Dean Rasheed <dean.a.rash...@googlemail.com> writes: > 2010/1/9 Tom Lane <t...@sss.pgh.pa.us>: >> Dean Rasheed <dean.a.rash...@googlemail.com> writes: >>> I wonder if it might be better to have plpgsql_parse_dblword() ignore >>> plpgsql_LookupIdentifiers, and always do the lookups.
>> Not if you'd like things to still work. > OK, I admit that I'm totally new that area of code, so I'm not seeing > it - what does it break? The main problem is it will throw errors in some cases where that's premature. For instance we might have a.x where a is a plpgsql row variable that doesn't contain x ... but if the reference is in a query where a is a table that contains x, and we are using prefer-the-column rules, this is not an error case. Also we do not want any lookups while looking at DECLARE constructs --- it doesn't matter whether there's an outer-scope variable of the same name. However, it turns out my solution isn't working too well either :-(. I can make it work for some of the system columns, but not for xmin, xmax, or cmin/cmax because those fields of a regular tuple are overlaid with datum-tuple header fields. So by the time ExecEvalFieldSelect gets the tuple those values are irretrievably trashed. I think that a variant of your idea could be made to work: change plpgsql_LookupIdentifiers to a three-state variable (which'd basically mean "in DECLARE, in a SQL expression, anywhere else"), do no lookups in DECLARE, and in SQL expressions do lookups but never throw any errors. I'll have a go at that. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers