tv@xxxxxxxx írta: >> Hi, >> >> I got a question about scalability in high volume insert situation >> where the table has a primary key and several non-unique indexes >> on other columns of the table. How does PostgreSQL behave >> in terms of scalability? The high volume of inserts comes from >> multiple transactions. >> >> Best regards, >> Zoltán Böszörményi >> > > Well, that's a difficult question as it depends on hardware and software, > but with a proper tunning the results may be very good. Just do the basic > PostgreSQL tuning and then tune it for the INSERT performance if needed. > It's difficult to give any other recommendations without a more detailed > knowledge of the problem, but consider these hints: > > 1) move the pg_xlog to a separate drive (so it's linear) > 2) move the table with large amount of inserts to a separate tablespace > 3) minimize the amount of indexes etc. > > The basic rule is that each index adds some overhead to the insert, but it > depends on datatype, etc. Just prepare some data to import, and run the > insert with and without the indexes and compare the time. > > Tomas > Thanks. The question is more about theoretical working. E.g. if INSERTs add "similar" records with identical index records (they are non-unique indexes) does it cause contention? Because these similar records add index tuples that supposed to be near to each other in the btree. -- ---------------------------------- Zoltán Böszörményi Cybertec Schönig & Schönig GmbH http://www.postgresql.at/
