Horton

Re: WIP: index support for regexp search

Alexander Korotkov <aekorotkov@gmail.com>

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From: Alexander Korotkov <aekorotkov@gmail.com>
To: Heikki Linnakangas <hlinnakangas@vmware.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Tomas Vondra <tv@fuzzy.cz>, Erik Rijkers <er@xs4all.nl>, pgsql-hackers@postgresql.org, pavel.stehule@gmail.com
Date: 2012-12-16T21:25:06Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Fix filling of postmaster.pid in bootstrap/standalone mode.

  2. Add explicit casts in ilist.h's inline functions.

Attachments

On Fri, Dec 14, 2012 at 1:34 AM, Alexander Korotkov <aekorotkov@gmail.com>wrote:

> On Mon, Dec 3, 2012 at 4:31 PM, Alexander Korotkov <aekorotkov@gmail.com>wrote:
>
>> Actually, I generally dislike path matrix for same reasons. But:
>> 1) Output graphs could contain trigrams which are completely useless for
>> search. For example, for regex /(abcdefgh)*ijk/ we need only "ijk" trigram
>> while graph would contain much more.Path matrix is a method to get rid of
>> all of them.
>> 2) If we use color trigrams then we need some criteria for which color
>> trigrams to expand into trigrams. Simultaneously, we shouldn't allow path
>> from initial state to the final by unexpanded trigrams. It seems much
>> harder to do with graph than with matrix.
>>
>
> Now, I have an idea about doing some not comprehensive but simple and fast
> simplification of graph. I'm doing experiments now. In case of success we
> could get rid of path matrix.
>

Attached patch have following changes:
1) Postphone expansion of colors. Graph are building on color trigrams.
2) Selective expansion of color trigrams into simple trigrams. All
non-expanded color trigrams are removed. Such removal leads to union of all
states pairs connected with corresponding arcs. Surely, this must no lead
to union of initial and final states: that could do all previous work
senseless.

------
With best regards,
Alexander Korotkov.