Class Options

Configures Global Static Options for the Library.

Inheritance
object
Options
Inherited Members
Namespace: VDS.RDF
Assembly: dotNetRdf.dll
Syntax
public static class Options
Remarks

Some of these are Debug Build only, please see the Remarks on individual members for more detail.

Properties

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AlgebraOptimisation

Gets/Sets whether Algebra Optimisation should be used.

Declaration
[Obsolete("This API will be removed in a future release. Algebra optimisation can be set in the options callback when creating a new LeviathanQueryProcessor.")]
public static bool AlgebraOptimisation { get; set; }
Property Value
Type Description
bool
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AllowMultiThreadedWriting

Gets/Sets whether multi-theaded writing is permitted.

Declaration
[Obsolete("This API has been deprecated. Writers that support multi-threaded writing now provide a property and a constructor parameter to control the use of this feature.")]
public static bool AllowMultiThreadedWriting { get; set; }
Property Value
Type Description
bool
Remarks

In some contexts multi-threaded writing may not even work due to restrictions on thread types since we use the System.Threading.WaitAll method which is only valid in MTA contexts.

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DefaultComparisonOptions

Gets/Sets the default collation for literal comparison when literals are string or not implicitely comparable (different types, parse/cast error...)

Declaration
[Obsolete("This API has been deprecated and will be removed in a future release. Please refer to the changelog for details on the replacement for this API.")]
public static CompareOptions DefaultComparisonOptions { get; set; }
Property Value
Type Description
CompareOptions
Remarks

The default is set to Ordinal to preserve behavioural backwards compatibility with past versions of dotNetRDF.

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DefaultCompressionLevel

Gets/Sets the Default Compression Level used for Writers returned by the MimeTypesHelper class when the writers implement ICompressingWriter.

Declaration
[Obsolete("This API will be removed in a future release. The compression level for a writer can be set using the CompressionLevel property of the writer.")]
public static int DefaultCompressionLevel { get; set; }
Property Value
Type Description
int
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DefaultCulture

Gets/Sets the default culture literal comparison when literals are string or not implicitely comparable (different types, parse/cast error...)

Declaration
[Obsolete("This API has been deprecated and will be removed in a future release. Please refer to the changelog for details on the replacement for this API.")]
public static CultureInfo DefaultCulture { get; set; }
Property Value
Type Description
CultureInfo
Remarks

The default is set to the invariant culture to preserve behavioural backwards compatibility with past versions of dotNetRDF.

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DefaultTokenQueueMode

Gets/Sets the default token queue mode used for tokeniser based parsers.

Declaration
[Obsolete("This API has been deprecated. Use the ITokenisingParser.TokenQueueMode property instead, or pass the desired TokenQueueMode to the constructor of those parsers that support this option.")]
public static TokenQueueMode DefaultTokenQueueMode { get; set; }
Property Value
Type Description
TokenQueueMode
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ForceBlockingIO

Gets/Sets whether Blocking IO should be forced.

Declaration
[Obsolete("This API has been deprecated. Setting this option will not change the use of blocking IO for streams. Please refer to the change notes for this release for a workaround.", true)]
public static bool ForceBlockingIO { get; set; }
Property Value
Type Description
bool
Remarks

Blocking IO refers to how the parsing sub-system reads in inputs, it will use Blocking/Non-Blocking IO depending on the input source. In most cases the detection of which to use should never cause an issue but theoretically in some rare cases using non-blocking IO may lead to incorrect parsing errors being thrown (premature end of input detected), if you suspect this is the case try enabling this setting. If you still experience this problem with this setting enabled then there is some other issue with your input.

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ForceHttpBasicAuth

Gets/Sets whether Basic HTTP authentication should be forced.

Declaration
[Obsolete("This API has been deprecated. There is currently no replacement for this API.", true)]
public static bool ForceHttpBasicAuth { get; set; }
Property Value
Type Description
bool
Remarks

There have been reported problems where some servers don't cope nicely with the HTTP authentication challenge response procedure resulting in failed HTTP requests. If the server only uses Basic HTTP authentication then you can opt to force dotNetRDF to always include the HTTP basic authentication header in requests and thus workaround this problem.

Warning: Under Silverlight this will only work correctly if usernames and passwords are composed only of characters within the ASCII range.

