Re: [GENERAL] [HACKERS] maintenance_work_mem and CREATE INDEX time

2013-07-23 Thread Jeff Janes
On Mon, Jul 22, 2013 at 9:11 PM, Amit Langote wrote: > Hello, > > While understanding the effect of maintenance_work_mem on time taken > by CREATE INDEX, I observed that for the values of > maintenance_work_mem less than the value for which an internal sort is > performed, the time taken by CREATE

Re: [GENERAL] [HACKERS] maintenance_work_mem and CREATE INDEX time

2013-07-23 Thread Jeff Janes
On Tue, Jul 23, 2013 at 1:23 AM, Amit Langote wrote: > On Tue, Jul 23, 2013 at 1:11 PM, Amit Langote wrote: >> Hello, >> >> While understanding the effect of maintenance_work_mem on time taken >> by CREATE INDEX, I observed that for the values of >> maintenance_work_mem less than the value for wh

Re: [GENERAL] [HACKERS] maintenance_work_mem and CREATE INDEX time

2013-07-23 Thread Amit Langote
On Wed, Jul 24, 2013 at 6:02 AM, Jeff Janes wrote: > On Tue, Jul 23, 2013 at 1:23 AM, Amit Langote wrote: >> On Tue, Jul 23, 2013 at 1:11 PM, Amit Langote >> wrote: >>> Hello, >>> >>> While understanding the effect of maintenance_work_mem on time taken >>> by CREATE INDEX, I observed that for t

Re: [GENERAL] [HACKERS] maintenance_work_mem and CREATE INDEX time

2013-07-23 Thread Amit Langote
On Wed, Jul 24, 2013 at 11:30 AM, Amit Langote wrote: > On Wed, Jul 24, 2013 at 6:02 AM, Jeff Janes wrote: >> If you are using trace_sort to report that, it reports the switch as >> happening as soon as it runs out of memory. >> >> At point, all we have been doing is reading tuples into memory.

Re: [GENERAL] [HACKERS] maintenance_work_mem and CREATE INDEX time

2013-07-23 Thread Amit Langote
On Wed, Jul 24, 2013 at 3:20 AM, Jeff Janes wrote: > On Mon, Jul 22, 2013 at 9:11 PM, Amit Langote wrote: >> Hello, >> >> While understanding the effect of maintenance_work_mem on time taken >> by CREATE INDEX, I observed that for the values of >> maintenance_work_mem less than the value for whic

Re: [GENERAL] [HACKERS] maintenance_work_mem and CREATE INDEX time

2013-07-29 Thread Jeff Janes
On Tue, Jul 23, 2013 at 10:56 PM, Amit Langote wrote: > On Wed, Jul 24, 2013 at 3:20 AM, Jeff Janes wrote: >> >> The heap structure used in external sorts is cache-unfriendly. The >> bigger the heap used, the more this unfriendliness becomes apparent. >> And the bigger maintenance_work_mem, the

Re: [GENERAL] [HACKERS] maintenance_work_mem and CREATE INDEX time

2013-07-29 Thread Amit Langote
Hi Jeff, On Tue, Jul 30, 2013 at 3:25 AM, Jeff Janes wrote: > On Tue, Jul 23, 2013 at 10:56 PM, Amit Langote > wrote: >> On Wed, Jul 24, 2013 at 3:20 AM, Jeff Janes wrote: >>> >>> The heap structure used in external sorts is cache-unfriendly. The >>> bigger the heap used, the more this unfrie