pg_restore: add --no-globals option to skip globals

This is a followup to commit 763aaa06f0 Add non-text output formats to
pg_dumpall.

Add a --no-globals option to pg_restore that skips restoring global
objects (roles and tablespaces) when restoring from a pg_dumpall
archive.  When -C/--create is not specified, databases that do not
already exist on the target server are also skipped.

This is useful when restoring only specific databases from a pg_dumpall
archive without needing the global objects to be restored first.

Author: Mahendra Singh Thalor <mahi6run@gmail.com>

With small tweaks by me.

Discussion: https://postgr.es/m/CAKYtNArdcc5kx1MdTtTKFNYiauo3=zCA-NB0LmBCW-RU_kSb3A@mail.gmail.com

doc/src/sgml/ref/pg_restore.sgml

@@ -294,7 +294,23 @@ PostgreSQL documentation
         <option>--exit-on-error</option>,
         <option>--single-transaction</option>,
         <option>--clean</option>, or
-        <option>--transaction-size</option>.
+        <option>--transaction-size</option>,
+        <option>--no-globals</option>.
+       </para>
+      </listitem>
+     </varlistentry>
+
+     <varlistentry>
+      <term><option>--no-globals</option></term>
+      <listitem>
+       <para>
+        Do not restore global objects (roles and tablespaces).  When
+        <option>-C</option>/<option>--create</option> is not specified,
+        databases that do not already exist on the target server are skipped.
+       </para>
+       <para>
+        This option is only relevant when restoring from a non-plain-text
+        archive made using <application>pg_dumpall</application>.
        </para>
       </listitem>
      </varlistentry>

src/bin/pg_dump/pg_restore.c

@@ -107,6 +107,7 @@ main(int argc, char **argv)
 	static int	no_schema = 0;
 	static int	no_security_labels = 0;
 	static int	no_statistics = 0;
+	static int	no_globals = 0;
 	static int	no_subscriptions = 0;
 	static int	strict_names = 0;
 	static int	statistics_only = 0;
@@ -164,6 +165,7 @@ main(int argc, char **argv)
 		{"no-publications", no_argument, &no_publications, 1},
 		{"no-schema", no_argument, &no_schema, 1},
 		{"no-security-labels", no_argument, &no_security_labels, 1},
+		{"no-globals", no_argument, &no_globals, 1},
 		{"no-subscriptions", no_argument, &no_subscriptions, 1},
 		{"no-statistics", no_argument, &no_statistics, 1},
 		{"statistics", no_argument, &with_statistics, 1},
@@ -489,6 +491,10 @@ main(int argc, char **argv)
 		pg_fatal("options %s and %s cannot be used together",
 				 "--statistics", "-g/--globals-only");
 
+	if (no_globals && globals_only)
+		pg_fatal("options %s and %s cannot be used together",
+				 "--no-globals", "-g/--globals-only");
+
 	/*
 	 * -C is not compatible with -1, because we can't create a database inside
 	 * a transaction block.
@@ -614,9 +620,10 @@ main(int argc, char **argv)
 
 		/*
 		 * To restore from a pg_dumpall archive, -C (create database) option
-		 * must be specified unless we are only restoring globals.
+		 * must be specified unless we are only restoring globals or we are
+		 * skipping globals.
 		 */
-		if (!globals_only && opts->createDB != 1)
+		if (!no_globals && !globals_only && opts->createDB != 1)
 		{
 			pg_log_error("option %s must be specified when restoring an archive created by pg_dumpall",
 						 "-C/--create");
@@ -626,13 +633,16 @@ main(int argc, char **argv)
 		}
 
 		/*
-		 * Always restore global objects, even if --exclude-database results
+		 * Restore global objects, even if --exclude-database results in zero
-		 * in zero databases to process. If 'globals-only' is set, exit
+		 * databases to process. If 'globals-only' is set, exit immediately.
-		 * immediately.
 		 */
 		snprintf(global_path, MAXPGPATH, "%s/toc.glo", inputFileSpec);
 
