Re: [PERFORM] about multiprocessingmassdata

2012-04-10 Thread Merlin Moncure
On Mon, Apr 9, 2012 at 6:50 PM, Tomas Vondra wrote: > On 10.4.2012 00:37, Merlin Moncure wrote: >> On Thu, Apr 5, 2012 at 9:47 AM, Tomas Vondra wrote: >>> If you have slower drives, the dependency is about linear (half the >>> speed -> twice the time). So either your drives are very slow, or >>>

Re: [PERFORM] about multiprocessingmassdata

2012-04-09 Thread Tomas Vondra
On 10.4.2012 00:37, Merlin Moncure wrote: > On Thu, Apr 5, 2012 at 9:47 AM, Tomas Vondra wrote: >> If you have slower drives, the dependency is about linear (half the >> speed -> twice the time). So either your drives are very slow, or >> there's something rotten. >> >> I still haven's seen iostat

Re: [PERFORM] about multiprocessingmassdata

2012-04-09 Thread Merlin Moncure
On Thu, Apr 5, 2012 at 9:47 AM, Tomas Vondra wrote: > On 5.4.2012 15:44, superman0920 wrote: >> Sure, i will post that at tomorrow. >> >> Today I install PG and MySQL at a  Server. I insert 85 rows record >> to each db. >> I execute "select count(*) from poi_all_new" at two db. >> MySQL takes

Re: [PERFORM] about multiprocessingmassdata

2012-04-05 Thread Kevin Grittner
Tomas Vondra wrote: > On 5.4.2012 15:44, superman0920 wrote: >> Today I install PG and MySQL at a Server. I insert 85 rows >> record to each db. >> I execute "select count(*) from poi_all_new" at two db. >> MySQL takes 0.9s >> PG takes 364s > Are you sure the comparison was fair, i.e. bot

Re: [PERFORM] about multiprocessingmassdata

2012-04-05 Thread Tomas Vondra
On 5.4.2012 15:44, superman0920 wrote: > Sure, i will post that at tomorrow. > > Today I install PG and MySQL at a Server. I insert 85 rows record > to each db. > I execute "select count(*) from poi_all_new" at two db. > MySQL takes 0.9s > PG takes 364s First of all, keep the list (pgsql-pe

Re: [PERFORM] about multiprocessingmassdata

2012-04-04 Thread Tomas Vondra
On 4.4.2012 18:49, superman0920 wrote: > Thank you for your reply > I tried executing "UPDATE poi SET py = replace(py, ' ','');", that took > long long time(about 20+ hours) and no error report. Just like locked. OK, that's weird. So we need a bit more details - what PostgreSQL version is this?

Re: [PERFORM] about multiprocessingmassdata

2012-04-04 Thread Tomas Vondra
On 4.4.2012 17:52, superman0920 wrote: > Hi list! > > i have a table which has 850 rows records. i write a java program to > update these records. > i use 100 threads to update the records. For example, thread-1 update > 1~85000 records; thread-2 update 85001~17 and so on. > The update sql'

[PERFORM] about multiprocessingmassdata

2012-04-04 Thread superman0920
Hi list! i have a table which has 850 rows records. i write a java program to update these records. i use 100 threads to update the records. For example, thread-1 update 1~85000 records; thread-2 update 85001~17 and so on. The update sql's aim is remove the space in the column and it is