Postgresql 远程同步(非实时同步，小数据量)
源端要开通目标的相关访问权限
目标端：
1.建立远程表的视图
create view v_bill_tbl_version_update_control_info as SELECT * FROM dblink('hostaddr=10.10.10.8 port=4321 dbname=postgres user=postgres password=postgres', 'SELECT id,appid,ratio,status,create_time,char_package_name,version from tbl_version_update_control_info') AS t(id integer,appid character(20),ratio integer,status character(1),create_time timestamp without time zone,char_package_name character varying(50),version character varying(8));
2.建立和远程表一样的判断表以及实体表
CREATE TABLE tbl_version_update_control_info (
id integer NOT NULL,
appid character(20) NOT NULL,
ratio integer DEFAULT 0 NOT NULL,
status character(1) DEFAULT 0 NOT NULL,
create_time timestamp without time zone DEFAULT now(),
char_package_name character varying(50),
version character varying(8)
);
CREATE TABLE work_table_tbl_version_update_control_info (
id integer NOT NULL,
appid character(20) NOT NULL,
ratio integer DEFAULT 0 NOT NULL,
status character(1) DEFAULT 0 NOT NULL,
create_time timestamp without time zone DEFAULT now(),
char_package_name character varying(50),
version character varying(8)
);
3.建立同步函数
CREATE OR REPLACE FUNCTION sync_tbl_version_update_control_info()
RETURNS integer
LANGUAGE plpgsql
AS $function$
declare
v_src_count int; --存放源数据统计数据
v_dst_count int; --存放目标端数据统计数据
v_equal_count int; --源端和目标端相同的数据
v_run int8; --统计运行改函数的进行数，如果大于1，说明存在，改函数在运行
begin
v_src_count := 0;
v_dst_count := 0;
v_equal_count := 0;
select count(*) into v_run from pg_stat_activity where query ~ 'sync_tbl_version_update_control_info';
if v_run>1 then
raise notice 'another process is running, this will exit soon.';
return 1;
end if;
if (pg_is_in_recovery()) then
raise notice 'pg_is_in_recovery is true.';
return 1;
end if;
truncate table ONLY work_table_tbl_version_update_control_info;
insert into work_table_tbl_version_update_control_info
(id,appid,ratio,status,create_time,char_package_name,version)
select id,appid,ratio,status,create_time,char_package_name,version from v_bill_tbl_version_update_control_info;
select count(*) into v_src_count from work_table_tbl_version_update_control_info;
select count(*) into v_dst_count from tbl_version_update_control_info;
raise notice 'v_src_count:%, v_dst_count:%',v_src_count,v_dst_count;
if ( v_src_count = v_dst_count and v_src_count <> 0 ) then
select count(*) into v_equal_count from work_table_tbl_version_update_control_info t1,tbl_version_update_control_info t2
where t1.id=t2.id
and t1.appid = t2.appid
and t1.ratio = t2.ratio
and t1.status = t2.status
and t1.create_time = t2.create_time
and t1.char_package_name = t2.char_package_name
and t1.version = t2.version;
raise notice 'v_src_count:%, v_dst_count:%, v_equal_count:%',v_src_count,v_dst_count,v_equal_coun
t;
if ( v_equal_count <> v_src_count ) then
truncate table ONLY tbl_version_update_control_info;
insert into tbl_version_update_control_info
(id,appid,ratio,status,create_time,char_package_name,version)
select id,appid,ratio,status,create_time,char_package_name,version from work_table_tbl_version_update_control_info;
end if;
elsif ( v_src_count <> v_dst_count and v_src_count <> 0 ) then
truncate table ONLY tbl_version_update_control_info;
insert into tbl_version_update_control_info
(id,appid,ratio,status,create_time,char_package_name,version)
select id,appid,ratio,status,create_time,char_package_name,version from work_table_tbl_version_update_control_info;
elsif v_src_count = 0 then
raise notice 'ERROR: src no data.';
return 1;
end if;
return 0;
end;
$function$
4.执行函数进行同步并确认同步
select sync_tbl_version_update_control_info();
select count(*) from tbl_version_update_control_info;
5.系统定时任务添加：
15 2 * * * /home/postgres/sync_data.sh >>/tmp/sync.log 2>&1
cat /home/postgres/sync_data.sh
echo -e "start sync tbl_version_update_control_info;"
date +%F\ %T
psql -h 127.0.0.1 hank hank -c "select * from sync_tbl_version_update_control_info()";
date +%F\ %T
echo -e "end sync tbl_version_update_control_info;"