On 2013-10-23 21:20:58 +0100, Dean Rasheed wrote:
> On 23 October 2013 21:08, Andres Freund <andres@2ndquadrant.com> wrote:
> > On 2013-10-23 20:51:27 +0100, Dean Rasheed wrote:
> >> Hmm, my first thought is that rewriteTargetView() should be calling
> >> AcquireRewriteLocks() on viewquery, before doing too much with it.
> >> There may be sub-queries in viewquery's quals (and also now in its
> >> targetlist) and I don't think the relations referred to by those
> >> sub-queries are getting locked.
> >
> > Well, that wouldn't follow the currently documented rule ontop
> > of QueryRewrite:
> > * NOTE: the parsetree must either have come straight from the parser,
> > * or have been scanned by AcquireRewriteLocks to acquire suitable locks.
> >
> > It might still be the right thing to do, but it seems suspicious that
> > the rules need to be tweaked like that.
> >
>
> Well it matches what already happens in other places in the rewriter
> --- see rewriteRuleAction() and ApplyRetrieveRule(). It's precisely
> because the rule action's query hasn't come from the parser that it
> needs to be processed in this way.
I really don't know that are of code that well, fortunately I never had
to wade around it much so far...
Reading your explanation and a bit of the code your plan sound sane. Are
you going to propose a patch?
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services
