
     "concur_heap_expr_idx" btree ((f2 || f1))
     "concur_index1" btree (f2, f1)
+    "concur_index2" UNIQUE, btree (f1)
+    "concur_index3" UNIQUE, btree (f2)
     "concur_index4" btree (f2) WHERE f1 = 'a'::text
     "concur_index5" btree (f2) WHERE f1 = 'x'::text
     "std_index" btree (f2)
@@ -2115,8 +2115,8 @@ WARNING:  cannot reindex system catalogs concurrently, skipping all
  c2     | text    |           |          | 
 Indexes:
     "concur_reindex_ind1" PRIMARY KEY, btree (c1)
-    "concur_reindex_ind3" UNIQUE, btree (abs(c1))
     "concur_reindex_ind2" btree (c2)
+    "concur_reindex_ind3" UNIQUE, btree (abs(c1))
     "concur_reindex_ind4" btree (c1, c1, c2)
 Referenced by:
     TABLE "concur_reindex_tab2" CONSTRAINT "concur_reindex_tab2_c1_fkey" FOREIGN KEY (c1) REFERENCES concur_reindex_tab(c1)
diff --git a/src/test/regress/expected/replica_identity.out b/src/test/regress/expected/replica_identity.out
index 175ecd28794..739608aab4c 100644
--- a/src/test/regress/expected/replica_identity.out
+++ b/src/test/regress/expected/replica_identity.out
@@ -85,13 +85,13 @@ SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
 Indexes:
     "test_replica_identity_pkey" PRIMARY KEY, btree (id) REPLICA IDENTITY
     "test_replica_identity_expr" UNIQUE, btree (keya, keyb, (3))
+    "test_replica_identity_hash" hash (nonkey)
+    "test_replica_identity_keyab" btree (keya, keyb)
     "test_replica_identity_keyab_key" UNIQUE, btree (keya, keyb)
     "test_replica_identity_nonkey" UNIQUE, btree (keya, nonkey)
     "test_replica_identity_partial" UNIQUE, btree (keya, keyb) WHERE keyb <> '3'::text
     "test_replica_identity_unique_defer" UNIQUE CONSTRAINT, btree (keya, keyb) DEFERRABLE
     "test_replica_identity_unique_nondefer" UNIQUE CONSTRAINT, btree (keya, keyb)
-    "test_replica_identity_hash" hash (nonkey)
-    "test_replica_identity_keyab" btree (keya, keyb)
 
 -- succeed, nondeferrable unique constraint over nonnullable cols
 ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_unique_nondefer;
@@ -115,13 +115,13 @@ SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
 Indexes:
     "test_replica_identity_pkey" PRIMARY KEY, btree (id)
     "test_replica_identity_expr" UNIQUE, btree (keya, keyb, (3))
+    "test_replica_identity_hash" hash (nonkey)
+    "test_replica_identity_keyab" btree (keya, keyb)
     "test_replica_identity_keyab_key" UNIQUE, btree (keya, keyb) REPLICA IDENTITY
     "test_replica_identity_nonkey" UNIQUE, btree (keya, nonkey)
     "test_replica_identity_partial" UNIQUE, btree (keya, keyb) WHERE keyb <> '3'::text
     "test_replica_identity_unique_defer" UNIQUE CONSTRAINT, btree (keya, keyb) DEFERRABLE
     "test_replica_identity_unique_nondefer" UNIQUE CONSTRAINT, btree (keya, keyb)
-    "test_replica_identity_hash" hash (nonkey)
-    "test_replica_identity_keyab" btree (keya, keyb)
 
 SELECT count(*) FROM pg_index WHERE indrelid = 'test_replica_identity'::regclass AND indisreplident;
  count 
@@ -163,13 +163,13 @@ SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
 Indexes:
     "test_replica_identity_pkey" PRIMARY KEY, btree (id)
     "test_replica_identity_expr" UNIQUE, btree (keya, keyb, (3))
+    "test_replica_identity_hash" hash (nonkey)
+    "test_replica_identity_keyab" btree (keya, keyb)
     "test_replica_identity_keyab_key" UNIQUE, btree (keya, keyb)
     "test_replica_identity_nonkey" UNIQUE, btree (keya, nonkey)
     "test_replica_identity_partial" UNIQUE, btree (keya, keyb) WHERE keyb <> '3'::text
     "test_replica_identity_unique_defer" UNIQUE CONSTRAINT, btree (keya, keyb) DEFERRABLE
     "test_replica_identity_unique_nondefer" UNIQUE CONSTRAINT, btree (keya, keyb)
-    "test_replica_identity_hash" hash (nonkey)
-    "test_replica_identity_keyab" btree (keya, keyb)
 Replica Identity: FULL
 
 ALTER TABLE test_replica_identity REPLICA IDENTITY NOTHING;