MariaDB ODBC 连接器性能问题

Question

We try to switch from MySQL 5.0.96 to MariaDB 10.5.9. Move data to MariaDB server was easy but problem is with speed of MariaDB ODBC connector. I tried 3.1.12 with default settings without SSL and our applications (mostly written in Embarcadero RAD Studio) showed very poor performance. When I tried MySQL ODBC connector 8.0.24 everything ran smoothly. Queries through MariaDB's connector was 3-5 times slower. In general query log I found that MariaDB's connector generates a lot of queries to information_scheme.columns table and repeatedly it reads variable TX_ISOLATION. Short extract from general query log - MariaDB connector:

3 Query    SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_VARIABLES WHERE VARIABLE_NAME='TX_ISOLATION'
3 Prepare    select * from stanice
3 Execute    select * from stanice
3 Prepare    SELECT TABLE_SCHEMA AS TABLE_CAT, NULL AS TABLE_SCHEM, TABLE_NAME, COLUMN_NAME, ORDINAL_POSITION KEY_SEQ, 'PRIMARY' PK_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE COLUMN_KEY = 'pri' AND TABLE_SCHEMA LIKE 'unicentrum' AND TABLE_NAME LIKE 'stanice'  ORDER BY TABLE_SCHEMA, TABLE_NAME, ORDINAL_POSITION              
3 Execute    SELECT TABLE_SCHEMA AS TABLE_CAT, NULL AS TABLE_SCHEM, TABLE_NAME, COLUMN_NAME, ORDINAL_POSITION KEY_SEQ, 'PRIMARY' PK_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE COLUMN_KEY = 'pri' AND TABLE_SCHEMA LIKE 'unicentrum' AND TABLE_NAME LIKE 'stanice'  ORDER BY TABLE_SCHEMA, TABLE_NAME, ORDINAL_POSITION
3 Close stmt
3 Reset stmt
3 Query    SELECT VARIABLE_VALUE FROM INFORMATION_SCHEMA.SESSION_VARIABLES WHERE VARIABLE_NAME='TX_ISOLATION'
3 Prepare    SELECT * FROM stanice WHERE Sit_ID = ? ORDER BY Sit_ID, Podsit_ID, ID
3 Execute    SELECT * FROM stanice WHERE Sit_ID = 1 ORDER BY Sit_ID, Podsit_ID, ID
3 Prepare    SELECT TABLE_SCHEMA AS TABLE_CAT, NULL AS TABLE_SCHEM, TABLE_NAME, COLUMN_NAME, ORDINAL_POSITION KEY_SEQ, 'PRIMARY' PK_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE COLUMN_KEY = 'pri' AND TABLE_SCHEMA LIKE 'unicentrum' AND TABLE_NAME LIKE 'stanice'  ORDER BY TABLE_SCHEMA, TABLE_NAME, ORDINAL_POSITION
3 Execute    SELECT TABLE_SCHEMA AS TABLE_CAT, NULL AS TABLE_SCHEM, TABLE_NAME, COLUMN_NAME, ORDINAL_POSITION KEY_SEQ, 'PRIMARY' PK_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE COLUMN_KEY = 'pri' AND TABLE_SCHEMA LIKE 'unicentrum' AND TABLE_NAME LIKE 'stanice'  ORDER BY TABLE_SCHEMA, TABLE_NAME, ORDINAL_POSITION
3 Close stmt
3 Reset stmt

MySQL connector:

3 Query    SELECT @@tx_isolation
...
3 Query    select * from stanice
3 Prepare    SELECT * FROM stanice WHERE Sit_ID = ? ORDER BY Sit_ID, Podsit_ID, ID
3 Execute    SELECT * FROM stanice WHERE Sit_ID = '1' ORDER BY Sit_ID, Podsit_ID, ID
3 Close stmt

I think those "unnecessary" queries are making difference in performance of those connectors. Any ideas what could I do to speed up MariaDB's connector? Thanks

Answer 1

I've opened https://jira.mariadb.org/browse/ODBC-313 for the problem you've described. It would be better to continue there, as at least ODBC trace of the run with both drivers is required to address main issue.