Re: Full-text search default vs specified configuration

Tom Lane wrote:
> Richard Huxton <dev@archonet.com> writes:
>> Would there be any support for two changes in 8.4 though?
> 
>> 1. Tag tsvector/tsquery's with the (oid of) their configuration?
> 
>> 2. Either warn or require CASCADE on changes to a 
>> configuration/dictionary that could impact existing indexes etc.
> 
> IIRC, the current behavior is intentional --- Oleg and Teodor argued
> that tsvector values are relatively independent of small changes in
> configuration and we should *not* force people to, say, reindex their
> tables every time they add or subtract a stopword.  If we had some
> measure of whether a TS configuration change was "critical" or not,
> it might make sense to restrict critical changes; but I fear that
> would be kind of hard to determine.

Well, clearly in my example it didn't impact operation at all, but it's 
an accident waiting to happen (and more importantly, a hard one to track 
down). It's like running SQL-ASCII encoding, everything just ticks along 
only to cause problems a month later.

What about the warning: "This may affect existing indexes - please 
check". Would that cause anyone problems?

What worries me is that it might take 10 messages on general/sql list to 
figure out the problem. This was reported as "words with many hits 
causes problems".

Maybe it's just a matter of getting the message out: "always specify the 
config or never specify the config".

--   Richard Huxton  Archonet Ltd