Hi, Alexander, ok to push! On Oct 21, Alexander Barkov wrote:

revision-id: 99dcf061c8c (mariadb-10.4.26-55-g99dcf061c8c) parent(s): 1be451ca797 author: Alexander Barkov committer: Alexander Barkov timestamp: 2022-10-21 14:31:02 +0400 message:

MDEV-29481 mariadb-upgrade prints confusing statement

This is a new version of the patch instead of the reverted:

MDEV-28727 ALTER TABLE ALGORITHM=NOCOPY does not work after upgrade

Ignore the difference in key packing flags HA_BINARY_PACK_KEY and HA_PACK_KEY during ALTER to allow ALGORITHM=INSTANT and ALGORITHM=NOCOPY in more cases.

If for some reasons (e.g. due to a bug fix such as MDEV-20704) these cumulative (over all segments) flags in KEY::flags are different for the old and new table inside compare_keys_but_name(), the difference in HA_BINARY_PACK_KEY and HA_PACK_KEY in KEY::flags is not really important:

MyISAM and Aria can handle such cases well: per-segment flags are stored in MYI and MAI files anyway and they are read during ha_myisam::open() ha_maria::open() time. So indexes get opened with correct per-segment flags that were calculated during the table CREATE time, no matter what the old (CREATE time) and new (ALTER TIME) per-index compression flags are, and no matter if they are equal or not.

All other engine ignore key compression flags, so this change is safe for other engines as well.

Regards, Sergei VP of MariaDB Server Engineering and security@mariadb.org