On Mar 4, 2011, at 4:07 PM, Ture Pålsson wrote: > 2011/3/4 Rosemary Alles <rosemary.al...@gmail.com>: >> Hullo all, >> >> I'm attempting to store several sets of GPS derived spatial data (simple >> lat/lon mostly) in PostGIS and have hence installed PostgreSQL with the >> PostGIS extension on my iMac (running 10.6.6), the readme that comes with >> the PostgreSQL (at least for the latest version of it) casually warns of the >> need to increase -significantly- the amounts of shared memory availalbe for >> use. (See "attached" readme) Has anyone done this and what are the risks? > > I played around with that a few months ago, and with my test case, > pulling an Openstreetmap extract of Sweden into the database on a 2 > GByte iMac, I could not get any measurable performance improvement by > increasing Postgres's shared-memory parameters. It seems that the > OS-level buffer cache is doing a decent job. The obvious criticism > against this test case is that it has a single database "user" > executing a few large transactions which may not be a realistic > scenario. Then again, I don't think there are any major risks changing > the system coniguration as long as you stick to the recommended values > and always think twice before hitting "return".
It's not really a "warning" about any potential problem. It's an installation recommendation/requirement. With the OS X defaults the Postgres server may not run at all, especially with large and/or many databases, and on 64bit processors. It doesn't hurt the system. Odd, I thought I had that info in my package readme. I'll have to dig through my memory and notes to see why I removed it, or if it was accidental. ----- William Kyngesburye <kyngchaos*at*kyngchaos*dot*com> http://www.kyngchaos.com/ "Time is an illusion - lunchtime doubly so." - Ford Prefect _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
