On Fri, 23 Jun 2017 09:54:17 -0400 Tom Lane <t...@sss.pgh.pa.us> wrote:
> Yugo Nagata <nag...@sraoss.co.jp> writes: > > When we create a range partitioned table, we cannot use > > a column more than once in the partition key. > > > postgres=# create table t (i int) partition by range(i,i); > > ERROR: column "i" appears more than once in partition key > > AFAIK, that's just a simple test for obvious mistakes; it's not a > property that's essential for correctness. Thanks. This is what I want to know. > > > However, I can use same expression more than once in partition key. > > ... and so, I can't get excited about extending it to expressions. > Where would you stop --- for example, are i and (i) equal? What > about (i) and (case when true then i else j end)? In principle, > the system could recognize both those identities, but it seems > silly to expend code on it just for nagware purposes. > Agreed. > regards, tom lane -- Yugo Nagata <nag...@sraoss.co.jp> -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