-		n_errors = restore_global_objects(global_path, tmpopts);
+		if (!no_globals)
+			n_errors = restore_global_objects(global_path, tmpopts);
+		else
+			pg_log_info("skipping restore of global objects because %s was specified",
+						"--no-globals");
 
 		if (globals_only)
 			pg_log_info("database restoring skipped because option %s was specified",
@@ -829,6 +839,7 @@ usage(const char *progname)
 	printf(_("  --no-security-labels         do not restore security labels\n"));
 	printf(_("  --no-statistics              do not restore statistics\n"));
 	printf(_("  --no-subscriptions           do not restore subscriptions\n"));
+	printf(_("  --no-globals                 do not restore global objects (roles and tablespaces)\n"));
 	printf(_("  --no-table-access-method     do not restore table access methods\n"));
 	printf(_("  --no-tablespaces             do not restore tablespace assignments\n"));
 	printf(_("  --restrict-key=RESTRICT_KEY  use provided string as psql \\restrict key\n"));
@@ -1349,6 +1360,13 @@ restore_all_databases(const char *inputFileSpec,
 			}
 			else
 			{
+				if (!tmpopts->createDB)
+				{
+					pg_log_info("skipping restore of database \"%s\": database does not exist and %s was not specified",
+								dbidname->str, "-C/--create");
+					continue;
+				}
+
 				/* We'll have to create it */
 				tmpopts->createDB = 1;
 				tmpopts->cparams.dbname = connected_db;

src/bin/pg_dump/t/001_basic.pl

@@ -255,9 +255,13 @@ command_fails_like(
 	'pg_dumpall: --restrict-key can only be used with plain dump format');
 
 command_fails_like(
-	[ 'pg_dumpall', '--format', 'd', '--globals-only', '--clean', '-f', 'dumpfile' ],
+	[
+		'pg_dumpall', '--format', 'd', '--globals-only',
+		'--clean', '-f', 'dumpfile'
+	],
 	qr/\Qpg_dumpall: error: options --clean and -g\/--globals-only cannot be used together in non-text dump\E/,
-	'pg_dumpall: --clean and -g/--globals-only cannot be used together in non-text dump');
+	'pg_dumpall: --clean and -g/--globals-only cannot be used together in non-text dump'
+);
 
 command_fails_like(
 	[ 'pg_dumpall', '--format', 'd' ],
@@ -299,4 +303,12 @@ command_fails_like(
 	qr/\Qpg_restore: error: option -g\/--globals-only can be used only when restoring an archive created by pg_dumpall\E/,
 	'When option --globals-only is used in pg_restore with the dump of pg_dump'
 );
+
+command_fails_like(
+	[
+		'pg_restore', '--globals-only', '--no-globals', '-d', 'xxx',
+		'dumpdir'
+	],
+	qr/\Qpg_restore: error: options --no-globals and -g\/--globals-only cannot be used together\E/,
+	'options --no-globals and --globals-only cannot be used together');
 done_testing();

src/bin/pg_dump/t/007_pg_dumpall.pl

@@ -299,6 +299,24 @@ my %pgdumpall_runs = (
 		like => qr/
             ^\s*\QCREATE ROLE dumpall;\E\s*\n
 			/xm
+	},
+
+	restore_no_globals => {
+		setup_sql => "CREATE TABLE no_globals_test(a int, b text);
+		INSERT INTO no_globals_test VALUES (1, 'hello'), (2, 'world');",
+		dump_cmd => [
+			'pg_dumpall',
+			'--format' => 'directory',
+			'--file' => "$tempdir/restore_no_globals",
+		],
+		restore_cmd => [
+			'pg_restore', '-C', '--no-globals',
+			'--format' => 'directory',
+			'--file' => "$tempdir/restore_no_globals.sql",
+			"$tempdir/restore_no_globals",
+		],
+		like => qr/^\n\QCOPY public.no_globals_test (a, b) FROM stdin;\E/xm,
+		unlike => qr/^\QCREATE ROLE dumpall;\E/xm,
 	},);
 
 # First execute the setup_sql
@@ -578,7 +596,8 @@ like(
 	'map.dat contains expected preamble');
 
 # verify commenting out a line in map.dat skips that database
-$node->safe_psql($run_db, 'CREATE DATABASE comment_test_db;
+$node->safe_psql(
+	$run_db, 'CREATE DATABASE comment_test_db;
 \c comment_test_db
 CREATE TABLE comment_test_table (id int);');