Re: Simplifying Text Search

"Peter Eisentraut" <peter_e(at)gmx(dot)net> writes:

> What we'd need is a way to convert a LIKE pattern into a tsquery ('%foo%bar%'
> => 'foo & bar'). Then you might even be able to sneak index-optimized text
> search into existing applications. Might be worth a try.

I don't think that's the right direction to go. Notably "%foo%bar%" isn't the
same thing as "foo & bar". Also most tsearch queries can't be expressed as
LIKE patterns anyways.

What I do like is the idea of using LIKE as a model to follow for tsearch.
Make some keyword which maps to an operator. So you could do something like

WHERE col SATISFIES 'foo & bar'

which maps to @@ just as LIKE maps to ~~. This has the interesting property of
working for ltree and other data types which support the @@ operator.

Now I'm starting to wonder though. How evil would it be to just rename all the
@@ operators to ~~ ? That redefines LIKE to be a data-type-specific operation.
Effectively declaring that tsquery, lquery, et al are all analogous concepts
for LIKE patterns.

It's probably safer to come up with a new keyword for @@ and if we ever decide
to pursue a regexp data type we could define @@ for that as well which would
make that keyword an equivalent to LIKE for regexps.

--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com
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