Re: Equivalent praxis to CLUSTERED INDEX? - Mailing list pgsql-performance

From Mischa Sandberg
Subject Re: Equivalent praxis to CLUSTERED INDEX?
Date
Msg-id FSsXc.56332$X12.9135@edtnps84
Whole thread Raw
In response to Re: Equivalent praxis to CLUSTERED INDEX?  ("J. Andrew Rogers" <jrogers@neopolitan.com>)
List pgsql-performance
Sheer nitpick here...

A B-tree is where the records (data) live at all levels of the tree;
B+ tree is where the records are only at the leaf level.
That's what Knuth calls them, anyway.

Clustered indexes for all known dbs are true B+ trees.
Nonclustered indexes could be B-trees (probably aren't),
since there's no big fanout penalty for storing the little
(heap) row locators everywhere at all levels.

J. Andrew Rogers wrote:
> As far as I know, Oracle does it by having a B-Tree organized heap (a
> feature introduced around v8 IIRC), basically making the primary key
> index and the heap the same physical structure.
...

pgsql-performance by date:

Previous
From: Mischa Sandberg
Date:
Subject: Re: Equivalent praxis to CLUSTERED INDEX?
Next
From: "Jack Kerkhof"
Date:
Subject: Why does a simple query not use an obvious index?