MySQL feature support on Amazon RDS (original) (raw)

RDS for MySQL supports most of the features and capabilities of MySQL. Some features might have limited support or restricted privileges.

You can filter new Amazon RDS features on the What's New with Database? page. For Products, choose Amazon RDS. Then search using keywords such as MySQL 2022.

Note

The following lists are not exhaustive.

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MySQL feature support on Amazon RDS for MySQL major versions

In the following sections, find information about MySQL feature support on Amazon RDS for MySQL major versions:

For information about supported minor versions of Amazon RDS for MySQL, see Supported MySQL minor versions on Amazon RDS.

MySQL 8.4 support on Amazon RDS

Amazon RDS supports the following new features for your DB instances running MySQL version 8.4 or higher.

For a list of all MySQL 8.4 features and changes, see What Is New in MySQL 8.4 since MySQL 8.0 in the MySQL documentation.

For a list of unsupported features, see MySQL features not supported by Amazon RDS.

Supported storage engines for RDS for MySQL

While MySQL supports multiple storage engines with varying capabilities, not all of them are optimized for recovery and data durability. Amazon RDS fully supports the InnoDB storage engine for MySQL DB instances. Amazon RDS features such as Point-In-Time restore and snapshot restore require a recoverable storage engine and are supported for the InnoDB storage engine only. For more information, see MySQL memcached support.

The Federated Storage Engine is currently not supported by Amazon RDS for MySQL.

For user-created schemas, the MyISAM storage engine does not support reliable recovery and can result in lost or corrupt data when MySQL is restarted after a recovery, preventing Point-In-Time restore or snapshot restore from working as intended. However, if you still choose to use MyISAM with Amazon RDS, snapshots can be helpful under some conditions.

Note

System tables in the mysql schema can be in MyISAM storage.

If you want to convert existing MyISAM tables to InnoDB tables, you can use theALTER TABLE command (for example, alter table TABLE_NAME engine=innodb;). Bear in mind that MyISAM and InnoDB have different strengths and weaknesses, so you should fully evaluate the impact of making this switch on your applications before doing so.

MySQL 5.1, 5.5, and 5.6 are no longer supported in Amazon RDS. However, you can restore existing MySQL 5.1, 5.5, and 5.6 snapshots. When you restore a MySQL 5.1, 5.5, or 5.6 snapshot, the DB instance is automatically upgraded to MySQL 5.7.

Using memcached and other options with MySQL on Amazon RDS

Most Amazon RDS DB engines support option groups that allow you to select additional features for your DB instance. RDS for MySQL DB instances support the memcached option, a simple, key-based cache. For more information about memcached and other options, see Options for MySQL DB instances. For more information about working with option groups, see Working with option groups.

InnoDB cache warming for MySQL on Amazon RDS

InnoDB cache warming can provide performance gains for your MySQL DB instance by saving the current state of the buffer pool when the DB instance is shut down, and then reloading the buffer pool from the saved information when the DB instance starts up. This bypasses the need for the buffer pool to "warm up" from normal database use and instead preloads the buffer pool with the pages for known common queries. The file that stores the saved buffer pool information only stores metadata for the pages that are in the buffer pool, and not the pages themselves. As a result, the file does not require much storage space. The file size is about 0.2 percent of the cache size. For example, for a 64 GiB cache, the cache warming file size is 128 MiB. For more information on InnoDB cache warming, see Saving and restoring the buffer pool state in the MySQL documentation.

RDS for MySQL DB instances support InnoDB cache warming. To enable InnoDB cache warming, set the innodb_buffer_pool_dump_at_shutdown and innodb_buffer_pool_load_at_startup parameters to 1 in the parameter group for your DB instance. Changing these parameter values in a parameter group will affect all MySQL DB instances that use that parameter group. To enable InnoDB cache warming for specific MySQL DB instances, you might need to create a new parameter group for those instances. For information on parameter groups, see Parameter groups for Amazon RDS.

InnoDB cache warming primarily provides a performance benefit for DB instances that use standard storage. If you use PIOPS storage, you do not commonly see a significant performance benefit.

