From: | Peter Eisentraut <peter_e(at)gmx(dot)net> |
---|---|
To: | Andres Freund <andres(at)2ndquadrant(dot)com> |
Cc: | pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: need a function to extract list items from pg_node_tree |
Date: | 2012-12-21 14:01:42 |
Message-ID: | 50D46BC6.1030008@gmx.net |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On 12/21/12 7:26 AM, Andres Freund wrote:
> On 2012-12-21 07:20:00 -0500, Peter Eisentraut wrote:
>> In order to implement the PARAMETER_DEFAULT column in the information
>> schema I need a way to get the expressions out of the proargdefaults
>> column. pg_get_expr(proargdefaults, 0) gives me all expressions
>> comma-separated, but I need them individually. I think a function like
>> pg_get_list_nth (to keep consistent with the internal list API) could
>> work. Alternatively, a list-to-array function might do the trick. Are
>> there are any other potential uses cases that should be considered here?
>> AFAICT, indexprs is the only other system catalog column that contains
>> an expression list.
>
> Hm. Wouldn't it be better to create a pg_node_tree[] and use that in
> pg_attribute? Its already in the variable length part of pg_proc
> anyway...
That sounds like a good idea. I don't know why they are currently
stored as a list.
From | Date | Subject | |
---|---|---|---|
Next Message | Robert Haas | 2012-12-21 14:08:19 | Re: Cascading replication: should we detect/prevent cycles? |
Previous Message | Heikki Linnakangas | 2012-12-21 12:54:02 | Re: pg_basebackup from cascading standby after timeline switch |