> > TODO list updated. Seems the tid could be accessed directly, by
> > checking the page list, and if it is valid, just going to the tid. I
> > assume you are working on that issue, or do you need assistance?
> >
>
> 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.
>
> I don't understand planner/executor stage well.
> So I'm happy if someone could check my story.
My guess is that you are going to have to hard-code something into the
backend to handle non-scan lookup of this type specially.
Normally, either there is an index lookup, or a sequential scan. In
your case, you "know" the actual location of the row, or at least a
request for a possible valid location.
You could create a fake index that really doesn't exist, but returns a
tid that exactly matches the requested tid, or you could have the code
check for a specific TID type, and heap_fetch the desired row directly,
rather than performing a sequential scan. See the developers FAQ on how
to do a heap_fetch with a tid.
You can also use <I>heap_fetch()</I> to fetch rows by blocknumber/offset.
The block number/offset is the tid. Of course, you have to make sure
the tid is valid.
-- Bruce Momjian | http://www.op.net/~candle maillist@candle.pha.pa.us | (610)
853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill,
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