On Wednesday 04 April 2007 07:51, Arnau wrote: > Hi Ansgar , > > > On 2007-04-04 Arnau wrote: > >> Josh Berkus wrote: > >>>> Is there anything similar in PostgreSQL? The idea behind this is how > >>>> I can do in PostgreSQL to have tables where I can query on them very > >>>> often something like every few seconds and get results very fast > >>>> without overloading the postmaster. > >>> > >>> If you're only querying the tables every few seconds, then you don't > >>> really need to worry about performance. > >> > >> Well, the idea behind this is to have events tables, and a monitoring > >> system polls that table every few seconds. I'd like to have a kind of > >> FIFO stack. From "the events producer" point of view he'll be pushing > >> rows into that table, when it's filled the oldest one will be removed > >> to leave room to the newest one. From "the consumer" point of view > >> he'll read all the contents of that table. > >> > >> So I'll not only querying the tables, I'll need to also modify that > >> tables. > > > > Ummm... this may be a dumb question, but why are you trying to implement > > something like a FIFO with an RDBMS in the first place? Wouldn't it be > > much easier to implement something like that as a separate program or > > script? > > Well, the idea is have a table with a maximum number of rows. As the > number of queries over this table will be very high, I'd like to keep it > as small as possible and without indexes and so on that could make the > update slower. > > Maybe it's the moment to change my question, is there any trick to get a > table that can be modified/queried very fast and with the minimum of > overhead? This table will have several queries every second and I'd like > to do this as fast as possible > If you're wedded to the FIFO idea, I'd suggest reading this: http://people.planetpostgresql.org/greg/index.php?/archives/89-Implementing-a-queue-in-SQL-Postgres-version.html -- Robert Treat Build A Brighter LAMP :: Linux Apache {middleware} PostgreSQL
