Re: LIKE indexing proposal - Mailing list pgsql-hackers

From Zeugswetter Andreas SB SD
Subject Re: LIKE indexing proposal
Date
Msg-id 46C15C39FEB2C44BA555E356FBCD6FA4961FAC@m0114.s-mxs.net
Whole thread Raw
In response to LIKE indexing proposal  (Peter Eisentraut <peter_e@gmx.net>)
List pgsql-hackers
> You've apparently forgotten all our previous history on that subject
> :-(.  The above does not work in the presence of special sort rules for
> digraphs, etc.  For example, that LIKE should certainly match ABCH ...
> but there are locales in which "CH" sorts after "D" and would not be
> found by an indexscan that runs from ABC to ABD.

Sorry, so is the start condition of >= 'ABC' also not valid ?

A new index scan method with the pattern as input would need to know when it can
safely stop (which is the problem I understand), but would have the advantage of
beeing able to filter unwanted tuples before the heap access.

Andreas



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