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 [[email protected] ~]$ 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) [[email protected] ~]$ mknod syncpip p [[email protected] ~]$ 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 [[email protected] ~]$ psql gtlions -p 5432 -c "copy t3 to '/home/pg/syncpip'"|psql gtlions -p 5432 -c "copy t4 from '/home/pg/syncpip'" COPY 100 [[email protected] ~]$ psql gtlions -p 5432 -c "copy t3 to '/home/pg/syncpip'"|psql gtlions -p 5432 -c "copy t4 from '/home/pg/syncpip'" COPY 100 [[email protected] ~]$ psql gtlions -p 5432 -c "copy t3 to '/home/pg/syncpip'"|psql gtlions -p 5432 -c "copy t4 from '/home/pg/syncpip'" COPY 100 [[email protected] ~]$ psql gtlions -p 5432 -c "copy t3 to '/home/pg/syncpip'"|psql gtlions -p 5432 -c "copy t4 from '/home/pg/syncpip'" COPY 100 [[email protected] ~]$ 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 [[email protected] ~]$ rm -rf sync* [[email protected] ~]$ mkfifo syncpip [[email protected] ~]$ ll syncpip prw-rw-r-- 1 pg pg 0 11月 6 09:15 syncpip [[email protected] ~]$ psql gtlions -p 5432 -c "copy t3 to '/home/pg/syncpip'"|psql gtlions -p 5432 -c "copy t4 from '/home/pg/syncpip'" COPY 100 [[email protected] ~]$ psql gtlions -p 5432 -c "copy t3 to '/home/pg/syncpip'"|psql gtlions -p 5432 -c "copy t4 from '/home/pg/syncpip'" COPY 100 [[email protected] ~]$ psql gtlions -p 5432 -c "copy t3 to '/home/pg/syncpip'"|psql gtlions -p 5432 -c "copy t4 from '/home/pg/syncpip'" COPY 100 [[email protected] ~]$ psql gtlions -p 5432 -c "copy t3 to '/home/pg/syncpip'"|psql gtlions -p 5432 -c "copy t4 from '/home/pg/syncpip'" COPY 100 [[email protected] ~]$ 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 [[email protected] ~]$ psql gtlions -p 5432 -c "copy t3 to stdout"|psql gtlions -p 5432 -c "copy t4 from stdin" [[email protected] ~]$ psql gtlions -p 5432 -c "copy t3 to stdout"|psql gtlions -p 5432 -c "copy t4 from stdin" [[email protected] ~]$ psql gtlions -p 5432 -c "copy t3 to stdout"|psql gtlions -p 5432 -c "copy t4 from stdin" [[email protected] ~]$ psql gtlions -p 5432 -c "copy t3 to stdout"|psql gtlions -p 5432 -c "copy t4 from stdin" [[email protected] ~]$ psql gtlions -p 5432 -c "copy t3 to '/home/pg/syncpip'"|psql gtlions -p 5432 -c "copy t4 from '/home/pg/syncpip'" COPY 100 [[email protected] ~]$ 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)
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时间： 2024-07-28 19:36:29