# PROCEDURE ANALYSE

## Syntax

```sql
ANALYSE([max_elements[,max_memory]])
```

## Description

This procedure is defined in the `sql/sql_analyse.cc` file. It examines the result from a query and returns an analysis of the results that suggests optimal data types for each column. To obtain this analysis, append `PROCEDURE ANALYSE` to the end of a [SELECT](../../../sql-statements/data-manipulation/selecting-data/select) statement:

```sql
SELECT ... FROM ... WHERE ... PROCEDURE ANALYSE([max_elements,[max_memory]])
```

For example:

```sql
SELECT col1, col2 FROM table1 PROCEDURE ANALYSE(10, 2000);
```

The results show some statistics for the values returned by the query, and propose an optimal data type for the columns. This can be helpful for checking your existing tables, or after importing new data. You may need to try different settings for the arguments so that `PROCEDURE ANALYSE()` does not suggest the `ENUM` data type when it is not appropriate.

The arguments are optional and are used as follows:

* max\_elements (default 256) is the maximum number of distinct values that analyse notices per column. This is used by analyse to check whether the optimal data type should be of type `ENUM`; if there are more than max\_elements distinct values, then `ENUM` is not a suggested type.
* max\_memory (default 8192) is the maximum amount of memory that analyse should allocate per column while trying to find all distinct values.

## See Also

* [PROCEDURE](../../../sql-statements/data-manipulation/selecting-data/procedure)
* [SELECT](../../../sql-statements/data-manipulation/selecting-data/select)

<sub>_This page is licensed: GPLv2, originally from_</sub> [<sub>_fill\_help\_tables.sql_</sub>](https://github.com/MariaDB/server/blob/main/scripts/fill_help_tables.sql)

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