Re: How to force Nested Loop plan? - Mailing list pgsql-performance

From Tom Lane
Subject Re: How to force Nested Loop plan?
Date
Msg-id 10675.1062450197@sss.pgh.pa.us
Whole thread Raw
In response to Re: How to force Nested Loop plan?  (Ron Johnson <ron.l.johnson@cox.net>)
List pgsql-performance
Ron Johnson <ron.l.johnson@cox.net> writes:
> How about (if you don't already do it) ranked (or approximately
> ranked) b-tree indexes, where each node also stores the (approximate)
> count of tuple pointers under it?
> This way, the planner would know whether or how skewed a tree is,
> and (approximately) how many tuples a given WHERE predicate resolves
> to.

Why is that better than our existing implementation of column statistics?

            regards, tom lane

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