Class Options

Configures Global Static Options for the Library.

Inheritance

System.Object

Options

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

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

AlgebraOptimisation

Gets/Sets whether Algebra Optimisation should be used.

Declaration

public static bool AlgebraOptimisation { get; set; }

Property Value

Type	Description
System.Boolean

AllowMultiThreadedWriting

Gets/Sets whether multi-theaded writing is permitted.

Declaration

public static bool AllowMultiThreadedWriting { get; set; }

Property Value

Type	Description
System.Boolean

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.

DefaultComparisonOptions

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

Declaration

public static CompareOptions DefaultComparisonOptions { get; set; }

Property Value

Type	Description
System.Globalization.CompareOptions

Remarks

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

DefaultCompressionLevel

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

Declaration

public static int DefaultCompressionLevel { get; set; }

Property Value

Type	Description
System.Int32

DefaultCulture

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

Declaration

public static CultureInfo DefaultCulture { get; set; }

Property Value

Type	Description
System.Globalization.CultureInfo

Remarks

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

DefaultTokenQueueMode

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

Declaration

public static TokenQueueMode DefaultTokenQueueMode { get; set; }

Property Value

Type	Description
TokenQueueMode

ForceBlockingIO

Gets/Sets whether Blocking IO should be forced.

Declaration

public static bool ForceBlockingIO { get; set; }

Property Value

Type	Description
System.Boolean

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.

ForceHttpBasicAuth

Gets/Sets whether Basic HTTP authentication should be forced.

Declaration

public static bool ForceHttpBasicAuth { get; set; }

Property Value

Type	Description
System.Boolean

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.

FullTripleIndexing

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

Declaration

public static bool FullTripleIndexing { get; set; }

Property Value

Type	Description
System.Boolean

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.

HttpDebugging

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

Declaration

public static bool HttpDebugging { get; set; }

Property Value

Type	Description
System.Boolean

HttpFullDebugging

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

Declaration

public static bool HttpFullDebugging { get; set; }

Property Value

Type	Description
System.Boolean

InternUris

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

Declaration

public static bool InternUris { get; set; }

Property Value

Type	Description
System.Boolean

LiteralEqualityMode

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

Declaration

public static LiteralEqualityMode LiteralEqualityMode { get; set; }

Property Value

Type	Description
LiteralEqualityMode

LiteralValueNormalization

Gets/Sets whether Literal Values should be normalized.

Declaration

public static bool LiteralValueNormalization { get; set; }

Property Value

Type	Description
System.Boolean

QueryAllowUnknownFunctions

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

Declaration

public static bool QueryAllowUnknownFunctions { get; set; }

Property Value

Type	Description
System.Boolean

Remarks

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

QueryDefaultSyntax

Gets/Sets the default syntax used for parsing SPARQL queries.

Declaration

public static SparqlQuerySyntax QueryDefaultSyntax { get; set; }

Property Value

Type	Description
SparqlQuerySyntax

Remarks

The default is SPARQL 1.1 unless you use this property to change it.

QueryExecutionTimeout

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

Declaration

public static long QueryExecutionTimeout { get; set; }

Property Value

Type	Description
System.Int64

Remarks

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

QueryOptimisation

Gets/Sets whether Query Optimisation should be used.

Declaration

public static bool QueryOptimisation { get; set; }

Property Value

Type	Description
System.Boolean

RigorousEvaluation

Gets/Sets whether to use rigorous query evaluation.

Declaration

public static bool RigorousEvaluation { get; set; }

Property Value

Type	Description
System.Boolean

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.

StrictOperators

Gets/Sets whether to use strict operators.

Declaration

public static bool StrictOperators { get; set; }

Property Value

Type	Description
System.Boolean

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.

UnsafeOptimisation

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

Declaration

public static bool UnsafeOptimisation { get; set; }

Property Value

Type	Description
System.Boolean

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.

UpdateExecutionTimeout

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

Declaration

public static long UpdateExecutionTimeout { get; set; }

Property Value

Type	Description
System.Int64

Remarks

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

UriLoaderCaching

Gets/Sets whether the UriLoader uses caching.

Declaration

public static bool UriLoaderCaching { get; set; }

Property Value

Type	Description
System.Boolean

UriLoaderTimeout

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

Declaration

public static int UriLoaderTimeout { get; set; }

Property Value

Type	Description
System.Int32

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

public static bool UseBomForUtf8 { get; set; }

Property Value

Type	Description
System.Boolean

UseDtd

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

Declaration

public static bool UseDtd { get; set; }

Property Value

Type	Description
System.Boolean

UsePLinqEvaluation

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

Declaration

public static bool UsePLinqEvaluation { get; set; }

Property Value

Type	Description
System.Boolean

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.

ValidateIris

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

Declaration

public static bool ValidateIris { get; set; }

Property Value

Type	Description
System.Boolean

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.