Hello !  

Do you have foreign keys on your tables ? And if so do you have indexes on
then ?  

A database with foreign keys and no indexes can run very slow for mas
insert/update/delete ?  

Cheers !  

?  
>  Tue Aug 18 2015 12:38:51 CEST from "Paolo Bolzoni"
><paolo.bolzoni.brown at gmail.com>  Subject: Re: [sqlite] ATTACH DATABASE
>statement speed
>
>  It really seems something strange happens at filesystem level.
> 
> This is a simple copy of slightly less than 1gb. It needs 9 seconds
> including sync.
> % date && sudo rsync -Pr italy-latest.osm.pbf / && sync && date
> Tue Aug 18 19:22:23 JST 2015
> sending incremental file list
> italy-latest.osm.pbf
> 946,976,283 100% 123.88MB/s 0:00:07 (xfr#1, to-chk=0/1)
> Tue Aug 18 19:22:32 JST 2015
> 
> 
> However, when I start sqlite3 db 'PRAGMA quick_check;' the IO looks
> normal for a while.
> (I hope gmail don't mess up with the formatting...)
> 
> 60, 90, 80 MB/s is kinda expected:
> 08/18/2015 07:27:38 PM
> Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s
> avgrq-sz avgqu-sz await r_await w_await svctm %util
> encplate
> 0.00 0.00 820.00 13.00 62.11 0.26
> 153.34 1.87 2.27 1.14 73.46 1.20 99.80
> 0.00 0.00 1214.50 0.00 94.58 0.00
> 159.49 0.96 0.78 0.78 0.00 0.78 95.20
> 0.00 0.00 1008.50 22.00 78.09 0.41
> 155.99 1.50 1.46 0.96 24.16 0.93 95.80
> 
> but after some seconds it drops terribly to less than 10MB/s
> 08/18/2015 07:29:04 PM
> Device: rrqm/s wrqm/s r/s w/s rMB/s wMB/s
> avgrq-sz avgqu-sz await r_await w_await svctm %util
> encplate
> 0.00 0.00 124.00 3.50 9.88 0.12
> 160.72 1.67 12.99 11.21 76.14 7.65 97.50
> 0.00 0.00 69.00 18.00 5.68 0.29
> 140.55 1.81 20.92 14.15 46.86 11.38 99.00
> 0.00 0.00 86.00 0.00 7.05 0.00
> 167.91 1.04 12.03 12.03 0.00 11.24 96.70
> 
> And so, going to 10MB per second it can easily require few hours...
> 
> 
> I am out of ideas, but thanks for all the support.
> 
> 
> 
> On Tue, Aug 18, 2015 at 7:26 PM, Simon Slavin <slavins at bigfraud.org> wrote:
> 
>  
>>On 18 Aug 2015, at 7:30am, Paolo Bolzoni <paolo.bolzoni.brown at gmail.com>
>>wrote:
>> 
>>  
>>>Any other idea of what can I try? Perhaps my filesystem is misconfigured?
>>> 

>>  The long time you quote is not standard for SQLite and I don't think
>>anyone can help you solve it by knowing picky details of SQLite. I'm even
>>surprised that it changed with your -O0 compilation since this suggests
>>features of your compiler I didn't know about.
>> 
>> It's possible one of the developer team can help but they're reading this
>>and can pitch in if they think so.
>> 
>> Simon.
>> _______________________________________________
>> sqlite-users mailing list
>> sqlite-users at mailinglists.sqlite.org
>> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users

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