Re: [GENERAL] Need help - Regarding Data Compression in PostgreSQL.
On Tue, Dec 16, 2008 at 6:52 AM, salma salma.kha...@applabs.com wrote: Hi, I'd like to know: 1. If it is possible to compress data in the PostgreSQL. Ayup. Anything over a standard size gets compressed out of line into TOAST tables. 2. What kind of compression, if any, is available in PostgreSQL. Standard unix compress I believe 3. If compression is available, what kind of disk space savings can I expect using it. depends on how compressible your data is. The compression that's built into pgsql is focused on speed, not compression. So don't expect 99% compression or anything. But on highly compressible data you can expect it to compress quite well. Do an experiment with du and see what you get. A lot of this info is probably in the docs somewhere, but I'm not sure it's a faq or not. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] Need help - Regarding Data Compression in PostgreSQL.
Scott Marlowe escribió: On Tue, Dec 16, 2008 at 6:52 AM, salma salma.kha...@applabs.com wrote: 2. What kind of compression, if any, is available in PostgreSQL. Standard unix compress I believe No, it's our own LZ implementation, which is focused on speed but does not compress as well as gzip or compress (see src/backend/utils/adt/pg_lzcompress.c for more details) 3. If compression is available, what kind of disk space savings can I expect using it. depends on how compressible your data is. The compression that's built into pgsql is focused on speed, not compression. So don't expect 99% compression or anything. Well, you can compress 200 constant bytes to 4 with our algorithm, so it's 98% :-) (plus the varlena header though) -- Alvaro Herrerahttp://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] Need help - Regarding Data Compression in PostgreSQL.
I started feeling nobody wants to answer those questions but finally got a reply :-) Thanks a lot Scott. - Salma - Original Message - From: Scott Marlowe scott.marl...@gmail.com To: salma salma.kha...@applabs.com Cc: pgsql-nov...@postgresql.org; pgsql-general@postgresql.org Sent: Friday, December 19, 2008 5:36 AM Subject: Re: [GENERAL] Need help - Regarding Data Compression in PostgreSQL. On Tue, Dec 16, 2008 at 6:52 AM, salma salma.kha...@applabs.com wrote: Hi, I'd like to know: 1. If it is possible to compress data in the PostgreSQL. Ayup. Anything over a standard size gets compressed out of line into TOAST tables. 2. What kind of compression, if any, is available in PostgreSQL. Standard unix compress I believe 3. If compression is available, what kind of disk space savings can I expect using it. depends on how compressible your data is. The compression that's built into pgsql is focused on speed, not compression. So don't expect 99% compression or anything. But on highly compressible data you can expect it to compress quite well. Do an experiment with du and see what you get. A lot of this info is probably in the docs somewhere, but I'm not sure it's a faq or not. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
