mysql.column_stats table is one of three tables storing data used for Engine-independent table statistics added in MariaDB 10.0.1. The others are mysql.table_stats and mysql.index_stats.The histogram fields were added in MariaDB 10.0.2 as part of the Histogram-based Statistics feature.
Note that statistics for blob and text columns are not collected. If explicitly specified, a warning is returned.
mysql.column_stats table contains the following fields:
|NO||PRI||Database the table is in.|
|NO||PRI||Name of the column.|
|YES||Minimum value in the table (in text form).|
|YES||Maximum value in the table (in text form).|
|YES||Fraction of |
|YES||Average length of column value, in bytes. Counted as if one ran |
|YES||Average number of records with the same value|
|YES||Histogram size in bytes, from 0-255, or, from MariaDB 10.7, number of buckets if the histogram type is |
|YES||Histogram type. See the histogram_type system variable.|
It is possible to manually update the table. See Manual updates to statistics tables for details.