> From: Robert Haas [mailto:robertmh...@gmail.com] > On Sat, Dec 6, 2014 at 2:59 AM, Amit Kapila <amit.kapil...@gmail.com> > wrote: > >> I guess you could list or hash partition on multiple columns, too. > > > > How would you distinguish values in list partition for multiple > > columns? I mean for range partition, we are sure there will > > be either one value for each column, but for list it could > > be multiple and not fixed for each partition, so I think it will not > > be easy to support the multicolumn partition key for list > > partitions. > > I don't understand. If you want to range partition on columns (a, b), > you say that, say, tuples with (a, b) values less than (100, 200) go > here and the rest go elsewhere. For list partitioning, you say that, > say, tuples with (a, b) values of EXACTLY (100, 200) go here and the > rest go elsewhere. I'm not sure how useful that is but it's not > illogical. >
In case of list partitioning, 100 and 200 would respectively be one of the values in lists of allowed values for a and b. I thought his concern is whether this "list of values for each column in partkey" is as convenient to store and manipulate as range partvalues. Thanks, Amit -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
