Mysql explain

EXPLAIN ANALYZE can be used with SELECT statements, as well as with multi-table UPDATE and DELETE statements. KILL QUERY or CTRL-C. The EXPLAIN keyword is used throughout various SQL databases and provides information about how your SQL database executes a query. The MYSQL explain query shows key NULL.

You can see information about the plan by prefixing the query with EXPLAIN. If you want to learn about technical terminology more easily, without frustrations, you’ve come to the right place. We make web hosting easy, but do our best to explain it in plain English too.

MySQL Explain output - Stack. Below shows the composition of the index and columns used. Going back to our simple query: it is a SIMPLE type of select with a const type of join. If I run thequery normally I get as expected. Adding the ` explain format=json` I get the json output.

EXTENDED keyword is unnecessary. This information can help optimize SQL performance. EXPLAIN returns a row of information for each table used in the SELECT statement.

I have a function that does a lot of work and I would like to analyze the performance of the function. Check whether the numbers are even close to the truth by comparing the rows product with the actual number of rows that the query returns. On Windows, the socket variable is the name of the named pipe that is used for local client connections. On Unix platforms, the socket variable is the name of the socket file that is used for local client connections. Rich graphs that drill down into detailed query information provide significantly better visibility into database performance issues.

The query optimizer uses the index cardinality to generate an optimal query plan for a given query. It also uses the index cardinality to decide whether to use the index or not in the join operations. Any Explainations for this behavior? Is it because expirydatetime is used within a mysql in-built function? Will mysql still consider the index on expirydatetime?

The DESCRIBE and EXPLAIN statements are synonyms. First of all, EXPLAIN shows the number of examined rows. EXPLAIN will show the number of rows in the table, not 0. The BETWEEN operator is a logical operator that allows you to specify whether a value in a range or not.

SQL is a standard language for storing, manipulating and retrieving data in databases. Each database has its characteristics and conditions. If you are developing an application which is going to be used by a huge audience on a regular basis then you need to make sure that your database and queries are optimized in order to provide stress-free user experience.

I have added the indexes however the sql query still slow and the type is ALL when EXPLAIN in the mysql. I have also include the EXPLAIN and TABLE schema and indexes. Anyone have any ideas or suggestions are much appreciated. REGID` AS `REGID`,`r`.

FK_question_id` INNER JOIN.