[pgtest@host ~]$ pg_dump -h 127.0.0.1 -E UTF8 -Fc francs -v > francs.dmp pg_dump: reading schemas pg_dump: reading user-defined tables pg_dump: reading extensions pg_dump: reading user-defined functions pg_dump: reading user-defined types pg_dump: reading procedural languages pg_dump: reading user-defined aggregate functions pg_dump: reading user-defined operators pg_dump: reading user-defined operator classes pg_dump: reading user-defined operator families pg_dump: reading user-defined text search parsers pg_dump: reading user-defined text search templates pg_dump: reading user-defined text search dictionaries pg_dump: reading user-defined text search configurations pg_dump: reading user-defined foreign-data wrappers pg_dump: reading user-defined foreign servers pg_dump: reading default privileges pg_dump: reading user-defined collations pg_dump: reading user-defined conversions pg_dump: reading type casts pg_dump: reading table inheritance information pg_dump: reading rewrite rules pg_dump: finding extension members pg_dump: finding inheritance relationships pg_dump: reading column info for interesting tables pg_dump: finding the columns and types of table "test_1" pg_dump: flagging inherited columns in subtables pg_dump: reading indexes pg_dump: reading constraints pg_dump: reading triggers pg_dump: reading large objects pg_dump: reading dependency data pg_dump: saving encoding = UTF8 pg_dump: saving standard_conforming_strings = on pg_dump: saving database definition pg_dump: [archiver] WARNING: requested compression not available in this installation -- archive will be uncompressed pg_dump: dumping contents of table test_1
备注:查看日志输出倒数第二行,”pg_dump: [archiver] WARNING: requested compression not available in this installation “ , 表示不支持压缩,而这个功能是备份数据库时压缩比高,非常有用。
总结
Readline 和 zlib 属性非常重要,在编译 PostgreSQL 时,强烈推荐启用。
附: Readline 和 Zlib
4.1 Readline 解释
The GNU Readline library is used by default. It allows psql (the PostgreSQL command line SQL interpreter) to remember each command you type, and allows you to use arrow keys to recall and edit previous commands. This is very helpful and is strongly recommended. If you do not want to use it then you must specify the –without-readline option to configure. As an alternative, you can often use the BSD-licensed libedit library, originally developed on NetBSD. The libedit library is GNU Readline-compatible and is used if libreadline is not found, or if –with-libedit-preferred is used as an option to configure. If you are using a package-based Linux distribution, be aware that you need both the readline and readline-devel packages, if those are separate in your distribution.
4.2 zlib 解释
The zlib compression library is used by default. If you do not want to use it then you must specify the –without-zlib option to configure. Using this option disables support for compressed archives in pg_dump and pg_restore.