Project: StarRocks (App Definition and Development / Database)
File: partitions.md

displayed_sidebar: "English" `partitions` provides information about table partitions. The following fields are provided in `partitions`: | Field | Description | | -- | | | TABLE_CATALOG | The name of the catalog to which the table belongs. This value is always `def`. | | TABLE_SCHEMA | The name of the database to which the table belongs. | | TABLE_NAME | The name of the table containing the partition. | | PARTITION_NAME | The name of the partition. | | SUBPARTITION_NAME | If the `PARTITIONS` table row represents a subpartition, the name of subpartition; otherwise `NULL`.For `NDB`: This value is always `NULL`. | | PARTITIONORDINALPOSITION | All partitions are indexed in the same order as they are defined, with `1` being the number assigned to the first partition. The indexing can change as partitions are added, dropped, and reorganized; the number shown is this column reflects the current order, taking into account any indexing changes. | | PARTITION_METHOD | Valid values: `RANGE`, `LIST`, `HASH`, `LINEAR HASH`, `KEY`, or `LINEAR KEY`. | | SUBPARTITION_METHOD | Valid values: `HASH`, `LINEAR HASH`, `KEY`, or `LINEAR KEY` | | PARTITION_EXPRESSION | The expression for the partitioning function used in the `CREATE TABLE` or `ALTER TABLE` statement that created the table's current partitioning scheme. | | SUBPARTITIONEXPRESSION | This works in the same fashion for the subpartitioning expression that defines the subpartitioning for a table as `PARTITIONEXPRESSION` does for the partitioning expression used to define a table's partitioning. If the table has no subpartitions, this column is `NULL`. | | PARTITIONDESCRIPTION | This column is used for RANGE and LIST partitions. For a `RANGE` partition, it contains the value set in the partition's `VALUES LESS THAN` clause, which can be either an integer or `MAXVALUE`. For a `LIST` partition, this column contains the values defined in the partition's `VALUES IN` clause, which is a list of comma-separated integer values.For partitions whose `PARTITIONMETHOD` is other than `RANGE` or `LIST`, this column is always `NULL`. | | TABLE_ROWS | The number of table rows in the partition. | | AVGROWLENGTH | The average length of the rows stored in this partition or subpartition, in bytes. This is the same as `DATALENGTH` divided by `TABLEROWS`. | | DATA_LENGTH | The total length of all rows stored in this partition or subpartition, in bytes; that is, the total number of bytes stored in the partition or subpartition. | | MAXDATALENGTH | The maximum number of bytes that can be stored in this partition or subpartition. | | INDEX_LENGTH | The length of the index file for this partition or subpartition, in bytes. | | DATA_FREE | The number of bytes allocated to the partition or subpartition but not used. | | CREATE_TIME | The time that the partition or subpartition was created. | | UPDATE_TIME | The time that the partition or subpartition was last modified. | | CHECK_TIME | The last time that the table to which this partition or subpartition belongs was checked. | | CHECKSUM | The checksum value, if any; otherwise `NULL`. | | PARTITION_COMMENT | The text of the comment, if the partition has one. If not, this value is empty. | | NODEGROUP | This is the nodegroup to which the partition belongs. | | TABLESPACE_NAME | The name of the tablespace to which the partition belongs. |