Re: tsvector/tsearch equality and/or portability issue - Mailing list pgsql-hackers

From Tom Lane
Subject Re: tsvector/tsearch equality and/or portability issue
Date
Msg-id 18800.1156802268@sss.pgh.pa.us
Whole thread Raw
In response to Re: tsvector/tsearch equality and/or portability issue  (Phil Frost <indigo@bitglue.com>)
Responses Re: tsvector/tsearch equality and/or portability issue
List pgsql-hackers
Phil Frost <indigo@bitglue.com> writes:
> Things still seem to be broken for me. Among other things, the script at
> <http://unununium.org/~indigo/testvectors.sql.bz2> fails. It performs two
> tests, comparing 1000 random vectors with positions and random weights, and
> comparing the same vectors, but stripped. Oddly, the unstripped comparisons all
> pass, which is not consistant with what I am seeing in my database. However,
> I'm yet unable to reproduce those problems.

It looks to me like tsvector comparison may be too strong.  The strip()
function evidently thinks that it's OK to rearrange the string chunks
into the same order as the WordEntry items, which suggests to me that
the "pos" fields are not really semantically significant.  But 
silly_cmp_tsvector() considers that a difference in pos values is
important.  I don't understand the data structure well enough to know
which one to believe, but something's not consistent here.
        regards, tom lane


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