I have a query like -
SELECT AdvElement.c_objectId , AdvElement.c_createdOn , AdvElement.c_modifiedOn ,
AdvElement.c_elementType , AdvElement.c_packageId , AdvElement.c_stereoTypeId ,
AdvElement.c_objectType , AdvElement.c_versionNumber , AdvModelElement.c_details ,
AdvModelElement.c_status , AdvModelElement.c_name , AdvModelElement.c_desc ,
AdvInstance.c_classifierId FROM AdvElement , AdvModelElement , AdvInstance , AdvObject
WHERE AdvElement.c_objectID = AdvModelElement.c_objectID and AdvModelElement.c_objectID
= AdvInstance.c_objectID and AdvInstance.c_objectID = AdvObject.c_objectID and
AdvElement.c_objectType = 'AdvObject'.
The query takes 1703.57 sec to execute.
The explain on the query gives
+----+-------------+-----------------+------+---------------+--------+---------+--------+------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref |
rows | Extra |
+----+-------------+-----------------+------+---------------+--------+---------+--------+------+-------------+
| 1 | SIMPLE | AdvInstance | ALL | [NULL] | [NULL] | [NULL] | [NULL] |
984 | |
| 1 | SIMPLE | AdvObject | ALL | [NULL] | [NULL] | [NULL] | [NULL] |
982 | Using where |
| 1 | SIMPLE | AdvElement | ALL | [NULL] | [NULL] | [NULL] | [NULL] |
1646 | Using where |
| 1 | SIMPLE | AdvModelElement | ALL | [NULL] | [NULL] | [NULL] | [NULL] |
1418 | Using where |
+----+-------------+-----------------+------+---------------+--------+---------+--------+------+-------------+
please suggest a solution to reduce the execution time.
