Re: select single entry and its neighbours using direct-acess to index?

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Pierre-Frédéric Caillaud
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Re: select single entry and its neighbours using direct-acess to index?
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opsilfna03cq72hf@musicbox
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Re: select single entry and its neighbours using direct-acess to index? Andrew - Supernews <andrew+nonews@supernews.com>
Re: select single entry and its neighbours using direct-acess to index? Pierre-Frédéric Caillaud<lists@boutiquenumerique.com>
Re: select single entry and its neighbours using direct-acess to index? Tom Lane <tgl@sss.pgh.pa.us>
Re: select single entry and its neighbours using direct-acess to index? Pierre-Frédéric Caillaud<lists@boutiquenumerique.com>
Re: select single entry and its neighbours using direct-acess to index? Greg Stark <gsstark@mit.edu>

>> 	I thought the planner had an automatic rewriter for these situations.
>
> No.  There was a prior discussion of this, saying that we really ought
> to support the SQL-spec row comparison syntax:

	What I meant was that I thought the planner could rewrite :
	(A and C) or (A AND B) as A and (B or C)
	which is more index-friendly.

> 	... WHERE (name, name2) > ('b', 'a');
> which would map directly onto the semantics of a 2-column index.  We
> don't have that functionality yet, though (we take the syntax but the
> semantics are not SQL-compliant) let alone any ability to pass it
> through to a 2-column index.

	One could always use ARRAY[name,name2] > ARRAY['b','a']
	But it is NOT index-friendly...
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