[ http://nagoya.apache.org/jira/browse/XALANJ-1443?page=history ]
Henry Zongaro updated XALANJ-1443:
----------------------------------
Assign To: (was: Xalan Developers Mailing List)
type: Improvement (was: Bug)
Description:
Idea:
Replace expressions in the form of "position() X last()" to the call of
internal optimized function FuncIsLast. This approach improves performance of
such queries and allows to obtain correct results for streaming documents such
as org.apache.xalan.lib.sql.SQLDocument. All these benefits come in expense of
caching just one node per "position() X last()" predicate in the nodeset.
Changes:
All changes are groupped into three attachments: "cvs diff" with current CVS
revision and two new files: FuncIsLast amd DTMIteratorIsLast.
Basic Changes:
1. New interface org.apache.xml.dtm.DTMIteratorIsLast is intended to work with
DTMIterator and responsible for this optimization. It just defines one method:
isLastPos.
2. extended interface org.apache.xpath.axes.SubContextList to include similar
method isLastPos.
3. added internal function org.apache.xpath.functions.FuncIsLast. This function
is created as the result of optimization. It uses DTMIteratorIsLast.isLastPos
and SubContextList.isLastPos methods if available, otherwise, it
performs "position() = last()".
3. Class org.apache.xpath.compiler.Compiler: added code for optimization of
expressions "position() X last()", where X is '=', '!=', '>', '<', '>=', '<='.
Const OPTIMIZE_IS_LAST switches this optimization on/off.
5. Classes in the org.apache.xpath.axes package: implemented next-node-prefetch
system for is-last optimization.
Testing:
Obtained code has been tested against existing conf-gold tests. No problems
have been discovered. Results of testing will be posted as an additional
attachement.
Peformance:
Performance testing was executed. Results will be posted as an additional
comments.
was:
Idea:
Replace expressions in the form of "position() X last()" to the call of
internal optimized function FuncIsLast. This approach improves performance of
such queries and allows to obtain correct results for streaming documents such
as org.apache.xalan.lib.sql.SQLDocument. All these benefits come in expense of
caching just one node per "position() X last()" predicate in the nodeset.
Changes:
All changes are groupped into three attachments: "cvs diff" with current CVS
revision and two new files: FuncIsLast amd DTMIteratorIsLast.
Basic Changes:
1. New interface org.apache.xml.dtm.DTMIteratorIsLast is intended to work with
DTMIterator and responsible for this optimization. It just defines one method:
isLastPos.
2. extended interface org.apache.xpath.axes.SubContextList to include similar
method isLastPos.
3. added internal function org.apache.xpath.functions.FuncIsLast. This function
is created as the result of optimization. It uses DTMIteratorIsLast.isLastPos
and SubContextList.isLastPos methods if available, otherwise, it
performs "position() = last()".
3. Class org.apache.xpath.compiler.Compiler: added code for optimization of
expressions "position() X last()", where X is '=', '!=', '>', '<', '>=', '<='.
Const OPTIMIZE_IS_LAST switches this optimization on/off.
5. Classes in the org.apache.xpath.axes package: implemented next-node-prefetch
system for is-last optimization.
Testing:
Obtained code has been tested against existing conf-gold tests. No problems
have been discovered. Results of testing will be posted as an additional
attachement.
Peformance:
Performance testing was executed. Results will be posted as an additional
comments.
Environment:
Operating System: Other
Platform: Other
was:
Operating System: Other
Platform: Other
Priority: Major
Bugzilla Id: (was: 17941)
> position() = last() optimization
> --------------------------------
>
> Key: XALANJ-1443
> URL: http://nagoya.apache.org/jira/browse/XALANJ-1443
> Project: XalanJ2
> Type: Improvement
> Components: XPath
> Versions: CurrentCVS
> Environment: Operating System: Other
> Platform: Other
> Reporter: Dimitry E Voytenko
> Attachments: diff.txt, islast-test-20030305.zip,
> org.apache.xml.dtm.DTMIteratorIsLast.java,
> org.apache.xpath.functions.FuncIsLast.java
>
> Idea:
> Replace expressions in the form of "position() X last()" to the call of
> internal optimized function FuncIsLast. This approach improves performance of
> such queries and allows to obtain correct results for streaming documents
> such
> as org.apache.xalan.lib.sql.SQLDocument. All these benefits come in expense
> of
> caching just one node per "position() X last()" predicate in the nodeset.
> Changes:
> All changes are groupped into three attachments: "cvs diff" with current CVS
> revision and two new files: FuncIsLast amd DTMIteratorIsLast.
> Basic Changes:
> 1. New interface org.apache.xml.dtm.DTMIteratorIsLast is intended to work
> with
> DTMIterator and responsible for this optimization. It just defines one
> method:
> isLastPos.
> 2. extended interface org.apache.xpath.axes.SubContextList to include similar
> method isLastPos.
> 3. added internal function org.apache.xpath.functions.FuncIsLast. This
> function
> is created as the result of optimization. It uses DTMIteratorIsLast.isLastPos
> and SubContextList.isLastPos methods if available, otherwise, it
> performs "position() = last()".
> 3. Class org.apache.xpath.compiler.Compiler: added code for optimization of
> expressions "position() X last()", where X is '=', '!=', '>', '<', '>=',
> '<='.
> Const OPTIMIZE_IS_LAST switches this optimization on/off.
> 5. Classes in the org.apache.xpath.axes package: implemented
> next-node-prefetch
> system for is-last optimization.
> Testing:
> Obtained code has been tested against existing conf-gold tests. No problems
> have been discovered. Results of testing will be posted as an additional
> attachement.
> Peformance:
> Performance testing was executed. Results will be posted as an additional
> comments.
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