Class QueryOptions

Cache query options.

Inheritance

object

QueryOptions

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Apache.Ignite.Linq

Assembly: Apache.Ignite.Linq.dll

Syntax

public class QueryOptions

Constructors

QueryOptions()

Initializes a new instance of the QueryOptions class.

Declaration

public QueryOptions()

Fields

DefaultPageSize

Default page size.

Declaration

public const int DefaultPageSize = 1024

Field Value

Type	Description
int

DefaultUpdateBatchSize

Default value for UpdateBatchSize.

Declaration

public const int DefaultUpdateBatchSize = 1

Field Value

Type	Description
int

Properties

Colocated

Gets or sets a value indicating whether this query operates on colocated data.

Whenever Ignite executes a distributed query, it sends sub-queries to individual cluster members. If you know in advance that the elements of your query selection are colocated together on the same node and you group by colocated key (primary or affinity key), then Ignite can make significant performance and network optimizations by grouping data on remote nodes.

Declaration

public bool Colocated { get; set; }

Property Value

Type	Description
bool

EnableDistributedJoins

Gets or sets a value indicating whether distributed joins should be enabled for this query.

When disabled, join results will only contain colocated data (joins work locally). When enabled, joins work as expected, no matter how the data is distributed.

Declaration

public bool EnableDistributedJoins { get; set; }

Property Value

Type	Description
bool	true if enable distributed joins should be enabled; otherwise, false.

EnforceJoinOrder

Gets or sets a value indicating whether join order of tables should be enforced.

When true, query optimizer will not reorder tables in join.

It is not recommended to enable this property until you are sure that your indexes and the query itself are correct and tuned as much as possible but query optimizer still produces wrong join order.

Declaration

public bool EnforceJoinOrder { get; set; }

Property Value

Type	Description
bool	true if join order should be enforced; otherwise, false.

Label

Gets or sets the query label.

The specified label can be used to identify the running query in system views and in the log when printing warnings about long-running queries.

Declaration

public string Label { get; set; }

Property Value

Type	Description
string

Lazy

Gets or sets a value indicating whether this query is lazy.

By default Ignite attempts to fetch the whole query result set to memory and send it to the client. For small and medium result sets this provides optimal performance and minimize duration of internal database locks, thus increasing concurrency.

If result set is too big to fit in available memory this could lead to excessive GC pauses and even OutOfMemoryError. Use this flag as a hint for Ignite to fetch result set lazily, thus minimizing memory consumption at the cost of moderate performance hit.

Declaration

public bool Lazy { get; set; }

Property Value

Type	Description
bool

Local

Local flag. When set query will be executed only on local node, so only local entries will be returned as query result.

Defaults to false.

Declaration

public bool Local { get; set; }

Property Value

Type	Description
bool

PageSize

Page size, defaults to DefaultPageSize.

Declaration

public int PageSize { get; set; }

Property Value

Type	Description
int

Partitions

Gets or sets partitions for the query.

The query will be executed only on nodes which are primary for specified partitions.

Declaration

[SuppressMessage("Microsoft.Performance", "CA1819:PropertiesShouldNotReturnArrays")]
public int[] Partitions { get; set; }

Property Value

Type	Description
int[]

ReplicatedOnly

Gets or sets a value indicating whether this query contains only replicated tables. This is a hint for potentially more effective execution.

Declaration

[Obsolete("No longer used as of Apache Ignite 2.8.")]
public bool ReplicatedOnly { get; set; }

Property Value

Type	Description
bool

TableName

Gets or sets the name of the table.

Table name is equal to short class name of a cache value. When a cache has only one type of values, or only one QueryEntity defined, table name will be inferred and can be omitted (null).

Declaration

public string TableName { get; set; }

Property Value

Type	Description
string	The name of the table.

Timeout

Gets or sets the query timeout. Query will be automatically cancelled if the execution timeout is exceeded. Default is Zero, which means no timeout.

Declaration

public TimeSpan Timeout { get; set; }

Property Value

Type	Description
TimeSpan

UpdateBatchSize

Gets or sets batch size for update queries.

Default is 1 (DefaultUpdateBatchSize.

Declaration

public int UpdateBatchSize { get; set; }

Property Value

Type	Description
int