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. For a SYSTEM_TIME INTERVAL partition, shows a defined upper boundary timestamp for historical values (the last history partition can contain values above the upper boundary). 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.
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