Re: Exposing quals - Mailing list pgsql-hackers

From Heikki Linnakangas
Subject Re: Exposing quals
Date
Msg-id 4873862F.9040509@enterprisedb.com
Whole thread Raw
In response to Re: Exposing quals  (Simon Riggs <simon@2ndquadrant.com>)
Responses Re: Exposing quals  (David Fetter <david@fetter.org>)
List pgsql-hackers
Simon Riggs wrote:
> SQL, in text form, is the interface to other databases. You can't pass
> half a plan tree to Oracle, especially not a PostgreSQL plan tree. It
> has to be text if you wish to send a query to another RDBMS, or another
> version of PostgreSQL.

Oh, I see. Agreed.

Though note that there's big differences in SQL dialects, so a 
one-size-fits-all approach to generating SQL to be executed in the 
remote database won't work. (not that I think anyone has suggested that)

> So if I understand you, you want to pass the partial plan tree and then
> have a plugin construct the SQL text.

Exactly.

> Maybe you thought I meant internal interfaces should be in text?

Yeah, that's exactly what I thought you meant.

> No,
> that would be bizarre. I meant we should not attempt to pass partial
> plan trees outside of the database, since that would limit the feature
> to only working with the same version of PostgreSQL database. 

Agreed. I'm glad we're on the same page now.

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com


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