Thread: Re: [HACKERS] All things equal, we are still alot slower then MySQL?
Tom Lane <tgl@sss.pgh.pa.us> writes: >>>> MySQL: 0.498u 0.150s 0:02.50 25.6% 10+1652k 0+0io 0pf+0w >>>> PgSQL: 0.494u 0.061s 0:19.78 2.7% 10+1532k 0+0io 0pf+0w > >> No --- if he were, it'd be all CPU time, not 2.7% CPU usage. > >Er, wait a second. Are we measuring backend-process runtime here, >or is that the result of 'time' applied to a *client* ? Yeah, that would explain a lot. When I first saw the numbers, I was so excited because they showed that PostgreSQL is *faster* than MySQL (with more memory, and better I/O). That didn't make any sense, though. MySQL is faster than every real DBMS, because it doesn't have transactions, triggers, locking, or any other sort of useful features to slow it down. The question should always be, is PostgreSQL faster than Oracle, Informix, or Sybase? -Michael
> Tom Lane <tgl@sss.pgh.pa.us> writes: > >>>> MySQL: 0.498u 0.150s 0:02.50 25.6% 10+1652k 0+0io 0pf+0w > >>>> PgSQL: 0.494u 0.061s 0:19.78 2.7% 10+1532k 0+0io 0pf+0w > > > >> No --- if he were, it'd be all CPU time, not 2.7% CPU usage. > > > >Er, wait a second. Are we measuring backend-process runtime here, > >or is that the result of 'time' applied to a *client* ? > > Yeah, that would explain a lot. When I first saw the numbers, I was so > excited because they showed that PostgreSQL is *faster* than MySQL (with > more memory, and better I/O). > > That didn't make any sense, though. MySQL is faster than every real DBMS, > because it doesn't have transactions, triggers, locking, or any other sort > of useful features to slow it down. > > The question should always be, is PostgreSQL faster than Oracle, Informix, > or Sybase? I am told we are the same as Ingres, and slower than Oracle with no -F, and faster than Oracle with -F. -- Bruce Momjian | http://www.op.net/~candle maillist@candle.pha.pa.us | (610) 853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania19026
> I am told we are the same as Ingres, and slower than Oracle with no -F, > and faster than Oracle with -F. What is "-F"? -- Chris Bitmead mailto:chris@tech.com.au
> > > I am told we are the same as Ingres, and slower than Oracle with no -F, > > and faster than Oracle with -F. > > What is "-F"? > -F is postgres option for no-fsync. -- Bruce Momjian | http://www.op.net/~candle maillist@candle.pha.pa.us | (610) 853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania19026
Chris Bitmead ha scritto: > > I am told we are the same as Ingres, and slower than Oracle with no -F, > > and faster than Oracle with -F. > > What is "-F"? > from man postgres: -F Disable an automatic fsync() call after each trans action. This option improves performance, butan operating system crash while a transaction is in progress may cause the loss of the mostrecently entered data. Without the fsync() call the data is buffered by the operating system,and written to disk sometime later. José
Re: [HACKERS] All things equal, we are still alot slower then MySQL?
From
les@Mars.mcs.net (Leslie Mikesell)
Date:
In article <199909201327.JAA18590@candle.pha.pa.us>, Bruce Momjian <maillist@candle.pha.pa.us> wrote: >> >> > I am told we are the same as Ingres, and slower than Oracle with no -F, >> > and faster than Oracle with -F. >> >> What is "-F"? >> > >-F is postgres option for no-fsync. Does that matter on read-only selects? Might some future version of postgresql have an option to turn off transaction support to match mysql speed for the situations where that is more important than the ability to roll back? Les Mikesell les@mcs.com