From d96b4b4d3e999609608a52cb4bcf7ca7ff593920 Mon Sep 17 00:00:00 2001
From: Ishjaap Singh <ishjaap.singh07@gmail.com>
Date: Wed, 4 Nov 2026 20:17:11 +0000
Subject: [PATCH v1] psql: Don't offer partitioned tables after CREATE INDEX
 CONCURRENTLY

Tab completion after CREATE INDEX CONCURRENTLY [name] ON offered the
same relations as plain CREATE INDEX, including partitioned tables.
CREATE INDEX CONCURRENTLY is not supported on partitioned tables, so
choosing one always fails:

    CREATE INDEX CONCURRENTLY ON parted (a);
    ERROR:  cannot create index on partitioned table "parted" concurrently

Use a separate list without partitioned tables after CONCURRENTLY.
Plain tables, materialized views and leaf partitions are still offered.
---
 src/bin/psql/t/010_tab_completion.pl | 41 ++++++++++++++++++++++++++++
 src/bin/psql/tab-complete.in.c       | 24 ++++++++++++++--
 2 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/src/bin/psql/t/010_tab_completion.pl b/src/bin/psql/t/010_tab_completion.pl
index 1d2e5f5b92a..1a1075a60aa 100644
--- a/src/bin/psql/t/010_tab_completion.pl
+++ b/src/bin/psql/t/010_tab_completion.pl
@@ -347,6 +347,47 @@ check_completion(
 
 clear_query();
 
+# CREATE INDEX CONCURRENTLY doesn't support partitioned tables, so they
+# must not be offered after it.  The two tables share a prefix: if only the
+# plain one is offered, "cic_p" completes to it.
+$node->safe_psql('postgres',
+		"CREATE TABLE cic_part (f1 int) PARTITION BY RANGE (f1);\n"
+	  . "CREATE TABLE cic_plain (f1 int);\n");
+
+# "index" is a valid index name, and must not make the command look like a
+# plain CREATE INDEX.
+foreach my $cmd (
+	'CREATE INDEX CONCURRENTLY ON',
+	'CREATE INDEX CONCURRENTLY cic_idx ON',
+	'CREATE INDEX CONCURRENTLY index ON',
+	'CREATE UNIQUE INDEX CONCURRENTLY ON',
+	'CREATE UNIQUE INDEX CONCURRENTLY index ON')
+{
+	check_completion("$cmd cic_p\t", qr/cic_plain /,
+		"$cmd does not offer partitioned tables");
+	clear_query();
+
+	# A prefix that matches only the partitioned table must not complete.
+	# The X typed after the tab shows that the word was left alone.
+	check_completion("$cmd cic_pa\tX",
+		qr/cic_pa\a?X/, "$cmd does not complete a partitioned table");
+	clear_query();
+}
+
+# Without CONCURRENTLY, partitioned tables are fine.
+foreach my $cmd (
+	'CREATE INDEX ON',
+	'CREATE INDEX cic_idx ON',
+	'CREATE INDEX index ON',
+	'CREATE UNIQUE INDEX ON')
+{
+	check_completion(
+		"$cmd cic_p\t\t",
+		qr/cic_part +cic_plain/,
+		"$cmd offers partitioned tables");
+	clear_query();
+}
+
 # check VersionedQuery infrastructure
 check_completion(
 	"DROP PUBLIC\t \t\t",
diff --git a/src/bin/psql/tab-complete.in.c b/src/bin/psql/tab-complete.in.c
index 96de78cd087..334f0372b9b 100644
--- a/src/bin/psql/tab-complete.in.c
+++ b/src/bin/psql/tab-complete.in.c
@@ -930,6 +930,17 @@ static const SchemaQuery Query_for_list_of_indexables = {
 	.result = "c.relname",
 };
 
+/* Relations supporting CREATE INDEX CONCURRENTLY */
+static const SchemaQuery Query_for_list_of_concurrent_indexables = {
+	.catname = "pg_catalog.pg_class c",
+	.selcondition =
+	"c.relkind IN (" CppAsString2(RELKIND_RELATION) ", "
+	CppAsString2(RELKIND_MATVIEW) ")",
+	.viscondition = "pg_catalog.pg_table_is_visible(c.oid)",
+	.namespace = "c.relnamespace",
+	.result = "c.relname",
+};
+
 /*
  * Relations supporting VACUUM are currently same as those supporting
  * indexing.
@@ -3548,10 +3559,17 @@ match_previous_words(int pattern_id,
 
 	/*
 	 * Complete ... INDEX|CONCURRENTLY [<name>] ON with a list of relations
-	 * that indexes can be created on
+	 * that indexes can be created on.  CREATE INDEX CONCURRENTLY doesn't
+	 * support partitioned tables, so leave those out after CONCURRENTLY. The
+	 * plain rule must not match any CONCURRENTLY form (not even one with an
+	 * index named "index"), or it would offer partitioned tables anyway
+	 * whenever the CONCURRENTLY rule finds no match.
 	 */
-	else if (TailMatches("INDEX|CONCURRENTLY", MatchAny, "ON") ||
-			 TailMatches("INDEX|CONCURRENTLY", "ON"))
+	else if (TailMatches("CONCURRENTLY", MatchAny, "ON") ||
+			 TailMatches("CONCURRENTLY", "ON"))
+		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_concurrent_indexables);
+	else if (TailMatches("CREATE|UNIQUE", "INDEX", MatchAnyExcept("CONCURRENTLY"), "ON") ||
+			 TailMatches("CREATE|UNIQUE", "INDEX", "ON"))
 		COMPLETE_WITH_SCHEMA_QUERY(Query_for_list_of_indexables);
 
 	/*
-- 
2.43.0