Ühel kenal päeval, L, 2005-12-03 kell 09:21, kirjutas Simon Riggs:
> First off, I think we need to do some more work on partitioning so that
> some knowledge about the union set is understood by the optimizer. At
> the moment there is no concept of partition key, so its hard to spot
> when two union sets have the same key to allow pushdown.
One of the easier cases would be non-overlapping (exclusive) constraints
on union subtables on the joined column.
This could serve as a "partition key", or in case of many nonoverlapping
columns (ex.: table is partitioned by date and region), as many
partition keys.
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Hannu