# PARTITIONS > PARTITIONS 表提供关于分区表的信息。 # PARTITIONS `PARTITIONS` 表提供了关于分区表的信息。 ```sql USE INFORMATION_SCHEMA; DESC PARTITIONS; ``` 结果如下： ```sql +-------------------------------+----------+------+------+---------+---------------+ | Column | Type | Key | Null | Default | Semantic Type | +-------------------------------+----------+------+------+---------+---------------+ | table_catalog | String | | NO | | FIELD | | table_schema | String | | NO | | FIELD | | table_name | String | | NO | | FIELD | | partition_name | String | | NO | | FIELD | | subpartition_name | String | | YES | | FIELD | | partition_ordinal_position | Int64 | | YES | | FIELD | | subpartition_ordinal_position | Int64 | | YES | | FIELD | | partition_method | String | | YES | | FIELD | | subpartition_method | String | | YES | | FIELD | | partition_expression | String | | YES | | FIELD | | subpartition_expression | String | | YES | | FIELD | | partition_description | String | | YES | | FIELD | | table_rows | Int64 | | YES | | FIELD | | avg_row_length | Int64 | | YES | | FIELD | | data_length | Int64 | | YES | | FIELD | | max_data_length | Int64 | | YES | | FIELD | | index_length | Int64 | | YES | | FIELD | | data_free | Int64 | | YES | | FIELD | | create_time | TimestampSecond | | YES | | FIELD | | update_time | TimestampSecond | | YES | | FIELD | | check_time | TimestampSecond | | YES | | FIELD | | checksum | Int64 | | YES | | FIELD | | partition_comment | String | | YES | | FIELD | | nodegroup | String | | YES | | FIELD | | tablespace_name | String | | YES | | FIELD | | greptime_partition_id | UInt64 | | YES | | FIELD | +-------------------------------+----------+------+------+---------+---------------+ 26 rows in set (0.01 sec) ``` 主要列包括： * `table_catalog`：表所属目录的名称。该值始终为 `def`。 * `table_schema`：表所属的 schema（数据库）的名称。 * `table_name`：包含分区（region）的表的名称。 * `partition_name`：分区（region）的名称。 * `partition_ordinal_position`：所有分区按照定义的顺序进行索引，1 是分配给第一个分区的编号。 * `partition_method`：该值始终为 `RANGE`，GreptimeDB 仅支持范围分区。 * `partition_expression`：该分区的表达式。 * `create_time`：分区创建的时间。 * `greptime_partition_id`：GreptimeDB 扩展字段，也就是 Region Id。 创建一张分区表并查询： ```sql CREATE TABLE public.test_p ( a INT PRIMARY KEY, b STRING, ts TIMESTAMP TIME INDEX, ) PARTITION ON COLUMNS (a) ( a < 10, a >= 10 AND a < 20, a >= 20 ); -- 查询表的分区信息 SELECT * FROM PARTITIONS WHERE table_schema='public' AND table_name='test_p'\G ``` 示例输出如下： ```sql *************************** 1. row *************************** table_catalog: greptime table_schema: public table_name: test_p partition_name: p0 subpartition_name: NULL partition_ordinal_position: 1 subpartition_ordinal_position: NULL partition_method: RANGE subpartition_method: NULL partition_expression: (a) VALUES LESS THAN (PartitionExpr { lhs: Column("a"), op: Lt, rhs: Value(Int32(10)) }) subpartition_expression: NULL partition_description: NULL table_rows: NULL avg_row_length: NULL data_length: NULL max_data_length: NULL index_length: NULL data_free: NULL create_time: 2024-04-01 10:49:49.468000 update_time: NULL check_time: NULL checksum: NULL partition_comment: NULL nodegroup: NULL tablespace_name: NULL greptime_partition_id: 4453881085952 *************************** 2. row *************************** table_catalog: greptime table_schema: public table_name: test_p partition_name: p1 subpartition_name: NULL partition_ordinal_position: 2 subpartition_ordinal_position: NULL partition_method: RANGE subpartition_method: NULL partition_expression: (a) VALUES LESS THAN (PartitionExpr { lhs: Column("a"), op: GtEq, rhs: Value(Int32(20)) }) subpartition_expression: NULL partition_description: NULL table_rows: NULL avg_row_length: NULL data_length: NULL max_data_length: NULL index_length: NULL data_free: NULL create_time: 2024-04-01 10:49:49.468000 update_time: NULL check_time: NULL checksum: NULL partition_comment: NULL nodegroup: NULL tablespace_name: NULL greptime_partition_id: 4453881085954 *************************** 3. row *************************** table_catalog: greptime table_schema: public table_name: test_p partition_name: p2 subpartition_name: NULL partition_ordinal_position: 3 subpartition_ordinal_position: NULL partition_method: RANGE subpartition_method: NULL partition_expression: (a) VALUES LESS THAN (PartitionExpr { lhs: Expr(PartitionExpr { lhs: Column("a"), op: Gt, rhs: Value(Int32(10)) }), op: And, rhs: Expr(PartitionExpr { lhs: Column("a"), op: Lt, rhs: Value(Int32(20)) }) }) subpartition_expression: NULL partition_description: NULL table_rows: NULL avg_row_length: NULL data_length: NULL max_data_length: NULL index_length: NULL data_free: NULL create_time: 2024-04-01 10:49:49.468000 update_time: NULL check_time: NULL checksum: NULL partition_comment: NULL nodegroup: NULL tablespace_name: NULL greptime_partition_id: 4453881085953 ```