SHOW TABLE STATUS
功能描述
查看当前库(或schema)的表状态。
注意事项
若不指定db_name,查询的是当前库(或schema)下的表状态。
语法格式
SHOW TABLE STATUS
[{FROM | IN} db_name]
[LIKE 'pattern' | WHERE expr]
参数说明
db_name
库名(或schema),可选项,若不指定,则查询的是当前库或schema。
LIKE ‘pattern’
pattern匹配显示结果第一列(列名为'Name [`pattern`]')。
输出字段说明
字段 | 含义 |
---|---|
Name | 表名 |
Engine | 存储引擎类型。取值范围:USTORE,表示表支持Inplace-Update存储引擎。ASTORE,表示表支持Append-Only存储引擎。 |
Version | 默认值NULL |
Row_format | 存储方式。取值范围:ROW,表示表的数据将以行式存储。COLUMN,表示表的数据将以列式存储。 |
Rows | 行数 |
Avg_row_length | 默认值NULL |
Data_length | 数据大小,由pg_relation_size(oid)获得 |
Max_data_length | 默认值NULL |
Index_length | 索引大小,由pg_indexes_size(oid)获得 |
Data_free | 默认值NULL |
Auto_increment | 当primary key为sequence时获取其last值 |
Create_time | 创建时间 |
Update_time | 更新时间 |
Check_time | 默认值NULL |
Collation | 排序集 |
Checksum | 默认值NULL |
Create_options | 建表选项 |
Comment | 注释 |
示例
opengauss=# CREATE SCHEMA tst_schema;
opengauss=#
opengauss=# SET SEARCH_PATH TO tst_schema;
opengauss=#
opengauss=# CREATE TABLE tst_t1
opengauss-# (
opengauss(# id serial primary key,
opengauss(# name varchar(20),
opengauss(# phone text
opengauss(# )WITH(ORIENTATION=ROW, STORAGE_TYPE=USTORE);
opengauss=#
opengauss=# COMMENT ON TABLE tst_t1 IS 'this is comment';
opengauss=#
opengauss=# CREATE VIEW tst_v1 AS SELECT * FROM tst_t1;
opengauss=#
opengauss=# CREATE TABLE tst_t2
opengauss-# (
opengauss(# id serial primary key,
opengauss(# name varchar(20),
opengauss(# phone text
opengauss(# )WITH(ORIENTATION=COLUMN);
opengauss=#
--查看表状态
opengauss=# show table status;
Name | Engine | Version | Row_format | Rows | Avg_row_length | Data_length | Max_data_length | Index_length | Data_free | Auto_increment | Create_time | Update_time | Check_time | Collation | Checksum | Create_options | Comment
--------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+---------------------+------------+-------------+----------+------------------------------------------------------+-----------------
tst_t1 | USTORE | | ROW | 0 | 0 | 0 | 0 | 57344 | 0 | 1 | 2022-10-18 09:04:24 | 2022-10-18 09:04:24 | | en_US.UTF-8 | | {orientation=row,storage_type=ustore,compression=no} | this is comment
tst_t2 | ASTORE | | COLUMN | 0 | 0 | 24576 | 0 | 8192 | 0 | 1 | 2022-10-18 09:04:24 | 2022-10-18 09:04:24 | | en_US.UTF-8 | | {orientation=column,compression=low} |
tst_v1 | | | | 0 | 0 | 0 | 0 | 0 | 0 | | 2022-10-18 09:04:24 | 2022-10-18 09:04:24 | | en_US.UTF-8 | | |
(3 rows)
--like 模糊匹配
opengauss=# show table status in tst_schema like '%tst_t%';
Name | Engine | Version | Row_format | Rows | Avg_row_length | Data_length | Max_data_length | Index_length | Data_free | Auto_increment | Create_time | Update_time | Check_time | Collation | Checksum | Create_options | Comment
--------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+---------------------+------------+-------------+----------+------------------------------------------------------+-----------------
tst_t1 | USTORE | | ROW | 0 | 0 | 0 | 0 | 57344 | 0 | 1 | 2022-10-18 09:04:24 | 2022-10-18 09:04:24 | | en_US.UTF-8 | | {orientation=row,storage_type=ustore,compression=no} | this is comment
tst_t2 | ASTORE | | COLUMN | 0 | 0 | 24576 | 0 | 8192 | 0 | 1 | 2022-10-18 09:04:24 | 2022-10-18 09:04:24 | | en_US.UTF-8 | | {orientation=column,compression=low} |
(2 rows)
--where 条件筛选
opengauss=# show table status from tst_schema where Engine='ASTORE';
Name | Engine | Version | Row_format | Rows | Avg_row_length | Data_length | Max_data_length | Index_length | Data_free | Auto_increment | Create_time | Update_time | Check_time | Collation | Checksum | Create_options | Comment
--------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+---------------------+------------+-------------+----------+--------------------------------------+---------
tst_t2 | ASTORE | | COLUMN | 0 | 0 | 24576 | 0 | 8192 | 0 | 1 | 2022-10-18 09:04:24 | 2022-10-18 09:04:24 | | en_US.UTF-8 | | {orientation=column,compression=low} |
(1 row)