Re: Max size of a btree index entry

From: Josh Berkus <josh(at)agliodbs(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-hackers(at)postgreSQL(dot)org
Subject: Re: Max size of a btree index entry
Date: 2006-07-11 14:46:34
Message-ID: 44B3B9CA.20903@agliodbs.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Tom,

> Obviously a tree containing many such pages would be awfully inefficient
> to search, but I think a more common case is that there are a few wide
> entries in an index of mostly short entries, and so pushing the hard
> limit up a little would add some flexibility with little performance
> cost in real-world cases.
>
> Have I missed something? Is this worth changing?

Not sure. I don't know that the difference between 2.7K and 3.9K would
have ever made a difference to me in any real-world case.

If we're going to tinker with this code, it would be far more valuable
to automatically truncate b-tree entries at, say, 1K so that they could
be efficiently indexed.

Of course, a quick archives search of -SQL, -Newbie and -General would
indicate how popular of an issue this is.

--Josh Berkus

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Dave Page 2006-07-11 14:47:20 Re: Three weeks left until feature freeze
Previous Message Josh Berkus 2006-07-11 14:32:39 Re: Three weeks left until feature freeze