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What are EXPLAIN and EXPLAIN ANALYZE?
sobes.tech AI
Answer from AI
EXPLAIN and EXPLAIN ANALYZE are commands in SQL that help understand how the database engine executes a query.
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EXPLAIN shows the execution plan of a query, i.e., what operations will be performed (such as table scans, index usage, joins), but does not execute the query itself.
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EXPLAIN ANALYZE executes the query and additionally shows the actual time taken for each operation, the number of rows processed, and other statistics, which helps identify bottlenecks in performance.
In practice, this is used for query optimization: first, the plan is examined with EXPLAIN, then real costs are checked with EXPLAIN ANALYZE, and the query or indexes are adjusted accordingly.
Example:
EXPLAIN SELECT * FROM users WHERE age > 30;
EXPLAIN ANALYZE SELECT * FROM users WHERE age > 30;