Re: Rule recompilation

Alex Pilosov wrote:
> I remember awhile ago, someone floated the idea of a dependency view which
> would list all objects and what OIDs they have in their plan. (i.e. what
> do they depend on).
>
> I'm definitely no expert in this, but to me, one possible implementation
> would be to enhance outfuncs to provide for creation tracking of all
> OIDs used in plan, and allow caller to receive this list and do something
> with it. This would actually be very simple, as only _outOidList will need
> to be modified...(but then again, I'm known for oversimplifying things :)
>
> Then, we can add  ev_depends/oidvector to pg_rewrite and store the
> dependency there, and for stored procedures, add a prodepends/oidvector to
> pg_proc.
>
> Then, create union of pg_rewrite and pg_proc to list dependencies.
>
> Then, we would be able to provide warning when an object is dropped:
> 'The following objects depend on this blah blah', and possibly an action
> "alter database fixdepends oid" which would recompile everything that
> depends on that oid.
>
> How's this sound?
   Er - oversimplified :-)
   I  remember  it well, because Bruce is mentioning it every so   often and constantly tries to convince me to start a
project   about a dependency table.  I just think it's better not to do   it for 7.2 (didn't we  wanted  to  have  that
released  THIS   year?).
 
   Anyway,  there's  alot  more  to  look  at.  Functions can be   referenced in views, indexes, operators, aggregates
andmaybe   more  places.  Views/rules  can reference allmost any object.   And this only builds the permanent cross
reference.
   We have to take a look at runtime information, telling  which   prepared/saved  SPI plan uses a particular object
andtrigger   automatic re-prepare for the plan in case.
 
   For most objects, there is no such "recompile" possible -  at   least  not  without  storing  alot more information
thannow.   Create a function and based on that  an  operator.  Then  you   drop  the  function and create another one.
Hmmm,pg_operator   doesn't have the function name and argument  types,  it  only   knows the old functions oid. How do
youfind the new function   from here? So  basically  we'd  need  some  sort  of  pg_dump   snippet  associated  with
everyobject and issue an internal   DROP/CREATE using that string to recompile it.
 


Jan

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