|From:||Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>|
|To:||Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>|
|Cc:||Craig Ringer <craig(at)2ndquadrant(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>|
|Subject:||Re: patch: function xmltable|
|Views:||Raw Message | Whole Thread | Download mbox|
2016-12-04 23:00 GMT+01:00 Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>:
> 2016-12-03 16:03 GMT+01:00 Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>:
>> Pavel Stehule wrote:
>> > 2016-12-02 23:25 GMT+01:00 Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>:
>> > > This is looking much better now, but it still needs at least the
>> > > following changes.
>> > >
>> > > First, we need to fix is the per_rowset_memcxt thingy. I think the
>> > > it's currently being used is rather ugly; it looks to me like the
>> > > context does not belong into the XmlTableContext struct at all.
>> > > Instead, the executor code should keep the memcxt pointer in a state
>> > > struct of its own, and it should be the executor's responsibility to
>> > > change to the appropriate context before calling the table builder
>> > > functions. In particular, this means that the table context can no
>> > > longer be a void * pointer; it needs to be a struct that's defined by
>> > > the executor (probably a primnodes.h one). The void * pointer is
>> > > stashed inside that struct. Also, the "routine" pointer should not be
>> > > part of the void * struct, but of the executor's struct. So the
>> > > execQual code can switch to the memory context, and destroy it
>> > > appropriately.
>> > >
>> > > Second, we should make gram.y set a new "function type" value in the
>> > > TableExpr it creates, so that the downstream code (transformTableExpr,
>> > > ExecInitExpr, ruleutils.c) really knows that the given function is
>> > > XmlTableExpr, instead of guessing just because it's the only
>> > > case. Probably this "function type" is an enum (currently with a
>> > > value TableExprTypeXml or something like that) in primnodes.
>> > It has sense - I was not sure about it - because currently it is only
>> > value, you mentioned it.
>> True. This is a minor point.
>> Are you able to do the memory context change I describe?
> I am not sure if I understand well to your ideas - please, check attached
attached patch without your patch 0001
>> Álvaro Herrera https://www.2ndQuadrant.com/
>> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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