Re: btree information - Mailing list pgsql-admin

From Alvaro Herrera
Subject Re: btree information
Date
Msg-id 20050607195743.GC19846@surnet.cl
Whole thread Raw
In response to btree information  (Eduardo Bezerra <edubezval@gmail.com>)
Responses Re: btree information  (Eduardo Bezerra <edubezval@gmail.com>)
List pgsql-admin
On Tue, Jun 07, 2005 at 01:36:56PM -0400, Eduardo Bezerra wrote:
> hi all,
>  Someone can help me to find these data about btree index:
>   * height;
>  * maximum number of keys per block
>  * average number of keys per block
>  * number of leaf blocks
>  * average number of leaf blocks per total number of keys
>  * average number of data blocks per total number of keys

I guess what I'd do is run pg_filedump in an btree index file to find
out.  Leaf pages are marked with the BTP_LEAF flag.

Regarding the number of keys in a block, it's variable, depends on the
size of the keys.  You can find out for a particular index using
pg_filedump too.

--
Alvaro Herrera (<alvherre[a]surnet.cl>)
Jude: I wish humans laid eggs
Ringlord: Why would you want humans to lay eggs?
Jude: So I can eat them

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