Server System Variables Type Integer Default Value (64-bit platforms) 18446744073709551615 Default Value (32-bit platforms) 4294967295 Minimum Value 10000000 Maximum Value (64-bit platforms) 18446744073709551615 Maximum Value (32-bit platforms) 4294967295 Command-Line Format --partial-revokes[={OFF|ON}] Introduced 8.0.16 System Variable partial_revokes Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Boolean Default Value OFF  (if partial revokes do not exist) ON  (if partial revokes exist) The maximum amount of memory available to the parser. The default value places no limit on memory available. The value can be reduced to protect against out-of-memory situations caused by parsing long or complex SQL statements. Enabling this variable makes it possible to revoke privileges partially. Specifically, for users who have privileges at the global level,  partial_revokes  enables privileges for specific schemas to be revoked while leaving the privileges in place for other schemas. For example, a user who has the global  UPDATE privilege can be restricted from exercising this privilege on the  mysql  system schema. (Or, stated another way, the user is enabled to exercise the  UPDATE  privilege on all schemas except the  mysql schema.) In this sense, the user’s global  UPDATE  privilege is partially revoked. Once enabled,  partial_revokes  cannot be disabled if any account has privilege restrictions. If any such account exists, disabling  partial_revokes  fails: To disable  partial_revokes  in this case, first modify each account that has partially revoked privileges, either by re-granting the privileges or by removing the account. For more information, including instructions for removing partial revokes, see Section 6.2.12, “Privilege Restriction Using Partial Revokes” . 855 •For attempts to disable  partial_revokes  at runtime, an error occurs and the  partial_revokes value remains unchanged. • password_history •For attempts to disable  partial_revokes  at startup, the server logs an error message and enables partial_revokes . • partial_revokes Command-Line Format --password-history=# System Variable password_history