Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> Excerpts from Boszormenyi Zoltan's message of jue abr 28 11:03:56 -0300 2011:
>> ERROR:  could not determine which collation to use for string comparison
>> HINT:  Use the COLLATE clause to set the collation explicitly.

> Maybe the pg_node_tree problem is a bug with the collation feature.  If
> you could reproduce it in unpatched master, I'm sure it'd find a quick
> death.

Actually, I rather imagine it comes from this choice in catcache.c:

        /* Currently, there are no catcaches on collation-aware data types */
        cache->cc_skey[i].sk_collation = InvalidOid;

I'd be more worried about that if I thought it made any sense to use
a pg_node_tree column as an index key, but I don't ...

			regards, tom lane

In response to

• Re: TEXT vs PG_NODE_TREE in system columns (cross column and expression statistics patch) at 2011-04-28 15:21:39 from Alvaro Herrera

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