I need to store large amounts of text in Postgres, mainly command logs and the output of long running commands and need to know if there are some settings that could help compress the data transparently with a tool like zlib, or some other native space saving methods.
The data is primarily read only data, so writing is not a problem.
Best Answer
By default Postgres automatically compresses everything TEXT. It uses a simple lzcompress algorythm:
https://www.postgresql.org/docs/9.3/storage-toast.html
There is a plugin that will probably evolve to LZ4 compression support for TEXT:
https://github.com/zilder/pg_lz4
There is a FDW that also support compression:
https://www.citusdata.com/blog/2014/04/03/columnar-store-for-analytics/