Question :
In PostgreSQL, EXPLAIN or EXPLAIN ANALYZE will show the estimate cost of executing a query. But EXPLAIN in MySQL doesn’t provide this information. How can I get the estimate cost without installation of other tools? I’m using MySQL-5.6.16.
Answer :
There isn’t much out there for MySQL except the following:
- EXPLAIN EXTENDED followed by SHOW WARNINGS
- SHOW PROFILES (Older Releases of MySQL)
- MySQL PERFORMANCE_SCHEMA
Read these carefully, see what you think …
In short
- Run your
SELECT ...
query SHOW STATUS LIKE 'last_query_cost'
- if the answer was 0 rerun the query with
select SQL_NO_CACHE ...
and do step 2 above again