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FullTripleIndexing

Controls whether the indexed triple collections will create full indexes for the Triples inserted into it.

Declaration
[Obsolete("This API will be removed in a future release. Classes that create an in-memory index of triples now provide a constructor parameter to control the use of full triple indexing.")]
public static bool FullTripleIndexing { get; set; }
Property Value
Type Description
bool
Remarks

By default indexes triple collections creates indexes on Triples based upon Subjects, Predicates and Objects alone. When full indexing is enabled it also creates indexes based on Subject-Predicate, Predicate-Object and Subject-Object pairs which may improve query speed but will use additional memory.

Default setting for Full Indexing is enabled, enabling/disabling it only has an effect on indexed triple collection instances instantiated after full indexing was enabled/disabled i.e. existing Graphs in memory using the indexed triple collections continue to use the full indexing setting that was present when they were instantiated.

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HttpDebugging

Gets/Sets whether HTTP Request and Response Information should be output to the Console Standard Out for Debugging purposes.

Declaration
[Obsolete("This API has been deprecated. Please use the standard .NET HttpClient logging facility instead", true)]
public static bool HttpDebugging { get; set; }
Property Value
Type Description
bool
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HttpFullDebugging

Gets/Sets whether the HTTP Response Stream should be output to the Console Standard Output for Debugging purposes.

Declaration
[Obsolete("This API has been deprecated. Please use the standard .NET HttpClient logging facility instead", true)]
public static bool HttpFullDebugging { get; set; }
Property Value
Type Description
bool
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InternUris

Gets/Sets whether the library will attempt to intern URIs to reduce memory usage.

Declaration
[Obsolete("This API has been deprecated. Use UriFactory.InternUris instead.")]
public static bool InternUris { get; set; }
Property Value
Type Description
bool
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LiteralEqualityMode

Gets/Sets the Mode used to compute Literal Equality (Default is Strict which enforces the W3C RDF Specification).

Declaration
[Obsolete("This API will be removed in a future release. Use EqualityHelper.LiteralEqualityMode instead.")]
public static LiteralEqualityMode LiteralEqualityMode { get; set; }
Property Value
Type Description
LiteralEqualityMode
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LiteralValueNormalization

Gets/Sets whether Literal Values should be normalized.

Declaration
[Obsolete("This API will be removed in a future release. Use INodeFactory.NormalizeLiteralValues instead.")]
public static bool LiteralValueNormalization { get; set; }
Property Value
Type Description
bool
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QueryAllowUnknownFunctions

Gets/Sets whether functions that can't be parsed into Expressions should be represented by the UnknownFunction.

Declaration
[Obsolete("This API will be removed in a future release. The option can be set as an option on the SparqlQueryParser or SparqlUpdateParser class")]
public static bool QueryAllowUnknownFunctions { get; set; }
Property Value
Type Description
bool
Remarks

When set to false a Parser Error will be thrown if the Function cannot be parsed into an Expression.

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QueryExecutionTimeout

Gets/Sets the Hard Timeout limit for SPARQL Query Execution (in milliseconds).

Declaration
[Obsolete("This API will be removed in a future release. Timeout can be set in the options callback when creating a new LeviathanQueryProcessor.")]
public static long QueryExecutionTimeout { get; set; }
Property Value
Type Description
long
Remarks

This is used to stop SPARQL queries running away and never completing execution, it defaults to 3 mins (180,000 milliseconds).

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QueryOptimisation

Gets/Sets whether Query Optimisation should be used.

Declaration
[Obsolete("This API will be removed in a future release. Query optimisation can be set when creating a new SparqlQueryParser or SparqlUpdateParser.")]
public static bool QueryOptimisation { get; set; }
Property Value
Type Description
bool
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RigorousEvaluation

Gets/Sets whether to use rigorous query evaluation.

Declaration
[Obsolete("This API will be removed in a future release. This option can be set in the options callback on the LeviathanQueryProcessor class.")]
public static bool RigorousEvaluation { get; set; }
Property Value
Type Description
bool
Remarks

Rigorous Query evaluation applies more checks to the triples produced by datasets to ensure they actually match the patterns being scanned. If the underlying index structures are able to guarantee this then rigorous evaluation may be turned off for faster evaluation which it is by default since our default TreeIndexedTripleCollection and TripleCollection implementations will guarantee this.

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StrictOperators

Gets/Sets whether to use strict operators.

