概述
Oracle_fdw 是一种postgresql外部表插件，可以读取到Oracle上面的数据。是一种非常方便且常见的pg与Oracle的同步数据的方法
配置Oracle环境
Oracle_fdw 的编译依赖系统中需要有pg_config和Oracle的环境，如果没有，就很难安装成功，需要安装一个。
安装Oracle客户端
- 从官网下载 instantclient-basic-linux.x64-12.2.0.1.0.zip、 instantclient-sdk-linux.x64-12.2.0.1.0.zip、 instantclient-sqlplus-linux.x64-12.2.0.1.0.zip三个文件包，并放到/opt/oracle/目录下
mv instantclient-basic-linux.x64-12.2.0.1.0.zip instantclient-sdk-linux.x64-12.2.0.1.0.zip instantclient-sqlplus-linux.x64-12.2.0.1.0.zip /opt/oracle/- 解压三个文件包
unzip instantclient-basic-linux.x64-12.2.0.1.0.zip
unzip instantclient-sdk-linux.x64-12.2.0.1.0.zip
unzip instantclient-sqlplus-linux.x64-12.2.0.1.0.zip- 解压后会生成instantclient_12_2 目录，将其更名为instantclient
mv instantclient_12_2 instantclient下载和编译安装
进入解压目录
[root@pg01 opt]# cd oracle_fdw-2.0.0/
[root@pg01 oracle_fdw-2.0.0]# ls
CHANGELOG LICENSE META.json oracle_fdw--1.1.sql oracle_fdw.control oracle_gis.c README.oracle_fdw TODO
expected Makefile oracle_fdw--1.0--1.1.sql oracle_fdw.c oracle_fdw.h oracle_utils.c sqlmake
[root@pg01 oracle_fdw-2.0.0]# make
gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -fPIC -I/sdk/include -I/oci/include -I/rdbms/public -I/usr/include/oracle/12.2/client -I/usr/include/oracle/12.2/client64 -I/usr/include/oracle/12.1/client -I/usr/include/oracle/12.1/client64 -I/usr/include/oracle/11.2/client -I/usr/include/oracle/11.2/client64 -I/usr/include/oracle/11.1/client -I/usr/include/oracle/11.1/client64 -I/usr/include/oracle/10.2.0.5/client -I/usr/include/oracle/10.2.0.5/client64 -I/usr/include/oracle/10.2.0.4/client -I/usr/include/oracle/10.2.0.4/client64 -I/usr/include/oracle/10.2.0.3/client -I/usr/include/oracle/10.2.0.3/client64 -I. -I./ -I/usr/pgsql-9.6/include/server -I/usr/pgsql-9.6/include/internal -D_GNU_SOURCE -I/usr/include/libxml2 -I/usr/include -c -o oracle_fdw.o oracle_fdw.c
gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -fPIC -I/sdk/include -I/oci/include -I/rdbms/public -I/usr/include/oracle/12.2/client -I/usr/include/oracle/12.2/client64 -I/usr/include/oracle/12.1/client -I/usr/include/oracle/12.1/client64 -I/usr/include/oracle/11.2/client -I/usr/include/oracle/11.2/client64 -I/usr/include/oracle/11.1/client -I/usr/include/oracle/11.1/client64 -I/usr/include/oracle/10.2.0.5/client -I/usr/include/oracle/10.2.0.5/client64 -I/usr/include/oracle/10.2.0.4/client -I/usr/include/oracle/10.2.0.4/client64 -I/usr/include/oracle/10.2.0.3/client -I/usr/include/oracle/10.2.0.3/client64 -I. -I./ -I/usr/pgsql-9.6/include/server -I/usr/pgsql-9.6/include/internal -D_GNU_SOURCE -I/usr/include/libxml2 -I/usr/include -c -o oracle_utils.o oracle_utils.c
gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -fPIC -I/sdk/include -I/oci/include -I/rdbms/public -I/usr/include/oracle/12.2/client -I/usr/include/oracle/12.2/client64 -I/usr/include/oracle/12.1/client -I/usr/include/oracle/12.1/client64 -I/usr/include/oracle/11.2/client -I/usr/include/oracle/11.2/client64 -I/usr/include/oracle/11.1/client -I/usr/include/oracle/11.1/client64 -I/usr/include/oracle/10.2.0.5/client -I/usr/include/oracle/10.2.0.5/client64 -I/usr/include/oracle/10.2.0.4/client -I/usr/include/oracle/10.2.0.4/client64 -I/usr/include/oracle/10.2.0.3/client -I/usr/include/oracle/10.2.0.3/client64 -I. -I./ -I/usr/pgsql-9.6/include/server -I/usr/pgsql-9.6/include/internal -D_GNU_SOURCE -I/usr/include/libxml2 -I/usr/include -c -o oracle_gis.o oracle_gis.c
gcc -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -fPIC -shared -o oracle_fdw.so oracle_fdw.o oracle_utils.o oracle_gis.o -L/usr/pgsql-9.6/lib -Wl,--as-needed -L/usr/lib64 -Wl,--as-needed -Wl,-rpath,'/usr/pgsql-9.6/lib',--enable-new-dtags -L -L/bin -L/lib -lclntsh -L/usr/lib/oracle/12.2/client/lib -L/usr/lib/oracle/12.2/client64/lib -L/usr/lib/oracle/12.1/client/lib -L/usr/lib/oracle/12.1/client64/lib -L/usr/lib/oracle/11.2/client/lib -L/usr/lib/oracle/11.2/client64/lib -L/usr/lib/oracle/11.1/client/lib -L/usr/lib/oracle/11.1/client64/lib -L/usr/lib/oracle/10.2.0.5/client/lib -L/usr/lib/oracle/10.2.0.5/client64/lib -L/usr/lib/oracle/10.2.0.4/client/lib -L/usr/lib/oracle/10.2.0.4/client64/lib -L/usr/lib/oracle/10.2.0.3/client/lib -L/usr/lib/oracle/10.2.0.3/client64/lib make install
[root@pg01 oracle_fdw-2.0.0]# make install
/usr/bin/mkdir -p '/usr/pgsql-9.6/lib'
/usr/bin/mkdir -p '/usr/pgsql-9.6/share/extension'
/usr/bin/mkdir -p '/usr/pgsql-9.6/share/extension'
/usr/bin/mkdir -p '/usr/pgsql-9.6/doc/extension'
/usr/bin/install -c -m 755 oracle_fdw.so '/usr/pgsql-9.6/lib/oracle_fdw.so'
/usr/bin/install -c -m 644 .//oracle_fdw.control '/usr/pgsql-9.6/share/extension/'
/usr/bin/install -c -m 644 .//oracle_fdw--1.1.sql .//oracle_fdw--1.0--1.1.sql '/usr/pgsql-9.6/share/extension/'
/usr/bin/install -c -m 644 .//README.oracle_fdw '/usr/pgsql-9.6/doc/extension/'使用
安装完成之后，看动态库中oracle_fdw.so y有没有成功生成
解决使用依赖
ldd 这个动态库文件，会显示缺少哪一些依赖。要把这些依赖都解决才能使用
我的解决方法
使用
创建拓展
create extention oracle_fdwCREATE SERVER server_pgsql_oracle_fdw FOREIGN DATA WRAPPER oracle_fdw OPTIONS (dbserver '//192.168.10.248:1521/orcl');
CREATE USER MAPPING FOR public SERVER server_pgsql_oracle_fdw OPTIONS (user 'kebyy2013', password 'kebyy2013');
