Information Schema PARTITIONS Table

The Information Schema PARTITIONS contains information about table partitions, with each record corresponding to a single partition or subpartition of a partitioned table. Each non-partitioned table also has a record in the PARTITIONS table, but most of the values are NULL.

It contains the following columns:

Column Description
TABLE_CATALOG Always def.
TABLE_SCHEMA Database name.
TABLE_NAME Table name containing the partition.
PARTITION_NAME Partition name.
SUBPARTITION_NAME Subpartition name, or NULL if not a subpartition.
PARTITION_ORDINAL_POSITION Order of the partition starting from 1.
SUBPARTITION_ORDINAL_POSITION Order of the subpartition starting from 1.
PARTITION_METHOD The partitioning type; one of RANGE, LIST, HASH, LINEAR HASH, KEY or LINEAR KEY.
SUBPARTITION_METHOD Subpartition type; one of HASH, LINEAR HASH, KEY or LINEAR KEY, or NULL if not a subpartition.
PARTITION_EXPRESSION Expression used to create the partition by the CREATE TABLE or ALTER TABLE statement.
SUBPARTITION_EXPRESSION Expression used to create the subpartition by the CREATE TABLE or ALTER TABLE statement, or NULL if not a subpartition.
PARTITION_DESCRIPTION For a RANGE partition, contains either MAXINTEGER or an integer, as set in the VALUES LESS THAN clause. For a LIST partition, contains a comma-separated list of integers, as set in the VALUES IN. NULL if another type of partition.
TABLE_ROWS Number of rows in the table (may be an estimate for some storage engines).
AVG_ROW_LENGTH Average row length, that is DATA_LENGTH divided by TABLE_ROWS
DATA_LENGTH Total number of bytes stored in all rows of the partition.
MAX_DATA_LENGTH Maximum bytes that could be stored in the partition.
INDEX_LENGTH Size in bytes of the partition index file.
DATA_FREE Unused bytes allocated to the partition.
CREATE_TIME Time the partition was created
UPDATE_TIME Time the partition was last modified.
CHECK_TIME Time the partition was last checked, or NULL for storage engines that don't record this information.
CHECKSUM Checksum value, or NULL if none.
PARTITION_COMMENT Partition comment, truncated to 80 characters, or an empty string if no comment.
NODEGROUP Node group, only used for MySQL Cluster, defaults to 0.
TABLESPACE_NAME Always default.
Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.

© 2021 MariaDB
Licensed under the Creative Commons Attribution 3.0 Unported License and the GNU Free Documentation License.
https://mariadb.com/kb/en/information-schema-partitions-table/