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Re: can't handle large number of INSERT/UPDATEs

From: "Anjan Dave" <adave(at)vantage(dot)com>
To: "Rod Taylor" <pg(at)rbt(dot)ca>
Cc: "Postgresql Performance" <pgsql-performance(at)postgresql(dot)org>
Subject: Re: can't handle large number of INSERT/UPDATEs
Date: 2004-10-26 17:56:25
Message-ID: 4BAFBB6B9CC46F41B2AD7D9F4BBAF7850985DD@vt-pe2550-001.vantage.vantage.com (view raw or flat)
Thread:
Lists: pgsql-performance
None of the locks are in state false actually.

I don't have iostat on that machine, but vmstat shows a lot of writes to
the drives, and the runnable processes are more than 1:

procs                      memory      swap          io     system
cpu
 r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy
wa id
 1  2      0 3857568 292936 2791876    0    0     0 44460 1264  2997 23
13 22 41
 2  2      0 3824668 292936 2791884    0    0     0 25262 1113  4797 28
12 29 31
 2  3      0 3784772 292936 2791896    0    0     0 38988 1468  6677 28
12 48 12
 2  4      0 3736256 292936 2791904    0    0     0 50970 1530  5217 19
12 49 20
 4  2      0 3698056 292936 2791908    0    0     0 43576 1369  7316 20
15 35 30
 2  1      0 3667124 292936 2791920    0    0     0 39174 1444  4659 25
16 35 24
 6  1      0 3617652 292936 2791928    0    0     0 52430 1347  4681 25
19 20 37
 1  3      0 3599992 292936 2790868    0    0     0 40156 1439  4394 20
14 29 37
 6  0      0 3797488 292936 2568648    0    0     0 17706 2272 21534 28
23 19 30
 0  0      0 3785396 292936 2568736    0    0     0  1156 1237 14057 33
8  0 59
 0  0      0 3783568 292936 2568736    0    0     0   704  512  1537  5
2  1 92
 1  0      0 3783188 292936 2568752    0    0     0   842  613  1919  6
1  1 92

-anjan

-----Original Message-----
From: Rod Taylor [mailto:pg(at)rbt(dot)ca] 
Sent: Tuesday, October 26, 2004 1:49 PM
To: Anjan Dave
Cc: Postgresql Performance
Subject: RE: [PERFORM] can't handle large number of INSERT/UPDATEs

On Tue, 2004-10-26 at 13:42, Anjan Dave wrote:
> It probably is locking issue. I got a long list of locks held when we
ran select * from pg_locks during a peak time.
> 
> relation | database | transaction |  pid  |       mode       | granted

>
----------+----------+-------------+-------+------------------+---------
>     17239 |    17142 |             |  3856 | AccessShareLock  | t

How many have granted = false?

> Vmstat would show a lot of disk IO at the same time.
> 
> Is this pointing towards a disk IO issue?

Not necessarily. Is your IO reaching the limit or is it just heavy?



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Next:From: Josh BerkusDate: 2004-10-26 18:27:02
Subject: Re: can't handle large number of INSERT/UPDATEs
Previous:From: Rod TaylorDate: 2004-10-26 17:48:42
Subject: Re: can't handle large number of INSERT/UPDATEs

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