Re: Scan by TID (was RE: [HACKERS] How to add a new build-in operator) - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Scan by TID (was RE: [HACKERS] How to add a new build-in operator)
Date
Msg-id 199910111914.PAA00307@candle.pha.pa.us
Whole thread Raw
In response to Re: Scan by TID (was RE: [HACKERS] How to add a new build-in operator)  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses RE: Scan by TID (was RE: [HACKERS] How to add a new build-in operator)
List pgsql-hackers
> "Hiroshi Inoue" <Inoue@tpf.co.jp> writes:
> > Yes,I have done a part of my story.
> > I would add new type of path and scan by which we are able to access
> > tids directly.
> 
> Yes, new path type, new plan type, probably a new access method if
> you want to keep things clean in the executor, cost-estimation routines
> in the planner, etc. etc.
> 
> Looks like a lot of work, and a lot of added code bulk that will
> have to be maintained.  I haven't figured out why you think it's
> worth it... tids are so transient that I don't see much need for
> finding tuples by them...

That's why I just suggested a more short-circuited option of snatching
tid oids from expressions, and doing a heap_fetch directly at that point
to avoid the index scan.  Seems it could be done in just one file.

--  Bruce Momjian                        |  http://www.op.net/~candle maillist@candle.pha.pa.us            |  (610)
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