Announcing OWLIM 5.4 - a number of resilience improvements, Sesame 2.7.7

Ontotext are pleased to announce the release of OWLIM version 5.4 that includes Sesame 2.7.7 and a number of resilience improvements in OWLIM-SE and OWLIM-Enterprise. This version is compatible with any OWLIM database created with OWLIM since version 5.0.

The focus of this release is on stability, SPARQL compliance and performance improvements. In particular the following are worth mentioning:

Fixed delete performance degradation after several iterations of deleting large amounts of triples
Workbench "Explore" function now works for stores with large amounts of data
Fixes in the full-text search (FTS/Lucene) plug-in indexing configurations, related to parameters luc:excludePredicates, luc:includePredicates and deeper molecule sizes (moleculeSize > "2")
The OWLIM Enterprise Cluster should be more responsive under huge load; there is a new dedicated HTTPClient connection reserved for system requests (Master Node - Worker Nodes communication) and those system requests do not interfere with the other user query requests. Also write queries are executed across the cluster in two steps only (instead of three steps).

Sesame 2.7 has some significant differences in regard to transaction management. Transactions are now started with a call to begin() rather than implicitly when an update operation is started. If begin() is not used, then the behaviour reverts to what was previously called 'auto-commit', i.e. any update operation is committed immediately. HTTPRepository now supports background parsing/concurrent reading of results. For full details, please see the Sesame notes here. The bundled Sesame release (2.7.7) includes also correct handling of SPARQL "IN" operator and a number of parsing fixes and improvements in comparison to plain 2.7.

The bundled Apache Lucene library was updated to version 3.6.2 in preparation for a new statement-oriented full-text search plug-in that will be published in the near future. Several extensions have been made to OWLIM's plug-in API to support this, as well as to allow closer integration with some GATE-based text analytics components licensed separately from Ontotext.

Version 5.4 of OWLIM is available now. For a full list of updates, see the release notes for the relevant edition of OWLIM.



The OWLIM team
October 2013