Re: TEXT vs PG_NODE_TREE in system columns (cross column and expression statistics patch)

Excerpts from Boszormenyi Zoltan's message of jue abr 28 11:03:56 -0300 2011:
> Hi,
> 
> attached is the WIP patch for cross-column statistics and
> extra expression statistics.
> 
> My question is that why pg_node_tree is unusable as
> syscache attribute? I attempted to alias it as text in the patch
> but I get the following error if I try to use it by setting
> USE_SYSCACHE_FOR_SEARCH to 1 in selfuncs.c.
> Directly using the underlying pg_statistic3 doesn't cause an error.

Two comments:
1. it seems that expression stats are mostly separate from cross-column
stats; does it really make sense to submit the two in the same patch?

2. there are almost no code comments anywhere

3. (bonus) if you're going to copy/paste pg_attribute.h verbatim into
the new files, please remove the bits you currently have in "#if 0".
(Not to mention the fact that the new catalogs seem rather poorly
named).

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Álvaro Herrera <alvherre@commandprompt.com>
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