--- name: "\U0001F947 Ask a Database Performance Question" about: I want to ask a database performance question. labels: type/question, type/performance --- ## Performance Questions - What version of TiDB are you using? - What's the observed and your expected performance respectively? - Have you compared TiDB with other databases? If yes, what's their difference? - For a specific slow SQL query, please provide the following information: - Whether you analyzed the tables involved in the query and how long it is after you ran the last `ANALYZE`. - Whether this SQL query always or occasionally runs slowly. - The `EXPLAIN ANALYZE` result of this query if your TiDB version is higher than 2.1, or you can just provide the `EXPLAIN` result. - The plain text of the SQL query and table schema so we can test it locally. It would be better if you can provide the dumped statistics information. - The `EXPLAIN` result of the compared database. For MySQL, `EXPLAIN format=json`'s result will be more helpful. - Other information that is useful from your perspective. - For a general performance question, e.g. the benchmark result you got by yourself is not expected, please provide the following information: - Your cluster's topology architecture. - A simple description of you workload. - The metrics PDF generated from Grafana monitor. Remember to set the time range to the performance issue duration.