[Xapian-tickets] [Xapian] #400: Optimise AND_MAYBE when the RHS has a maxweight of 0
Xapian
nobody at xapian.org
Wed Sep 9 14:44:31 BST 2009
#400: Optimise AND_MAYBE when the RHS has a maxweight of 0
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Reporter: richard | Owner: olly
Type: enhancement | Status: new
Priority: normal | Milestone: 1.2.0
Component: Matcher | Version: SVN trunk
Severity: minor | Blockedby:
Platform: All | Blocking:
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If the RHS of an AND_MAYBE clause has an RHS whose maxweight is 0 (or
becomes zero during the search), the AND_MAYBE could be replaced with the
LHS. The attached patch does this. However, it doesn't quite work, due
to two side effects:
- if the AND_MAYBE is part of an OP_SYNONYM, the wdf of the RHS of the
AND_MAYBE can have an effect, but will be lost.
- if a percentage weight calculation is in effect, the count of the
number of terms matching will miss those in the AND_MAYBE.
This doesn't change API at all, so doesn't need to be fixed during the 1.1
series.
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Ticket URL: <http://trac.xapian.org/ticket/400>
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