partitions
Overview
Show the Partition status of all tables in the database.
Database
information_schema
Table Information
| Column Name | Type | Description |
|---|---|---|
| PARTITION_ID | bigint | Partitinon ID |
| TABLE_CATALOG | varchar(64) | Catalog name |
| TABLE_SCHEMA | varchar(64) | Database name |
| TABLE_NAME | varchar(64) | Table name |
| PARTITION_NAME | varchar(64) | Partition name |
| SUBPARTITION_NAME | varchar(64) | Always empty |
| PARTITION_ORDINAL_POSITION | int | Ordinal position of the partition |
| SUBPARTITION_ORDINAL_POSITION | int | Always empty |
| PARTITION_METHOD | varchar(13) | Partition method |
| SUBPARTITION_METHOD | varchar(13) | Always empty |
| PARTITION_EXPRESSION | varchar(2048) | Partition expression |
| SUBPARTITION_EXPRESSION | varchar(2048) | Always empty |
| PARTITION_DESCRIPTION | text | Partition description |
| TABLE_ROWS | bigint | |
| AVG_ROW_LENGTH | bigint | |
| DATA_LENGTH | bigint | |
| MAX_DATA_LENGTH | bigint | |
| INDEX_LENGTH | bigint | |
| DATA_FREE | bigint | |
| CREATE_TIME | bigint | |
| UPDATE_TIME | datetime | |
| CHECK_TIME | datetime | |
| CHECKSUM | bigint | |
| PARTITION_COMMENT | text | |
| NODEGROUP | varchar(256) | |
| TABLESPACE_NAME | varchar(268) | |
| LOCAL_DATA_SIZE | text | Partition local data size. Usually 0 in compute-storage decoupled mode, see below |
| REMOTE_DATA_SIZE | text | Partition remote data size (cloud) |
| STATE | text | Partition state |
| REPLICA_ALLOCATION | text | distribution of replicas of a tablet. NULL in compute-storage decoupled mode |
| REPLICA_NUM | int | replicas num |
| STORAGE_POLICY | text | Storage policy |
| STORAGE_MEDIUM | text | Storage medium |
| COOLDOWN_TIME_MS | text | Cooldown time |
| LAST_CONSISTENCY_CHECK_TIME | text | Last consistency check time |
| BUCKET_NUM | int | Partition bucket num |
| COMMITTED_VERSION | bigint | Last commited version |
| VISIBLE_VERSION | bigint | Current visible version |
| PARTITION_KEY | text | Partition key |
| RANGE | text | Partition range(min max value) |
| DISTRIBUTION | text | Distribution type |
Data size semantics in compute-storage decoupled mode
Starting from version 4.0.8, partition data size in compute-storage decoupled mode is consistently reported with remote semantics: data size that the replica statistics do not record as remote is counted into REMOTE_DATA_SIZE, and the corresponding LOCAL_DATA_SIZE is reported as 0. So in a decoupled cluster you usually see LOCAL_DATA_SIZE as 0, with the actual partition data size in REMOTE_DATA_SIZE.
Before 4.0.8, that data size was counted into LOCAL_DATA_SIZE, which made information_schema.partitions, SHOW TABLETS, and information_schema.backend_tablets contradict each other on local versus remote. The change only adjusts how the size is reported; it does not change where the data is stored or how much there is.
The same change makes REPLICA_ALLOCATION in information_schema.partitions display as NULL in decoupled mode (previously the internal placeholder \N). Replica placement is managed by the decoupled architecture itself and no longer follows the replica allocation semantics of the integrated mode.
When computing the actual space a partition occupies, use REMOTE_DATA_SIZE in decoupled mode:
SELECT
TABLE_SCHEMA,
TABLE_NAME,
PARTITION_NAME,
LOCAL_DATA_SIZE,
REMOTE_DATA_SIZE
FROM information_schema.partitions
WHERE TABLE_SCHEMA = 'your_db';
