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Message Posted: Sat, 04 Jun 2005 @ 19:59:14 GMT

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Robert Diehl wrote:

Full ACK.

The word "sample" is missleading, it's not similar to a "select .... sample x".

It's simply scanning the table on each AMP, i.e. the first datablocks per table are read.

Unfortunately a partitioned table is sorted by [partitionnumber, rowid]: If there are 100 partitions a scan of 2% will result in 2 or 3 distinct values and the remaining 97 will be unknown to the optimizer.

I've never seen a warning about that "feature" within the manuals, would be a good candidate for an error message.

Dieter

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