postgresql - pg_dump 压缩格式

Question

pg_dump compress 选项具有以下 description :

Specify the compression level to use. Zero means no compression. For the custom archive format, this specifies compression of individual table-data segments, and the default is to compress at a moderate level. For plain text output, setting a nonzero compression level causes the entire output file to be compressed, as though it had been fed through gzip; but the default is not to compress. The tar archive format currently does not support compression at all.

这是否意味着存档将采用 gzip 格式？

Answer 1

GZIP 文件格式有一个 header从字节 0x1f、0x8b 开始。

另一方面，pg_dump 自定义归档格式(选项 -Fc)生成的文件以字母 P、G、D、M、P 开头，足以断定它不是 gzip 格式。