磁盘空间不足的情况下，利用命名或者匿名管道迁移和导入数据；需要注意命名管道的权限问题。 0. name pip 0[pg@h1 ~]$ psql gtlions -ac select t3 tab,count(*) from t3 union all select t4,count(*) from t4;select t3 tab,count(*) from t3 union all se
磁盘空间不足的情况下，利用命名或者匿名管道迁移和导入数据；需要注意命名管道的权限问题。
0. name pip 0[pg@h1 ~]$ psql gtlions -ac select 't3' tab,count(*) from t3 union all select 't4',count(*) from t4;select 't3' tab,count(*) from t3 union all select 't4',count(*) from t4; tab | count-----+------- t3 | 100 t4 | 0(2 rows) [pg@h1 ~]$ mknod syncpip p[pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to '/home/pg/sync'|psql gtlions -p 5432 -c copy t4 from '/home/pg/sync' error: could not open file /home/pg/sync for reading: no such file or directory[pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to '/home/pg/syncpip'|psql gtlions -p 5432 -c copy t4 from '/home/pg/syncpip' copy 100[pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to '/home/pg/syncpip'|psql gtlions -p 5432 -c copy t4 from '/home/pg/syncpip' copy 100[pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to '/home/pg/syncpip'|psql gtlions -p 5432 -c copy t4 from '/home/pg/syncpip' copy 100[pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to '/home/pg/syncpip'|psql gtlions -p 5432 -c copy t4 from '/home/pg/syncpip' copy 100[pg@h1 ~]$ psql gtlions -ac select 't3' tab,count(*) from t3 union all select 't4',count(*) from t4;select 't3' tab,count(*) from t3 union all select 't4',count(*) from t4; tab | count-----+------- t3 | 100 t4 | 400(2 rows)1. name pip 1[pg@h1 ~]$ rm -rf sync*[pg@h1 ~]$ mkfifo syncpip[pg@h1 ~]$ ll syncpipprw-rw-r-- 1 pg pg 0 11月 6 09:15 syncpip[pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to '/home/pg/syncpip'|psql gtlions -p 5432 -c copy t4 from '/home/pg/syncpip' copy 100[pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to '/home/pg/syncpip'|psql gtlions -p 5432 -c copy t4 from '/home/pg/syncpip' copy 100[pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to '/home/pg/syncpip'|psql gtlions -p 5432 -c copy t4 from '/home/pg/syncpip' copy 100[pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to '/home/pg/syncpip'|psql gtlions -p 5432 -c copy t4 from '/home/pg/syncpip' copy 100[pg@h1 ~]$ psql gtlions -ac select 't3' tab,count(*) from t3 union all select 't4',count(*) from t4;select 't3' tab,count(*) from t3 union all select 't4',count(*) from t4; tab | count-----+------- t3 | 100 t4 | 800(2 rows) 2. unname pip[pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to stdout|psql gtlions -p 5432 -c copy t4 from stdin [pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to stdout|psql gtlions -p 5432 -c copy t4 from stdin [pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to stdout|psql gtlions -p 5432 -c copy t4 from stdin [pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to stdout|psql gtlions -p 5432 -c copy t4 from stdin [pg@h1 ~]$ psql gtlions -p 5432 -c copy t3 to '/home/pg/syncpip'|psql gtlions -p 5432 -c copy t4 from '/home/pg/syncpip' copy 100[pg@h1 ~]$ psql gtlions -ac select 't3' tab,count(*) from t3 union all select 't4',count(*) from t4; select 't3' tab,count(*) from t3 union all select 't4',count(*) from t4; tab | count-----+------- t3 | 100 t4 | 1300(2 rows)
-eof-