GraphDB-SE Configuration

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Version 7 by reneta.popova
on Aug 26, 2014 12:30.

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| *enablePredicateList* | X | X | Yes \\ | _default_ *false:* enables or disables mappings from an entity (subject or object) to its predicates; switching this on can drastically speed up queries that use wildcard predicate patterns. |
| *entity-id-size* | X | X | No \\ | _default_ *32*, possible values are *32* and *40*; defines the bit size of internal IDs used to index entities (URIs, blank nodes and literals). For most cases, this parameter can be left to its default value. However, if very large datasets are used that contain more than 2{^}32^ entities, then this parameter should be set to *40*. Be aware, that this can only be set when instantiating a new repository and converting an existing repository between 32 and 40-bit entity widths is not possible. |
| *entity-index-size* | X | X | No \\ | _default_ *1000000*, defines the number of entity hash table index entries; the bigger the size, the less the collisions in the hash table and the faster the entity retrieval; the entity hash table does not rehash, so its index size is constant throughout the life of the repository. |
| *ftsIndexPolicy* | X | X | Yes \\ | _default_ *never*, possible values are *onCommit*, *onStartup*, *onShutdown*, *never*; turns on and off the default mechanism for full text search used via the built-in predicates described in section 10.1; section 10.1; if _FTS_ is turned on then, depending on the value, it determines when the indexing will take place: *onCommit* \- at the end of each transaction, *onStartup* -- at initialisation, *onShutdown* \- on repository shutdown. |
| *ftsLiteralsOnly* | X | X | Yes \\ | _default_ *false*, if the Node search (full-text search) mechanism is enabled, this parameter specifies whether only literals will be indexed (value of *true*, enough in 90% of the cases) or everything (value of *false*). |
| *fts-memory* | X | X | Yes \\ | _default_ *20m*, specifies the amount of memory to be used for the _FTS_ index cache. |
*file-repository* \\
*weighted-file-repository* |
| *ruleset* | X | X | {color:#ff0000}Must NOT change{color}\\ | _default_ *owl-horst-optimized*, built-in rule sets are *empty*, *rdfs*, *owl-horst*, *owl-max* and *owl2-rl* and their optimizsed counterparts *rdfs-optimized*, *owl-horst-optimized*, *owl-max-optimized* and *owl2-rl-optimized*. A custom rule set is chosen by setting the path to its rule file (.pie). |
| *storage-folder* | X | X | Yes \\ | _default_ *none*, specifies the folder where the index files will be stored. |
| *throw-QueryEvaluationException-on-timeout* | X | X | Yes \\ | _default_ *false*, if set to true, then a QueryEvaluationException is thrown when the duration of a query execution exceeds the time-out parameter. |
| *tokenization-regex* | X | X | Yes \\ | _default_ *\[\p\{L\}\d_\]\+*, defines the rule for splitting strings into tokens; the tokens themselves, not the strings, are stored in the _FTS_ index, so it is important to define a suitable tokenization for the given application (e.g. in some cases intensive number parsing is used, in other cases - personal names, i.e. ones starting with capital letter and may contain hyphens and apostrophes, etc.) |
| *transaction-mode* | X | X | Yes \\ | _default_ *safe*, specifies the transaction mode. In *fast* mode, dirty pages are written to disk in the most lazy fashion possible, i.e. pages are only swapped when a new page is requested and there is no more memory available. No guarantees about data security are given when operating in this mode, so that in the event of an abnormal termination, the database must be considered corrupted and will need to be recreated from scratch. \\
When set to *safe*, all updates are flushed to disk at the end of each transaction. Commit operations will normally takes a little longer, but recovery after an abnormal termination is instant. This mode also has much better concurrency characteristics. |
| *transaction-isolation* | X | X | Yes \\ | _default_ *true*, this parameter only has an effect when {{transaction-mode=fast}}. In fast mode, updates will lock the repository preventing concurrent query answering. However, if this parameter is set to false, concurrent queries are permitted with the loss of isolation. |
| *tuple-index-memory* | X | X | Yes \\ | _default_ *80m*, specifies the amount of memory to be used for statement storage cache. |
| *useShutdownHooks* | | X | Yes \\ | _default_ *true*, if _true_ then the method *OwlimSchemaRepository.shutdown()* is called when the Java Virtual Machine (JVM) exits (running GraphDB under Tomcat requires this parameter to be *true*, otherwise it cannot be guaranteed that the *shutdown()* method will be called at all). |