diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c
index 617270f101d4a62f6dd4f188c826a5509ceb7dc7..91b12dc90e7b2870baa762f6194eb7268b025cfe 100644
--- a/src/bin/pg_upgrade/check.c
+++ b/src/bin/pg_upgrade/check.c
@@ -108,6 +108,14 @@ check_and_dump_old_cluster(bool live_check)
if (GET_MAJOR_VERSION(old_cluster.major_version) <= 1100)
check_for_tables_with_oids(&old_cluster);
+ /*
+ * PG 12 changed the 'sql_identifier' type storage to be based on name,
+ * not varchar, which breaks on-disk format for existing data. So we need
+ * to prevent upgrade when used in user objects (tables, indexes, ...).
+ */
+ if (GET_MAJOR_VERSION(old_cluster.major_version) <= 1100)
+ old_11_check_for_sql_identifier_data_type_usage(&old_cluster);
+
/*
* Pre-PG 10 allowed tables with 'unknown' type columns and non WAL logged
* hash indexes
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index 5d31750d867498f37bed3b425de472e45a867117..63574b51bc7bb4a736a1281e044466be02af7fd9 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -458,6 +458,8 @@ void old_9_6_check_for_unknown_data_type_usage(ClusterInfo *cluster);
void old_9_6_invalidate_hash_indexes(ClusterInfo *cluster,
bool check_mode);
+void old_11_check_for_sql_identifier_data_type_usage(ClusterInfo *cluster);
+
/* parallel.c */
void parallel_exec_prog(const char *log_file, const char *opt_log_file,
const char *fmt,...) pg_attribute_printf(3, 4);
diff --git a/src/bin/pg_upgrade/version.c b/src/bin/pg_upgrade/version.c
index 10cb362e0929dd7e7a4fa47b25e9bb3de838bf42..60a1025c3ec292c3e1bc342e82477adfeeebe60d 100644
--- a/src/bin/pg_upgrade/version.c
+++ b/src/bin/pg_upgrade/version.c
@@ -399,3 +399,122 @@ old_9_6_invalidate_hash_indexes(ClusterInfo *cluster, bool check_mode)
else
check_ok();
}
+
+/*
+ * old_11_check_for_sql_identifier_data_type_usage()
+ * 11 -> 12
+ * In 12, the sql_identifier data type was switched from name to varchar,
+ * which does affect the storage (name is by-ref, but not varlena). This
+ * means user tables using sql_identifier for columns are broken because
+ * the on-disk format is different.
+ *
+ * We need to check all objects that might store sql_identifier on disk,
+ * i.e. tables, matviews and indexes. Also check composite types in case
+ * they are used in this context.
+ */
+void
+old_11_check_for_sql_identifier_data_type_usage(ClusterInfo *cluster)
+{
+ int dbnum;
+ FILE *script = NULL;
+ bool found = false;
+ char output_path[MAXPGPATH];
+
+ prep_status("Checking for invalid \"sql_identifier\" user columns");
+
+ snprintf(output_path, sizeof(output_path), "tables_using_sql_identifier.txt");
+
+ for (dbnum = 0; dbnum < cluster->dbarr.ndbs; dbnum++)
+ {
+ PGresult *res;
+ bool db_used = false;
+ int ntups;
+ int rowno;
+ int i_nspname,
+ i_relname,
+ i_attname;
+ DbInfo *active_db = &cluster->dbarr.dbs[dbnum];
+ PGconn *conn = connectToServer(cluster, active_db->db_name);
+
+ /*
+ * We need the recursive CTE because the sql_identifier may be wrapped
+ * either in a domain or composite type, or both (in arbitrary order).
+ */
+ res = executeQueryOrDie(conn,
+ "WITH RECURSIVE oids AS ( "
+ /* the sql_identifier type itself */
+ " SELECT 'information_schema.sql_identifier'::regtype AS oid "
+ " UNION ALL "
+ " SELECT * FROM ( "
+ /* domains on the type */
+ " WITH x AS (SELECT oid FROM oids) "
+ " SELECT t.oid FROM pg_catalog.pg_type t, x WHERE typbasetype = x.oid AND typtype = 'd' "
+ " UNION "
+ /* composite types containing the type */
+ " SELECT t.oid FROM pg_catalog.pg_type t, pg_catalog.pg_class c, pg_catalog.pg_attribute a, x "
+ " WHERE t.typtype = 'c' AND "
+ " t.oid = c.reltype AND "
+ " c.oid = a.attrelid AND "
+ " NOT a.attisdropped AND "
+ " a.atttypid = x.oid "
+ " ) foo "
+ ") "
+ "SELECT n.nspname, c.relname, a.attname "
+ "FROM pg_catalog.pg_class c, "
+ " pg_catalog.pg_namespace n, "
+ " pg_catalog.pg_attribute a "
+ "WHERE c.oid = a.attrelid AND "
+ " NOT a.attisdropped AND "
+ " a.atttypid IN (SELECT oid FROM oids) AND "
+ " c.relkind IN ("
+ CppAsString2(RELKIND_RELATION) ", "
+ CppAsString2(RELKIND_MATVIEW) ", "
+ CppAsString2(RELKIND_INDEX) ") AND "
+ " c.relnamespace = n.oid AND "
+ /* exclude possible orphaned temp tables */
+ " n.nspname !~ '^pg_temp_' AND "
+ " n.nspname !~ '^pg_toast_temp_' AND "
+ " n.nspname NOT IN ('pg_catalog', 'information_schema')");
+
+ ntups = PQntuples(res);
+ i_nspname = PQfnumber(res, "nspname");
+ i_relname = PQfnumber(res, "relname");
+ i_attname = PQfnumber(res, "attname");
+ for (rowno = 0; rowno < ntups; rowno++)
+ {
+ found = true;
+ if (script == NULL && (script = fopen_priv(output_path, "w")) == NULL)
+ pg_fatal("could not open file \"%s\": %s\n", output_path,
+ strerror(errno));
+ if (!db_used)
+ {
+ fprintf(script, "Database: %s\n", active_db->db_name);
+ db_used = true;
+ }
+ fprintf(script, " %s.%s.%s\n",
+ PQgetvalue(res, rowno, i_nspname),
+ PQgetvalue(res, rowno, i_relname),
+ PQgetvalue(res, rowno, i_attname));
+ }
+
+ PQclear(res);
+
+ PQfinish(conn);
+ }
+
+ if (script)
+ fclose(script);
+
+ if (found)
+ {
+ pg_log(PG_REPORT, "fatal\n");
+ pg_fatal("Your installation contains the \"sql_identifier\" data type in user tables\n"
+ "and/or indexes. The on-disk format for this data type has changed, so this\n"
+ "cluster cannot currently be upgraded. You can remove the problem tables or\n"
+ "change the data type to \"name\" and restart the upgrade.\n"
+ "A list of the problem columns is in the file:\n"
+ " %s\n\n", output_path);
+ }
+ else
+ check_ok();
+}