Help:Con­figu­ration para­meter "$smwgQFilterDuplicates"

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Title $smwgQFilterDuplicates
Description Sets whether duplicate query conditions should be removed from computing query results
Default setting
false
(Other) available settings
true

Allows to remove duplicate query conditions from computing query results

Software Semantic MediaWiki
First version supported
Last version supported still available
Configuration Query settings · Inline queries · Experimental
Keyword inline queries · queries · query performance · performance · experimental

$smwgQFilterDuplicates is a configuration parameter that sets whether duplicate query conditions (segments) should be removed from computing query results. Thus the computational effort for conditions (segments) that represent that same query signature is being eliminated. The impact of this optimization is currently unknown. The configuration parameter was introduced in Semantic MediaWiki 2.5.0Released on 14 March 2017 and compatible with MW 1.23.0 - 1.29.x..1

The idea behind this configuration parameter is to filter some query segments (the part that represents individual SQL statements of a query, i.e. query conditions) that can be duplicate and would create an additional temp table which in return would lengthen the time the SQL engine needs to answer the query. If enabled Semantic MediaWiki tries to match the fingerprint of a description and replaces the reference if matched before the "QueryEngine" becomes aware of the segments.

Using the feature connected to this configuration parameter is currently considered being experimental!

Default setting

$smwgQFilterDuplicates = false;

This means that duplicate query segments are not being removed from computing query results.

Changing the default setting

To modify this configuration setting, add one of the following lines to your "LocalSettings.php" file after the enableSemantics() call:

Enable duplicate query conditions being removed from computing query results
$smwgQFilterDuplicates = true;

This means that duplicate query segments are being removed from computing query results.

See also

References

  1. ^  Semantic MediaWiki: GitHub pull request gh:smw:2176