4.8.1 Lakehouse Limitations for all File Formats

• See Section 2.18.9, “Other Limitations” for all HeatWave query related limitations. Before MySQL 8.3.0, not all queries could be accelerated by HeatWave Lakehouse, and a warning or error message was displayed.

• Do not create Lakehouse tables on the source DB in a replicated DB System if any of the replicas are outside MySQL HeatWave on OCI or MySQL HeatWave on AWS. This will cause replication errors.

• It is not possible to dump external tables using the MySQL Shell export utilities, such as dumpInstance(). External tables are not replicated to InnoDB storage and cannot be exported. To export InnoDB data from a Lakehouse enabled database, exclude the external tables with an excludeTables option.

• It is not possible to restore a backup from a Lakehouse enabled DB System to a standalone DB System.

• Lakehouse enabled DB Systems can support a maximum of 512 nodes.

• Before MySQL 8.4.0, Lakehouse does not enforce any specified constraints. For example, Lakehouse does not enforce primary key uniqueness constraints. MySQL 8.4.0 removes this limitation.

• HeatWave Lakehouse does not support the following:

  • DML statements:

    • INSERT

    • UPDATE

    • DELETE

    • REPLACE

  • The CREATE TABLESPACE statement.

  • The following options for the CREATE TABLE statement:

    • AUTOEXTEND_SIZE

    • AVG_ROW_LENGTH

    • CHECKSUM

    • COMPRESS

    • CONNECTION

    • DATADIR

    • DELAY_KEY_WRITE

    • ENCRYPT

    • INDEXDIR

    • INSERT_METHOD

    • KEY_BLOCK_SIZE

    • MAX_ROWS

    • MIN_ROWS

    • PACK_KEYS

    • PASSWORD

    • ROW_FORMAT

    • STATS_AUTO_RECALC

    • STATS_PERSISTENT

    • STATS_SAMPLE_PAGES

    • UNION

  • The default expression for a column definition for the CREATE TABLE statement.

  • Creating temporary tables.

  • Creating AUTO_INCREMENT columns.

  • Creating triggers.

  • Running ANALYZE TABLE.

  • Running ALTER TABLE statements that construct indexes, ADD or DROP columns, or add enforced check constraints.

  • SELECT statements without RAPID as the secondary engine.

  • Hidden columns.

  • Index construction.

  • Keys with column prefixes.

  • Running any statement with a STORAGE clause.

  • The use of CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP or NOW() as a default value for a timestamp column. Also an UPDATE statement with CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP or NOW(). Enable explicit_defaults_for_timestamp to use ALTER TABLE and CREATE TABLE statements with Lakehouse tables that have a timestamp column.

  • The following limitations only apply to DB Systems up to MySQL 8.3.0-u2. MySQL 8.3.0-u2 removes these limitations:

    • Point-in-time-recovery. All DB Systems are created with point-in-time-recovery enabled by default. To enable Lakehouse, disable point-in-time-recovery.

    • High Availability. To enable Lakehouse, disable High Availability or create a standalone DB System for use with Lakehouse.

    • Read Replication.

    • Outbound Replication.

    Note

    When disabling Read Replicas, High Availability, or Outbound Replication on a DB System to enable Lakehouse, it is recommended to wait several minutes before enabling Lakehouse. This allows replication processes to complete their tasks and for the binlog dump threads to stop.