Обсуждение: PostgreSQL is extremely slow on Windows
Hi,
I've downloaded the latest release (PostgreSQL 8.0) for windows.
Installation was OK, but I have tried to restore a database.
It had more than ~100.000 records. Usually I use PostgreSQL
under Linux, and it used to be done under 10 minutes.
Under W2k und XP it took 3 hours(!) Why is it so slow????
The commands I used:
Under Linux: (duration: 1 minute)
pg_dump -D databasename > databasename.db
Under Windows: (duration: 3 - 3.5 hours(!))
psql databasename < databasename.db >nul
It seemed to me, that only 20-30 transactions/sec were
writen to the database.
I need to write scripts for automatic (sheduled) database
backup and recovery.
Help anyone?
Bye,
Vig Sándor
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On Tue, 22 Feb 2005 16:00:59 +0100, Vig, Sandor (G/FI-2) <Sandor.Vig@audi.hu> wrote: > > > Hi, > > I've downloaded the latest release (PostgreSQL 8.0) for windows. > Installation was OK, but I have tried to restore a database. > It had more than ~100.000 records. Usually I use PostgreSQL > under Linux, and it used to be done under 10 minutes. > > Under W2k und XP it took 3 hours(!) Why is it so slow???? Can you tell us your postgresql.conf configuration settings? We cannot help without some information about your environment... -- Mitch
>I've downloaded the latest release (PostgreSQL 8.0) for windows. >Installation was OK, but I have tried to restore a database. >It had more than ~100.000 records. Usually I use PostgreSQL >under Linux, and it used to be done under 10 minutes. > >Under W2k und XP it took 3 hours(!) Why is it so slow???? > >The commands I used: > >Under Linux: (duration: 1 minute) > pg_dump -D databasename > databasename.db > >Under Windows: (duration: 3 - 3.5 hours(!)) > psql databasename < databasename.db >nul > >It seemed to me, that only 20-30 transactions/sec were >writen to the database. 20-30 transactionsi s about what you'll get on a single disk on Windows today. We have a patch in testing that will bring this up to about 80. You can *never* get above 80 without using write cache, regardless of your OS, if you have a single disk. You might want to look into wether write cacheing is enabled on your linux box, and disable it. (unless you are using RAID) A lot points towards write cache enabled on your system. If you need the performance that equals the one with write cache on, you can set fsync=off. But then you will lose the guarantee that your machine will survive an unclean shutdown or crash. I would strongly advice against it on a production system - same goes for running with write cache! //Magnus
Magnus Hagander wrote: > You can *never* get above 80 without using write cache, regardless of > your OS, if you have a single disk. Why? Even with, say, a 15K RPM disk? Or the ability to fsync() multiple concurrently-committing transactions at once? -Neil
Hi, Magnus & all, Magnus Hagander schrieb: > 20-30 transactionsi s about what you'll get on a single disk on Windows > today. > We have a patch in testing that will bring this up to about 80. > You can *never* get above 80 without using write cache, regardless of > your OS, if you have a single disk. You might want to look into wether > write cacheing is enabled on your linux box, and disable it. (unless you > are using RAID) A lot points towards write cache enabled on your system. Note that you can get higher rates for the server as a whole when using concurrent transactions (that is, several independend connections committing at the same time). The commit delay settings should be tuned accordingly. Markus -- markus schaber | dipl. informatiker logi-track ag | rennweg 14-16 | ch 8001 zürich phone +41-43-888 62 52 | fax +41-43-888 62 53 mailto:schabios@logi-track.com | www.logi-track.com