Important

If your MySQL DB instance does not shut down normally, such as during a failover, then the buffer pool state will not be saved to disk. In this case, MySQL loads whatever buffer pool file is available when the DB instance is restarted. No harm is done, but the restored buffer pool might not reflect the most recent state of the buffer pool prior to the restart. To ensure that you have a recent state of the buffer pool available to warm the InnoDB cache on startup, we recommend that you periodically dump the buffer pool "on demand."

You can create an event to dump the buffer pool automatically and on a regular interval. For example, the following statement creates an event namedperiodic_buffer_pool_dump that dumps the buffer pool every hour.

CREATE EVENT periodic_buffer_pool_dump 
ON SCHEDULE EVERY 1 HOUR 
DO CALL mysql.rds_innodb_buffer_pool_dump_now();

For more information on MySQL events, see Event syntax in the MySQL documentation.

Dumping and loading the buffer pool on demand

You can save and load the InnoDB cache "on demand."

Inclusive language changes for RDS for MySQL 8.4

RDS for MySQL 8.4 includes changes from the MySQL 8.4 community edition related to keywords and system schemas for inclusive language. For example, the SHOW REPLICA STATUS command replaces SHOW SLAVE STATUS.

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Configuration parameter name changes

The following configuration parameters have new names in RDS for MySQL 8.4.

For compatibility, you can check the parameter names in the mysql client by using either name. You can only use the new names when modifying values in a custom MySQL 8.4 parameter group. For more information, see Default and custom parameter groups.

Name to be removed New or preferred name
init_slave init_replica
log_slave_updates log_replica_updates
log_slow_slave_statements log_slow_replica_statements
rpl_stop_slave_timeout rpl_stop_replica_timeout
skip_slave_start skip_replica_start
slave_checkpoint_group replica_checkpoint_group
slave_checkpoint_period replica_checkpoint_period
slave_compressed_protocol replica_compressed_protocol
slave_exec_mode replica_exec_mode
slave_load_tmpdir replica_load_tmpdir
slave_max_allowed_packet replica_max_allowed_packet
slave_net_timeout replica_net_timeout
slave_parallel_type replica_parallel_type
slave_parallel_workers replica_parallel_workers
slave_pending_jobs_size_max replica_pending_jobs_size_max
slave_preserve_commit_order replica_preserve_commit_order
slave_skip_errors replica_skip_errors
slave_sql_verify_checksum replica_sql_verify_checksum
slave_transaction_retries replica_transaction_retries
slave_type_conversions replica_type_conversions
sql_slave_skip_counter sql_replica_skip_counter
Note

The parameter replica_allow_batching isn't available because Amazon RDS doesn't support NDB clusters.

Stored procedure name changes

The following stored procedures have new names in RDS for MySQL 8.4.

For compatibility, you can use either name in the initial RDS for MySQL 8.4 release. The old procedure names are to be removed in a future release. For more information, seeConfiguring, starting, and stopping binary log (binlog) replication.

Name to be removed New or preferred name
mysql.rds_next_master_log mysql.rds_next_source_log
mysql.rds_reset_external_master mysql.rds_reset_external_source
mysql.rds_set_external_master mysql.rds_set_external_source
mysql.rds_set_external_master_with_auto_position mysql.rds_set_external_source_with_auto_position
mysql.rds_set_external_master_with_delay mysql.rds_set_external_source_with_delay
mysql.rds_set_master_auto_position mysql.rds_set_source_auto_position

MySQL features not supported by Amazon RDS

Amazon RDS doesn't currently support the following MySQL features:

To deliver a managed service experience, Amazon RDS doesn't provide shell access to DB instances. It also restricts access to certain system procedures and tables that require advanced privileges. Amazon RDS supports access to databases on a DB instance using any standard SQL client application. Amazon RDS doesn't allow direct host access to a DB instance by using Telnet, Secure Shell (SSH), or Windows Remote Desktop Connection. When you create a DB instance, you are assigned as db_owner for all databases on that instance, and you have all database-level permissions except for those used for backups. Amazon RDS manages backups for you.