介绍

PB级的装载能力（支持50PB）
遵从sql-92,SQL-99， SQL-2003，包括sql 2003 olAP扩展项
原生MapReduce功能

web GUI的greenplum数据仓库系统运行状态监控工具

有人提到，gp最大精华，就是分布式执行计划

Scatter/Gather 流引擎是专为并行数据加载和导出而设计，Scatter指数据通过并行加载服务器并行分散到各个数据节点，Gather指数据在 GPDB内部可以根据分布策略按需并行分发。

模式 scheR_693_11845@a

使用

连接

yum -y install POSTGResql
psql -d gp -h 1.2.3.4 -p 5432 -U gpadmin

操作

pqsql命令

Help可以打印出总的帮助信息
\?有点类似man，可以看到pqsql的命令帮助

数据库

创建：

createdb -h 192.168.123.92 -p 5432 -U gpadmin db_t

查看数据库列表

psql -l -h 192.168.123.92 -p 5432 -U gpadmin
[root@slb1 ~]# psql -l -h 192.168.123.92 -p 5432 -U gpadmin
 List of databases
 name | owner | EnCoding | Access privileges -----------+---------+----------+---------------------
 db_t | gpadmin | UTF8 | 

列出所有数据库

db_t=# \l
                  List of databases
   name    |  owner  | EnCoding |  Access privileges  
-----------+---------+----------+---------------------
 db_t      | gpadmin | UTF8     | 
 gp        | gpadmin | UTF8     | 
 POSTGRes  | gpadmin | UTF8     | 
 shajia    | gpadmin | UTF8     | 
 template0 | gpadmin | UTF8     | =c/gpadmin
                                : gpadmin=CTc/gpadmin
 template1 | gpadmin | UTF8     | =c/gpadmin
                                : gpadmin=CTc/gpadmin
(6 rows)

表

创建表

db_t=# CREATE table t1 ( i1 int PRI@R_772_11035@ KEY,i2 int,s1 varchar(40) );

如果给出了模式名（比如，create table myscheR_693_11845@a.myTable …）， 那么表是在指定模式中创建的。否则它在当前模式中创建。

create table t_scheR_693_11845@a.t3 ( i1 int PRI@R_772_11035@ KEY,s1 varchar(40) );

列出表的详细信息

db_t=# \d+ t3
                         table "t_scheR_693_11845@a.t3"
 column |         Type          | @H_405_83@modifIErs | Storage  | Description 
--------+-----------------------+-----------+----------+-------------
 i1     | Integer | not null | plain | 
 i2     | Integer |           | plain | 
 s1     | character varying(40) |           | extended | 
Indexes:
    "t3_pkey" PRI@R_772_11035@ KEY,btree (i1)
Has OIDs: no

列出当前模式scheR_693_11845@a下所有表

db_t=# \dt
        List of relations
 scheR_693_11845@a | name | Type  |  owner  
--------+------+-------+---------
 public | t1   | table | gpadmin
(1 row)

查看所有表，抛开模式scheR_693_11845@a

db_t=# SELEct schemaname,tablename,tableowner from pg_tables;
     schemaname     |           tablename           | tableowner 
--------------------+-------------------------------+------------
 information_scheR_693_11845@a | sql_languages                 | gpadmin
 information_scheR_693_11845@a | sql_packages                  | gpadmin
 ...                | ...                           | ...
 public             | t1                            | gpadmin
 public             | t2                            | gpadmin
 t_scheR_693_11845@a           | t3                            | gpadmin
(90 rows)

模式

列出模式

db_t=# \dn
       List of scheR_693_11845@as
        name        | owner 
--------------------+---------
 gp_toolkit         | gpadmin
 information_scheR_693_11845@a | gpadmin
 pg_aoseg           | gpadmin
 pg_bitmAPIndex     | gpadmin
 pg_catalog         | gpadmin
 pg_toast           | gpadmin
 public             | gpadmin
(7 rows)

创建新模式scheR_693_11845@a

CREATE scheR_693_11845@A t_scheR_693_11845@a;

删除模式scheR_693_11845@a

DROP scheR_693_11845@A t_scheR_693_11845@a;

查看当前模式

db_t=# SHOW search_path;
 search_path ----------------
 "$user",public
(1 row)

修改默认模式

db_t=# SET search_path=t_scheR_693_11845@a;
SET Time: 14.754 ms db_t=# SHOW search_path;
 search_path 
-------------
 t_scheR_693_11845@a
(1 row)

其他

#显示命令执行的时间
\timing

基础

深入

评测

参考

pgsql的命令