Declaration
[Obsolete("This API will be removed in a future release. This option can be set in the options callback on the LeviathanQueryProcessor class.")]
public static bool StrictOperators { get; set; }
Property Value
Type Description
bool
Remarks

Strict Operators refers to the interpretation of certian operators like + and - in SPARQL expression evaluation. If enabled then the operators will function only as specified in the SPARQL specification, if disabled (which is the default) then certain extensions (which the SPARQL specification allows an implementation to provide) will be allowed e.g. date time arithmetic.

The only time you may want to disable this is if you are developing queries locally which you want to ensure are portable to other systems or when running the SPARQL compliance tests.

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UnsafeOptimisation

Gets/Sets whether some Optimisations considered unsafe can be used.

Declaration
[Obsolete("This API will be removed in a future release. Unsafe optimisation can be enabled by setting the UnsafeOptimisation property on those IAlgebraOptimiser classes that support it. Changing this static property at runtime will not alter algebra optimisation behaviour.", true)]
public static bool UnsafeOptimisation { get; set; }
Property Value
Type Description
bool
Remarks

The notion of unsafe optimisations refers to optimisations that can make significant performance improvements to some types of queries but are disabled normally because they may lead to behaviour which does not strictly align with the SPARQL specification.

One example of such an optimisation is an implicit join where the optimiser cannot be sure that the variables involved don't represent literals.

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UpdateExecutionTimeout

Gets/Sets the Hard Timeout limit for SPARQL Update Execution (in milliseconds).

Declaration
[Obsolete("This API will be removed in a future release. This option can be set in the options callback on the LeviathanUpdateProcessor class.")]
public static long UpdateExecutionTimeout { get; set; }
Property Value
Type Description
long
Remarks

This is used to stop SPARQL Updates running away and never completing execution, it defaults to 3 mins (180,000 milliseconds).

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UriLoaderCaching

Gets/Sets whether the UriLoader uses caching.

Declaration
[Obsolete("This API will be removed in a future release. Use UriLoader.CacheEnabled instead")]
public static bool UriLoaderCaching { get; set; }
Property Value
Type Description
bool
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UriLoaderTimeout

Gets/Sets the Timeout for URI Loader requests (Defaults to 15 seconds).

Declaration
[Obsolete("This API will be removed in a future release. Use UriLoader.Timeout instead")]
public static int UriLoaderTimeout { get; set; }
Property Value
Type Description
int
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UseBomForUtf8

Gets/Sets whether a UTF-8 BOM is used for UTF-8 Streams created by dotNetRDF (this does not affect Streams passed directly to methods as open streams cannot have their encoding changed).

Declaration
[Obsolete("This API has been deprecated. To control the use of UTF-8 BOM, set the appropriate text encoding in the writer constructor.")]
public static bool UseBomForUtf8 { get; set; }
Property Value
Type Description
bool
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UseDtd

Gets/Sets whether a DTD should be used for some XML formats to compress output.

Declaration
[Obsolete("This API has been deprecated. Writers that support the use of an XML DTD now provide a property and a constructor parameter to control the use of a DTD when writing.")]
public static bool UseDtd { get; set; }
Property Value
Type Description
bool
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UsePLinqEvaluation

Gets/Sets whether the query engine will try to use PLinq where applicable to evaluate suitable SPARQL constructs in parallel.

Declaration
[Obsolete("This API will be removed in a future release. This option can be set in the options callback on the LeviathanQueryProcessor class.")]
public static bool UsePLinqEvaluation { get; set; }
Property Value
Type Description
bool
Remarks

For the 0.6.1 release onwards this was an experimental feature and disabled by default, from 0.7.0 onwards this is enabled by default.

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ValidateIris

Gets/Sets whether IRIs are validated by parsers which support this functionality.

Declaration
[Obsolete("This API has been deprecated. This option to force validation of parsed IRIs was only used in the Turtle parsers and can now be specified in the constructor of those parsers.")]
public static bool ValidateIris { get; set; }
Property Value
Type Description
bool
Remarks

When enabled certain parsers will validate all IRIs they see to ensure that they are valid and throw a parser error if they are not. Since there is a performance penalty associated with this and many older RDF standards were written pre-IRIs (thus enforcing IRI validity would reject data considered valid by those specifications) this feature is disabled by default.