WL#15684 System variable to select JSON EXPLAIN format

Post-push fix: broken test on rebase

Change-Id: Ib0361109bb764ddc606d31ede90d73d1643380b4

Author: mbremyk

mysql-test/r/all_persisted_variables.result

@@ -46,17 +46,17 @@ include/assert.inc [Expect 500+ variables in the table. Due to open Bugs, we are
 
 # Test SET PERSIST
 
-include/assert.inc [Expect 444 persisted variables in the table.]
+include/assert.inc [Expect 445 persisted variables in the table.]
 
 ************************************************************
 * 3. Restart server, it must preserve the persisted variable
 *    settings. Verify persisted configuration.
 ************************************************************
 # restart
 
-include/assert.inc [Expect 444 persisted variables in persisted_variables table.]
-include/assert.inc [Expect 444 persisted variables shown as PERSISTED in variables_info table.]
-include/assert.inc [Expect 444 persisted variables with matching peristed and global values.]
+include/assert.inc [Expect 445 persisted variables in persisted_variables table.]
+include/assert.inc [Expect 445 persisted variables shown as PERSISTED in variables_info table.]
+include/assert.inc [Expect 445 persisted variables with matching peristed and global values.]
 
 ************************************************************
 * 4. Test RESET PERSIST IF EXISTS. Verify persisted variable

mysql-test/t/all_persisted_variables.test

@@ -50,7 +50,7 @@ let $total_global_vars=`SELECT COUNT(*)
    WHERE variable_name NOT LIKE 'ndb_%'
    AND variable_name NOT LIKE 'debug_%'
    AND variable_name NOT LIKE '%telemetry%'`;
-let $total_persistent_vars=444;
+let $total_persistent_vars=445;
 
 --echo ***************************************************************
 --echo * 0. Verify that variables present in performance_schema.global