Re: Full vacuuming of BIG tables takes too long

Hello Thierry,

Thursday, May 22, 2003, 5:45:26 PM, you wrote:

TM> Hi,

TM> I don't have a solution but :
TM> 1) Is your system spending time in Wait I/O, while vacuum analyze is running
TM> ?
Almost no. During fist 30 mins summary I/O (iostat 1) is 20/25
megs/sec, then only 3-5 megs/sec. the "i/o wait" counters in cpu
activity are not too high.

TM> Perhaps, you can save time by incrising I/O throughput.
I.e. to use SCSI-HDD ? 8)) May be. But I stall hope tha the problem
can be solved by increasing memory/tuning initialization parameters...

TM> 2) In the alternative dump/recreate/restore, do you recreate the Foreign Key
TM> ? This step takes long time (depending of your Database schema). I have try
TM> this scenario :
TM> Dump data / Drop Foreign Key / Truuncate Tables / restore / Recreate the
TM> Foreign Key
TM> The step Recreate FK takes 2 times the four first steps.
I don't use foreign keys. Only primary keys. There is only 3 tables in
that db. 99% of space is taken by one table.

--
Best regards,
Eugene mailto:emz(at)norma(dot)perm(dot)ru