GreenPlum DBA常用SQL
GreenPlum DBA常用SQL 查看对象大小(表、索引、数据库等) select pg_size_pretty(pg_relation_size($schema.$table)); 查看用户(非系统)表和索引 select * from pg_stat_user_tables; seect * from pg_stat_user_indexes; www.2cto.com 查看表分区 select b.
GreenPlum DBA常用SQL
查看对象大小(表、索引、数据库等)
select pg_size_pretty(pg_relation_size(’$schema.$table’));
查看用户(非系统)表和索引
select * from pg_stat_user_tables;
seect * from pg_stat_user_indexes;
www.2cto.com
查看表分区
select b.nspname||’.'||a.relname as tablename, d.parname as partname
from pg_class a, pg_namespace b, pg_partition c, pg_partition_rule d
where a.relnamespace = b.oid
and b.nspname = ‘$schema’
and a.relname = ‘$table’
and a.oid = c.parrelid
and c.oid = d.paroid
order by parname;
查看Distributed key
select b.attname
from pg_class a, pg_attribute b, pg_type c, gp_distribution_policy d, pg_namespace e
where d.localoid = a.oid
and a.relnamespace = e.oid
and e.nspname = ‘$schema’
and a.relname=’$table’
and a.oid = b.attrelid
and b.atttypid = c.oid
and b.attnum > 0
and b.attnum = any(d.attrnums)
order by attnum;
www.2cto.com
查看当前存活的查询
select procpid as pid, sess_id as session, usename as user, current_query as query, waiting,
date_trunc(’second’, query_start) as start_time, client_addr as useraddr
from pg_stat_activity
where datname =’$PGDATABASE’
and current_query not like ‘%from pg_stat_activity%where datname =%’
order by start_time;
表上被用作外键的字段名
select f.conname, pg_get_constraintdef(f.oid), t2.relname
from pg_class t, pg_class t2, pg_constraint f
where f.confrelid = t.oid
and f.conrelid = t2.oid
and f.contype = ‘f’
and t.relname = ‘$table’;
www.2cto.com
1. 查看表使用空间
SELECT *
FROM PUBLIC.dba_segments
WHERE owner LIKE 'owber_name'
AND table_name LIKE '%table_name%'
ORDER BY table_name;
2. GP中查看分区:
select partitionname,partitionboundary from pg_partitions where tablename='table_name';
select partitionname,partitionboundary from pg_catalog.pg_partitions where tablename='table_name';
3. 查看正在运行的sql
select * from pg_stat_activity;
4. 修改表的owner语句
Alter table table_name owner to owner_name;
www.2cto.com
5. 增加表分区
ALTER TABLE table_name ADD PARTITION P20091001 START (DATE '2009-10-01') INCLUSIVE END (DATE '2009-10-02') EXCLUSIVE WITH(appendonly=true,compresslevel=5);
6. 修改列类型
ALTER TABLE table_name ALTER COLUMN a TYPE varchar(2048);
7. 修改distributed 列
alter table table_name set distributed by(column_1);

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

HQL and SQL are compared in the Hibernate framework: HQL (1. Object-oriented syntax, 2. Database-independent queries, 3. Type safety), while SQL directly operates the database (1. Database-independent standards, 2. Complex executable queries and data manipulation).

"Usage of Division Operation in OracleSQL" In OracleSQL, division operation is one of the common mathematical operations. During data query and processing, division operations can help us calculate the ratio between fields or derive the logical relationship between specific values. This article will introduce the usage of division operation in OracleSQL and provide specific code examples. 1. Two ways of division operations in OracleSQL In OracleSQL, division operations can be performed in two different ways.

What is Identity in SQL? Specific code examples are needed. In SQL, Identity is a special data type used to generate auto-incrementing numbers. It is often used to uniquely identify each row of data in a table. The Identity column is often used in conjunction with the primary key column to ensure that each record has a unique identifier. This article will detail how to use Identity and some practical code examples. The basic way to use Identity is to use Identit when creating a table.

Oracle and DB2 are two commonly used relational database management systems, each of which has its own unique SQL syntax and characteristics. This article will compare and differ between the SQL syntax of Oracle and DB2, and provide specific code examples. Database connection In Oracle, use the following statement to connect to the database: CONNECTusername/password@database. In DB2, the statement to connect to the database is as follows: CONNECTTOdataba

Interpretation of MyBatis dynamic SQL tags: Detailed explanation of Set tag usage MyBatis is an excellent persistence layer framework. It provides a wealth of dynamic SQL tags and can flexibly construct database operation statements. Among them, the Set tag is used to generate the SET clause in the UPDATE statement, which is very commonly used in update operations. This article will explain in detail the usage of the Set tag in MyBatis and demonstrate its functionality through specific code examples. What is Set tag Set tag is used in MyBati

Solution: 1. Check whether the logged-in user has sufficient permissions to access or operate the database, and ensure that the user has the correct permissions; 2. Check whether the account of the SQL Server service has permission to access the specified file or folder, and ensure that the account Have sufficient permissions to read and write the file or folder; 3. Check whether the specified database file has been opened or locked by other processes, try to close or release the file, and rerun the query; 4. Try as administrator Run Management Studio as etc.

How to use SQL statements for data aggregation and statistics in MySQL? Data aggregation and statistics are very important steps when performing data analysis and statistics. As a powerful relational database management system, MySQL provides a wealth of aggregation and statistical functions, which can easily perform data aggregation and statistical operations. This article will introduce the method of using SQL statements to perform data aggregation and statistics in MySQL, and provide specific code examples. 1. Use the COUNT function for counting. The COUNT function is the most commonly used

When Springboot+Mybatis-plus does not use SQL statements to perform multi-table adding operations, the problems I encountered are decomposed by simulating thinking in the test environment: Create a BrandDTO object with parameters to simulate passing parameters to the background. We all know that it is extremely difficult to perform multi-table operations in Mybatis-plus. If you do not use tools such as Mybatis-plus-join, you can only configure the corresponding Mapper.xml file and configure The smelly and long ResultMap, and then write the corresponding sql statement. Although this method seems cumbersome, it is highly flexible and allows us to
