Hi, Alexander, See a couple of questions below: On Oct 04, Alexander Barkov wrote:

revision-id: dcfc60ea2ee (mariadb-10.4.26-28-gdcfc60ea2ee) parent(s): 6c2c825e503 author: Alexander Barkov committer: Alexander Barkov timestamp: 2022-10-03 10:32:42 +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

diff --git a/mysql-test/main/alter_table_debug_aria.test b/mysql-test/main/alter_table_debug_aria.test new file mode 100644 index 00000000000..22df57686e1 --- /dev/null +++ b/mysql-test/main/alter_table_debug_aria.test @@ -0,0 +1,36 @@ +--source include/have_debug.inc +--source include/have_maria.inc + +--echo # +--echo # Start of 10.4 tests +--echo # + +--echo # +--echo # MDEV-28727 ALTER TABLE ALGORITHM=NOCOPY does not work after upgrade +--echo # + +CREATE TABLE t1 (a DOUBLE NOT NULL, KEY(a)) ENGINE=ARIA; +ALTER TABLE t1 MODIFY a DOUBLE NOT NULL DEFAULT 10, ALGORITHM=NOCOPY; +DROP TABLE t1; + +CREATE TABLE t1 (a DOUBLE NOT NULL, KEY(a)) ENGINE=ARIA; +ALTER TABLE t1 MODIFY a DOUBLE NOT NULL DEFAULT 10, ALGORITHM=INSTANT; +DROP TABLE t1; + +SET SESSION debug_dbug='+d,emulate_pre_mdev_20704'; +CREATE TABLE t1 (a DOUBLE NOT NULL, KEY(a)) ENGINE=ARIA;

Why did you add these debug-only tests with the emulate_pre_mdev_20704 hack, when you have perfect non-debug tests with real pre-MDEV-20704 created tables ?

+SET SESSION debug_dbug=''; +--error ER_ALTER_OPERATION_NOT_SUPPORTED +ALTER TABLE t1 MODIFY a DOUBLE NOT NULL DEFAULT 10, ALGORITHM=INSTANT; +DROP TABLE t1; + +SET SESSION debug_dbug='+d,emulate_pre_mdev_20704'; +CREATE TABLE t1 (a DOUBLE NOT NULL, KEY(a)) ENGINE=ARIA; +SET SESSION debug_dbug=''; +--error ER_ALTER_OPERATION_NOT_SUPPORTED +ALTER TABLE t1 MODIFY a DOUBLE NOT NULL DEFAULT 10, ALGORITHM=NOCOPY; +DROP TABLE t1; + +--echo # +--echo # End of 10.4 tests +--echo # diff --git a/sql/sql_table.cc b/sql/sql_table.cc index 2436031200a..c192a4553a9 100644 --- a/sql/sql_table.cc +++ b/sql/sql_table.cc @@ -6748,11 +6753,13 @@ Compare_keys compare_keys_but_name(const KEY *table_key, const KEY *new_key, const KEY *const new_pk, const KEY *const old_pk) { - if (table_key->algorithm != new_key->algorithm) + ulong key_flag_mask= HA_KEYFLAG_MASK | + table->file->key_pack_flags_supported();

I don't understand. You said that these KEY->flags do not affect what the engine does. Why to compare them at all?

+ + if ((table_key->flags & key_flag_mask) != (new_key->flags & key_flag_mask)) return Compare_keys::NotEqual;

- if ((table_key->flags & HA_KEYFLAG_MASK) != - (new_key->flags & HA_KEYFLAG_MASK)) + if (table_key->algorithm != new_key->algorithm) return Compare_keys::NotEqual;

if (table_key->user_defined_key_parts != new_key->user_defined_key_parts)

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