Re: WIP: hooking parser - Mailing list pgsql-hackers

From Pavel Stehule
Subject Re: WIP: hooking parser
Date
Msg-id [email protected]
Whole thread Raw
In response to Re: WIP: hooking parser  (Heikki Linnakangas <[email protected]>)
List pgsql-hackers
2009/2/13 Heikki Linnakangas <[email protected]>:
> Peter Eisentraut wrote:
>>
>> Tom Lane wrote:
>>>
>>> Peter Eisentraut <[email protected]> writes:
>>>>
>>>> I think what you want here is some way to define a function that takes
>>>> an arbitrary number of arguments of arbitrary type and let the function
>>>> figure everything out.  I see no reason why this can't be a variant on
>>>> CREATE FUNCTION, except that of course you need to figure out some API and
>>>> function resolution details.
>>>
>>> We've already got "variadic any" functions --- the problem is to tell
>>> the parser what the function's result type will be, given a particular
>>> parameter list.  I agree that hooking transformExpr is not exactly the
>>> most ideal way to attack that from a performance or complexity
>>> standpoint.
>>
>> What is the defined return type logic for the decode() function anyway?
>>  If you want the full CASE-like resolution logic, it might be very hard to
>> fit that into a general system.
>
> And on top of that, decode() is supposed to do short-circuit evaluation of
> the arguments.
>

yes, you should to look so this work do transform hook very vell

regards
Pavel


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


pgsql-hackers by date:

Previous
From: Peter Eisentraut
Date:
Subject: Re: per-database locale: createdb switches
Next
From: Peter Eisentraut
Date:
Subject: Re: WIP: hooking parser