[MCOL-3766] EXPLAIN gives error every other try Created: 2020-02-05  Updated: 2022-10-25  Resolved: 2020-02-12

Status: Closed
Project: MariaDB ColumnStore
Component/s: MDB Plugin
Affects Version/s: 1.4.3
Fix Version/s: 1.4.3

Type: Bug Priority: Major
Reporter: David Hall (Inactive) Assignee: Daniel Lee (Inactive)
Resolution: Fixed Votes: 0
Labels: None

Issue Links:
Relates
relates to MCOL-3689 SELECT executed after EXPLAIN returns... Closed
Sprint: 2020-2

 Description   

The following sequence:

CREATE TABLE t1 (a int) engine=columnstore;
MariaDB [tpch1]> EXPLAIN SELECT a FROM t1 GROUP BY a HAVING 1 != 1 AND a > 1;
ERROR 1815 (HY000): Internal error: Unknown error
MariaDB [tpch1]> EXPLAIN SELECT a FROM t1 GROUP BY a HAVING 1 != 1 AND a > 1;
-----------------------------------------------------------------+

id select_type table type possible_keys key key_len ref rows Extra

-----------------------------------------------------------------+

1 PUSHED SELECT NULL NULL NULL NULL NULL NULL NULL NULL

-----------------------------------------------------------------+
1 row in set (0.025 sec)

 Comments   
Comment by Roman [ 2020-02-10 ]

Plz review both plugin change and regression suite change.

Comment by Daniel Lee (Inactive) [ 2020-02-12 ]

Build tested: 1.4.3-1 BB nightly

Engine commit: 8588678

MariaDB [mytest]> CREATE TABLE t1 (a int) engine=columnstore;
Query OK, 0 rows affected (0.165 sec)

MariaDB [mytest]> EXPLAIN SELECT a FROM t1 GROUP BY a HAVING 1 != 1 AND a > 1;
-----------------------------------------------------------------+

id select_type table type possible_keys key key_len ref rows Extra

-----------------------------------------------------------------+

1 PUSHED SELECT NULL NULL NULL NULL NULL NULL NULL NULL

-----------------------------------------------------------------+
1 row in set (0.001 sec)

MariaDB [mytest]> EXPLAIN SELECT a FROM t1 GROUP BY a HAVING 1 != 1 AND a > 1;
-----------------------------------------------------------------+

id select_type table type possible_keys key key_len ref rows Extra

-----------------------------------------------------------------+

1 PUSHED SELECT NULL NULL NULL NULL NULL NULL NULL NULL

-----------------------------------------------------------------+
1 row in set (0.001 sec)

MariaDB [mytest]> EXPLAIN SELECT a FROM t1 GROUP BY a HAVING 1 != 1 AND a > 1;
-----------------------------------------------------------------+

id select_type table type possible_keys key key_len ref rows Extra

-----------------------------------------------------------------+

1 PUSHED SELECT NULL NULL NULL NULL NULL NULL NULL NULL

-----------------------------------------------------------------+
1 row in set (0.001 sec)

MariaDB [mytest]> EXPLAIN SELECT a FROM t1 GROUP BY a HAVING 1 != 1 AND a > 1;
-----------------------------------------------------------------+

id select_type table type possible_keys key key_len ref rows Extra

-----------------------------------------------------------------+

1 PUSHED SELECT NULL NULL NULL NULL NULL NULL NULL NULL

-----------------------------------------------------------------+
1 row in set (0.001 sec)

Generated at Thu Feb 08 02:45:16 UTC 2024 using Jira 8.20.16#820016-sha1:9d11dbea5f4be3d4cc21f03a88dd11d8c8687422.