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QE get improved version of full scan (doFullEstimate() and execute())
- To: gcdev <firstname.lastname@example.org>
- Subject: QE get improved version of full scan (doFullEstimate() and execute())
- From: Henrik Nordberg <email@example.com>
- Date: Wed, 10 Feb 1999 19:18:59 -0800
- Organization: Lawrence Berkeley Laboratory, Berkeley, California
Before going to disk to do a full scan over a property, the Query Estimator
now does a bitmap index look-up, and goes to disk only for those events that
lie in the two "side bins" (if any). If a query is exactly on bin boundaries,
there will be no disk access at all.
The changes have been checked into CVS.
Henrik Nordberg <firstname.lastname@example.org>
Scientific Data Management Research Group
Lawrence Berkeley National Laboratory