Greenplum+Hadoop学习笔记-14-定义数据库对象之创建与管理数据库，hadoop-14-

testdw-# \h create database

Command:     CREATE DATABASE

Description: create a new database

Syntax:

CREATE DATABASE name

    [ [ WITH ] [ OWNER [=] dbowner ]

           [ TEMPLATE [=] template ]

           [ ENCODING [=] encoding ]

           [ LC_COLLATE [=] lc_collate ]

           [ LC_CTYPE [=] lc_ctype ]

           [ TABLESPACE [=] tablespace ]

           [ CONNECTION LIMIT [=] connlimit ] ]                 连接限制

template1=# create database devdw;

CREATE DATABASE

template1=#\c devdw                                     使用\c连接数据库                                    

You are now connected to database "devdw" as user "gpadmin".

devdw=# create table tab_01(id int);                          创建表

NOTICE:  Table doesn't have 'DISTRIBUTED BY' clause -- Using column named 'id' as the Greenplum Database data distribution key for this table.

HINT:  The 'DISTRIBUTED BY' clause determines the distribution of data. Make sure column(s) chosen are the optimal data distribution key to minimize skew.

CREATE TABLE

devdw=# \d                                              使用\d查看表信息

              List of relations

 Schema |  Name  | Type  |  Owner  | Storage

--------+--------+-------+---------+---------

 public | tab_01 | table | gpadmin | heap

(1 row)

devdw=# insert into tab_01 values(101);                      向表中插入数据

INSERT 0 1

devdw=# select * from tab_01;                             查询表中信息

 id 

-----

 101

(1 row)

template1=# create database col_devdw template devdw;           使用devdw作为模板创建克隆数据库

CREATE DATABASE

template1=# \l                                            使用\l命令查看当前所有数据库

                  List of databases

   Name    |  Owner  | Encoding |  Access privileges 

-----------+---------+----------+---------------------

 col_devdw | gpadmin | UTF8     |

 devdw     | gpadmin | UTF8     |

 postgres  | gpadmin | UTF8     |

 template0 | gpadmin | UTF8     | =c/gpadmin         

                                : gpadmin=CTc/gpadmin

 template1 | gpadmin | UTF8     | =c/gpadmin         

                                : gpadmin=CTc/gpadmin

 testdw    | gpadmin | UTF8     |

(6 rows)

template1=# \c col_devdw

You are now connected to database "col_devdw" as user "gpadmin".

col_devdw=# \l

                  List of databases

   Name    |  Owner  | Encoding |  Access privileges 

-----------+---------+----------+---------------------

 col_devdw | gpadmin | UTF8     |

 devdw     | gpadmin | UTF8     |

 postgres  | gpadmin | UTF8     |

 template0 | gpadmin | UTF8     | =c/gpadmin         

                                : gpadmin=CTc/gpadmin

 template1 | gpadmin | UTF8     | =c/gpadmin         

                                : gpadmin=CTc/gpadmin

 testdw    | gpadmin | UTF8     |

(6 rows)

col_devdw=# \d

              List of relations

 Schema |  Name  | Type  |  Owner  | Storage

--------&#