New Features in MySQL 8.0.20 Release

MySQL 8.0.20 has been officially released, bringing both bug fixes and a host of new features for database administrators and developers.

Added the SHOW_ROUTINE privilege, allowing accounts to back up stored routines with minimal permissions.

Improved hash join support: hash join can now replace BNL and supports semi‑joins, anti‑joins, and outer joins.

Introduced new index‑level optimizer hints such as JOIN_INDEX , NO_JOIN_INDEX , GROUP_INDEX , NO_GROUP_INDEX , ORDER_INDEX , NO_ORDER_INDEX , INDEX and NO_INDEX , which can be used with SELECT , UPDATE and DELETE statements.

Performance Schema enhancements reduce memory overhead by dropping global session‑related error statistics and omitting global error info from per‑thread, account, user, or host error summaries.

SQL syntax changes: the INTO clause can now appear at the end of a SELECT statement, and adjustments have been made for UNION ... INTO usage.

X Plugin improvements create an administrative session at startup, enabling configuration access when client connection limits are reached.

BLOB type sorting has been altered to use a packed plugin, delivering noticeable performance gains.

InnoDB doublewrite buffer storage has been moved from the system tablespace to a separate doublewrite file, reducing write latency and increasing throughput.

Binary log transaction compression is now available: enabling it compresses transaction payloads with the ZSTD algorithm and writes them as a single Transaction_payload_event , saving storage space and network bandwidth during replication.

The CHANGE MASTER TO statement gains a new option REQUIRE_TABLE_PRIMARY_KEY_CHECK , allowing replica servers to choose their own primary‑key‑checking strategy.

X protocol messages have supported compression since 8.0.19; starting with 8.0.20, clients can request a specific compression level during negotiation.

For a complete list of changes, refer to the official MySQL online documentation.