On Jan 29, 2010, at 10:52 PM, Yannick Gingras wrote:

>> 
>> I usually go with the IN clause but I wonder if its possible to
>> write PG stored procedures that can get to xapian as well (since you
>> can write them in python or any other language).
> 
> I would not be too hard to make it run on in PL/Python but PL/Python
> is a non-safe language so it's a bit of a pain to have new versions of
> the proc deployed since you need to admin in PG to update it.  This is
> why I'd rather go with a solution on the client side.
> 
> When you go with the big IN, you sort by full text ranking on the
> Python side?  This forces you to fetch the full result set to have the
> desired page.  My experience is that the IN solution get unbearably
> slow quite fast.  With 40000+ results from Xapian, it can take several
> seconds to get my results with IN.  I doubt that any sane human will
> go through all those 40k results so it's probably safe to only send
> the first fer thousands full text ids to the database but our
> requirements call for an accurate page count.  

the IN is only used to add extra information for display purposes, so is 
typically on a pageful at at time.  anything you're filtering or sorting on 
needs to be indexed on the search engine side.



> 
> The more I think about it, the more it looks like the stored proc in
> PL/Python is the only same way to do it.
> 
> Thank again for all the infos.
> 
> -- 
> Yannick Gingras
> http://ygingras.net
> http://confoo.ca -- track coordinator
> http://montrealpython.org -- lead organizer

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