On Fri, Dec 17, 2010 at 12:08 PM, Tom Polak <tom@xxxxxxxxxxxxxxxxxxxxxxxx> wrote: > What kind of performance can I expect out of Postgres compare to MSSQL? > Let's assume that Postgres is running on Cent OS x64 and MSSQL is running > on Windows 2008 x64, both are on identical hardware running RAID 5 (for > data redundancy/security), SAS drives 15k RPM, dual XEON Quad core CPUs, > 24 GB of RAM. I have searched around and I do not see anyone ever really > compare the two in terms of performance. I have learned from this thread > that Postgres needs a lot of configuration to perform the best. I think this is a pretty difficult question to answer. There are certainly people who are running databases on hardware like that - even databases much bigger than yours - on PostgreSQL - and getting acceptable performance. But it does take some work. In all fairness, I think that if you started on PostgreSQL and moved to MS SQL (or any other product), you'd probably need to make some adjustments going the other direction to get good performance, too. You're not going to compare two major database systems across the board and find that one of them is just twice as fast, across the board. They have different advantages and disadvantages. When you're using one product, you naturally do things in a way that works well for that product, and moving to a different product means starting over. Oh, putting this in a stored procedure was faster on MS SQL, but it's slower on PostgreSQL. Using a view here was terrible on MS SQL, but much faster under PostgreSQL. The real answer here is that anything could be true for your workload, and asking people on a mailing list to guess is a recipe for disappointment. You probably need to do some real benchmarking, and PostgreSQL will be slower at first, and you'll tune it, and it's LIKELY that you'll be able to achieve parity, or close enough that it's worth it to save the $$$. But you won't really know until you try it, I think. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance