On Sat, Dec 6, 2014 at 3:06 AM, Amit Kapila <amit.kapil...@gmail.com> wrote: > Sure, I don't feel we should not provide anyway to take dump > for individual partition but not at level of independent table. > May be something like --table <table_name> > --partition <partition_name>. > > In general, I think we should try to avoid exposing that partitions are > individual tables as that might hinder any future enhancement in that > area (example if we someone finds a different and better way to > arrange the partition data, then due to the currently exposed syntax, > we might feel blocked).
I guess I'm in disagreement with you - and, perhaps - the majority on this point. I think that ship has already sailed: partitions ARE tables. We can try to make it less necessary for users to ever look at those tables as separate objects, and I think that's a good idea. But trying to go from a system where partitions are tables, which is what we have today, to a system where they are not seems like a bad idea to me. If we make a major break from how things work today, we're going to end up having to reimplement stuff that already works. Besides, I haven't really seen anyone propose something that sounds like a credible alternative. If we could make partition objects things that the storage layer needs to know about but the query planner doesn't need to understand, that'd be maybe worth considering. But I don't see any way that that's remotely feasible. There are lots of places that we assume that a heap consists of blocks number 0 up through N: CTID pointers, index-to-heap pointers, nodeSeqScan, bits and pieces of the way index vacuuming is handled, which in turn bleeds into Hot Standby. You can't just decide that now block numbers are going to be replaced by some more complex structure, or even that they're now going to be nonlinear, without breaking a huge amount of stuff. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
