| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Alvaro Herrera <alvherre(at)commandprompt(dot)com> |
| Cc: | Felix Kater <fkater(at)googlemail(dot)com>, pgsql-general(at)postgresql(dot)org |
| Subject: | Re: unique ID across all columns |
| Date: | 2007-04-17 15:12:56 |
| Message-ID: | 22258.1176822776@sss.pgh.pa.us |
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| Lists: | pgsql-general |
Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> Felix Kater wrote:
>> I need a unique ID across all columns I create. Is it o.k. to
>> achive this by combining pg_attribute.attnum of a column together with
>> the OID of the table the column is in?
> Yes, the table OID is unique, and pg_attribute.attnum is unique as well.
> They are not reused, not even when columns are dropped.
The OID could be re-used after the table is dropped, though. It's not
clear whether Felix needs uniqueness across time or just at any one
instant.
regards, tom lane
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