The new patch about it was submitted. https://github.com/MariaDB/server/commit/a40a36d9b9dc8b78171214905dce6d7fe19...

it only tests that there's no error. Tests for locking added.

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+#endif /*MDEV15887*/ what's that?

That piece of code seems to do nothing. But let's discuss it later. Best regards. HF On Sun, Mar 21, 2021 at 7:48 PM Sergei Golubchik wrote:

Hi, Alexey!

On Mar 21, Alexey Botchkov wrote:

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revision-id: 308c28e8a60 (mariadb-10.5.2-393-g308c28e8a60) parent(s): 786bc312b85 author: Alexey Botchkov committer: Alexey Botchkov timestamp: 2021-02-09 00:59:55 +0400 message:

MDEV-15888 Implement FLUSH TABLES tbl_name [, tbl_name] ... WITH READ LOCK for views.

Kind of 'naive' solution that surprisingly worked so trying to understand why.

diff --git a/mysql-test/main/flush-innodb.result b/mysql-test/main/flush-innodb.result index 21e5bda7785..2c886e4f9fc 100644 --- a/mysql-test/main/flush-innodb.result +++ b/mysql-test/main/flush-innodb.result @@ -60,7 +60,7 @@ DROP TABLE export; CREATE VIEW v1 AS SELECT 1; CREATE TEMPORARY TABLE t1 (a INT); FLUSH TABLES v1 FOR EXPORT; -ERROR HY000: 'test.v1' is not of type 'BASE TABLE' +UNLOCK TABLES;

good, but it only tests that there's no error. may be you need to add tests to verify that tables are actually locked?

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FLUSH TABLES t1 FOR EXPORT; ERROR 42S02: Table 'test.t1' doesn't exist FLUSH TABLES non_existent FOR EXPORT; diff --git a/sql/sql_reload.cc b/sql/sql_reload.cc index 8f87d633d19..c146b7693c1 100644 --- a/sql/sql_reload.cc +++ b/sql/sql_reload.cc @@ -543,6 +543,7 @@ bool flush_tables_with_read_lock(THD *thd, TABLE_LIST *all_tables)

if (thd->lex->type & REFRESH_READ_LOCK) { +#ifdef MDEV15887 /* Acquire SNW locks on tables to be flushed. Don't acquire global IX and database-scope IX locks on the tables as this will make @@ -559,6 +560,7 @@ bool flush_tables_with_read_lock(THD *thd, TABLE_LIST *all_tables) for (auto table_list= all_tables; table_list; table_list= table_list->next_global) table_list->mdl_request.ticket= NULL; +#endif /*MDEV15887*/

what's that? btw, the number is MDEV15888

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}

thd->variables.option_bits|= OPTION_TABLE_LOCK;

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