Re: Restore v. Running COPY/INDEX seperatly

On Sun, 26 Aug 2007, Benjamin Arai wrote:

> Hi,
>
> So, I built my tables which contains a TSearch2 field by
>
> 1. Create table without indexes
> 2. COPY data into table
> 3. ALTER TABLE tblMessages ADD COLUMN idxFTI tsvector;
> 4. UPDATE tblMessages SET idxFTI=to_tsvector('default', strMessage);

vacuum here

> 5. Index all the fields including the TSearch2 field
>
> The process takes several days.
>
> In contrast, if I backup the table and restore it to a new table it takes a
> fraction of the time as running the above operation manually.  I am building
> my indexes at the end but I think the step 4 may be causing uneeded overhead.
> Can I somehow just copy data into the idxFTI field during the copy process?
> Is there anything else I can do to get my loading process to perform similar
> to backup/restore?
>
> Does pg_dump also dump the indexes?  That would explain why it is so much
> faster...
>
> Benjamin
>
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     Regards,
         Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83