[MDEV-17035] Support ALGORITHM=NOCOPY for CHANGE virtual column expression Created: 2018-08-22  Updated: 2019-04-20

Status: Open
Project: MariaDB Server
Component/s: Storage Engine - InnoDB
Fix Version/s: None

Type: Task Priority: Major
Reporter: Marko Mäkelä Assignee: Marko Mäkelä
Resolution: Unresolved Votes: 1
Labels: online-ddl

Issue Links:
Blocks
is blocked by MDEV-16291 Allow ALGORITHM=NOCOPY for most ALTER... Open
Relates
relates to MDEV-14341 Allow LOCK=NONE in table-rebuilding A... Open
relates to MDEV-17468 Avoid table rebuild on operations on ... Stalled

 Description   

Currently, the ALTER TABLE operation ALTER_STORED_GCOL_EXPR (changing the expression of a generated stored column, or materialized virtual column) is only supported by ALGORITHM=COPY, which does a full rebuild of the table.

We could support the operation with ALGORITHM=NOCOPY by validating all data and executing UPDATE of the data. Concurrent non-locking MVCC reads would be possible, but concurrent writes to the table could lead to locking conflicts.
Generated at Thu Feb 08 08:33:25 UTC 2024 using Jira 8.20.16#820016-sha1:9d11dbea5f4be3d4cc21f03a88dd11d8c8687422.