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I've always been a fan of PostgreSQL. The one bit that appealed to me was its erstwhile ability to 'shard', or partition data across tables. http://enfranchis

• lneves 19y ago
  If you haven't seen it yet, check this presentation about partitioning with PostgreSQL: http://images.omniti.net/omniti.com/talks/partitions-public.pdf http://images.omniti.net/omniti.com/talks/partitions-public....
• bayareaguy 19y ago
  Unfortunately the current PostgreSQL optimizer/executor doesn't do as much as it could when joining records from subtables partitioned with inherits clauses. If you have a query with a predicate that can be pushed down to a subtable index then you're probably ok. However if you are doing something more intensive like an unqualified aggregation then you'll be in for a disappointment since the executor doesn't know how to preserve ordering when it scans the subtables. It will always give you a hash join or a merge join involving an intermediate sort even when the sort could be avoided by using an index scan of the subtables with something like a priority queue. This can be worked around by doing your own incremental aggregations over the subtables and combining them, but it's a little bit of a pain.