Folks, Subsequent to my presentation of the new annotated.conf at pgCon last week, there's been some argument about the utility of certain memory settings above 2GB. I'd like to hash those out on this list so that we can make some concrete recomendations to users. shared_buffers: according to witnesses, Greg Smith presented at East that based on PostgreSQL's buffer algorithms, buffers above 2GB would not really receive significant use. However, Jignesh Shah has tested that on workloads with large numbers of connections, allocating up to 10GB improves performance. sort_mem: My tests with 8.2 and DBT3 seemed to show that, due to limitations of our tape sort algorithm, allocating over 2GB for a single sort had no benefit. However, Magnus and others have claimed otherwise. Has this improved in 8.3? So, can we have some test evidence here? And workload descriptions? -- --Josh Josh Berkus PostgreSQL @ Sun San Francisco
