Re: [HACKERS] Full-text search default vs specified configuration

2008-02-22 Thread Tom Lane
Richard Huxton [EMAIL PROTECTED] 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.

regards, tom lane

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Re: [HACKERS] Full-text search default vs specified configuration

2008-02-22 Thread Richard Huxton

Tom Lane wrote:

Richard Huxton [EMAIL PROTECTED] 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

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Re: [HACKERS] Full-text search default vs specified configuration

2008-02-22 Thread Oleg Bartunov

On Fri, 22 Feb 2008, Richard Huxton wrote:


Tom Lane wrote:

Richard Huxton [EMAIL PROTECTED] 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.


He just didn't read documentation thoroughly.



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


Probably, just stress this in documentation.


Regards,
Oleg
_
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: [EMAIL PROTECTED], http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83

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