Improving the Performance of SQL Queries
Use this topic to find advice on improving the performance of slow queries.
Displaying the Execution Plan
Add the keyword
EXPLAIN in front of your query. For example:
EXPLAIN SELECT * FROM employees WHERE age > ?;
Scanning an entire table (full table scans) is the slowest way to access data, if you are filtering just a small subset of rows. If your queries are performing full table scans on a map, you can create indexes that contain at least one of the columns that the query is filtering in its
WHERE clause. See CREATE INDEX.