postgresql兼容oracle插件orafce

orafce插件是postgresql兼容oracle的插件，安装了以后，pg能够兼容oracle的一些数据类型和表。

下载地址：https://pgxn.org/dist/orafce

环境：centos7.4

数据库：pg12.3

orafce：3.13

安装
[postgres@node1 ~]$ unzip orafce-3.13.4.zip 
[postgres@node1 ~]$ cd orafce-3.13.4/
[postgres@node1 orafce-3.13.4]$ make
[postgres@node1 orafce-3.13.4]$ make install
[postgres@node1 orafce-3.13.4]$ psql
psql (12.3)
Type "help" for help.

postgres=# create extension orafce ;
CREATE EXTENSION
postgres=# \dx
postgres=# \dx
                                                       List of installed extensions
        Name        | Version |   Schema   |                                          Description                                          
--------------------+---------+------------+-----------------------------------------------------------------------------------------------
 orafce             | 3.13    | public     | Functions and operators that emulate a subset of functions and packages from the Oracle RDBMS
 pg_stat_statements | 1.7     | public     | track execution statistics of all SQL statements executed
 plpgsql            | 1.0     | pg_catalog | PL/pgSQL procedural language
(3 rows)

使用oracle兼容的函数和表

postgres=# select * from dual ;
 dummy 
-------
 X
(1 row)

postgres=# SELECT CURRENT_DATE "date" FROM DUAL;
    date    
------------
 2021-08-02
(1 row)
postgres=# \dn
     List of schemas
     Name     |  Owner   
--------------+----------
 dbms_alert   | postgres
 dbms_assert  | postgres
 dbms_output  | postgres
 dbms_pipe    | postgres
 dbms_random  | postgres
 dbms_utility | postgres
 oracle       | postgres
 plunit       | postgres
 plvchr       | postgres
 plvdate      | postgres
 plvlex       | postgres
 plvstr       | postgres
 plvsubst     | postgres
 public       | postgres
 utl_file     | postgres
(15 rows)

postgres=# select * from oracle.user_tables;
       table_name        
-------------------------
 t1
 t2
 t3
 t4
 t11
 t12
 t13
 a1
 tbschedulejob
 utl_file_dir
 pg_statistic
 pg_type
 t5
 a2
 a11
 a22
 a23
 pg_foreign_server
 pg_authid
 pg_statistic_ext_data
 pg_user_mapping
 pg_subscription
 pg_attribute
 pg_proc
 pg_class
 pg_attrdef
 pg_constraint
 pg_inherits
 pg_index
 pg_operator
 pg_opfamily
 pg_opclass
 pg_am
 pg_amop
 pg_amproc
 pg_language
 pg_largeobject_metadata
 pg_aggregate
 pg_largeobject

支持特性

数据类型: varchar2、nvarchar2、 date
系统表：
dual 、user_tab_columns、user_tables、user_cons_columns、user_constraints、 product_component_version 、 user_objects 、user_procedures 、
user_source 、  user_views、user_ind_columns等

函数：

nvl、nvl2、lnvl、decode、bitand、nanvl、sinh、cosh等