On Dec 1, 2010, at 8:59 AM, Andrew Dunstan wrote:
> On 12/01/2010 09:41 AM, Tom Lane wrote:
>> ghatpande@vsnl.net writes:
>>> Create domain is only useful for abstracting common constraints on fields into single location for maintenance. It
maynot be useful to link tables.
>> It's still unclear what this does that you don't get from inheritance,
>> typed tables, use of a table's rowtype as a field type, or CREATE TABLE
>> LIKE. This isn't exactly virgin territory.
>>
>>
>
> Yeah. Actually, the whole thing reminded me somewhat of the pre-RDBMS data stores I worked with 25 years or so ago.
"Thosewho cannot remember history are doomed to repeat it."
Something that did what Pavel mentioned:
SELECT name, parent->name FROM children;
would be very useful. It means you no longer have to write explicit joins (or perhaps more accurately, you no longer
haveto specify exactly how to join the two tables).
--
Jim C. Nasby, Database Architect jim@nasby.net
512.569.9461 (cell) http://jim.nasby.net