[CALCITE-673] Timeout executing joins against MySQL

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Assignee: Unassigned
• Reporter: Julian Hyde
• Created: 07/Apr/15 20:02
• Updated: 22/Feb/19 01:22

Description

Tests JdbcFrontJdbcBackLinqMiddleTest.testJoinGroupByEmpty and testJoinGroupByOrderBy sometimes time out in MySQL running a query like this:

SELECT COUNT(*) AS `EXPR$0`
FROM (SELECT 0 AS `DUMMY`
  FROM (SELECT `customer_id`
    FROM `foodmart`.`customer`) AS `t`
  INNER JOIN (SELECT `customer_id`
    FROM `foodmart`.`sales_fact_1997`) AS `t0` ON `t`.`customer_id` = `t0`.`customer_id`) AS `t1`

Maybe it's too complicated for MySQL to execute efficiently. Disabling those tests for now.