ForgottenKnowledge Class

Represents knowledge that has been forgotten because of tombstone cleanup.

System.Object
  Microsoft.Synchronization.SyncKnowledge
    Microsoft.Synchronization.ForgottenKnowledge

Namespace:  Microsoft.Synchronization
Assembly:  Microsoft.Synchronization (in Microsoft.Synchronization.dll)

'Declaration
<SerializableAttribute> _
Public Class ForgottenKnowledge _
	Inherits SyncKnowledge _
	Implements ISerializable
'Usage
Dim instance As ForgottenKnowledge

The ForgottenKnowledge type exposes the following members.

  NameDescription
Public methodForgottenKnowledgeInitializes a new instance of the ForgottenKnowledge class.
Protected methodForgottenKnowledge(SerializationInfo, StreamingContext)Initializes a new instance of the ForgottenKnowledge class by using serialized data.
Public methodForgottenKnowledge(SyncIdFormatGroup, SyncKnowledge)Initializes a new instance of the ForgottenKnowledge class that contains the specified ID format schema and synchronization knowledge.
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  NameDescription
Public propertyCompatibilityLevelGets or sets the version of Sync Framework components that can be used with this object. (Inherited from SyncKnowledge.)
Public propertyMinimumCompatibilityLevelGets the minimum version of Sync Framework components that can be used with this object. (Inherited from SyncKnowledge.)
Public propertyReplicaIdGets the ID of the replica that owns this knowledge. (Inherited from SyncKnowledge.)
Public propertyReplicaKeyMapGets the replica key map that is associated with this knowledge. (Inherited from SyncKnowledge.)
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  NameDescription
Public methodAddMarkerMarks the specified item with the specified marker type. (Inherited from SyncKnowledge.)
Public methodCloneCreates a new ForgottenKnowledge object and copies the forgotten knowledge into it. (Overrides SyncKnowledge.Clone.)
Public methodCombineCombines the specified knowledge with the current knowledge. (Inherited from SyncKnowledge.)
Public methodComparePerforms a fast comparison between the specified knowledge cookie and this knowledge object. (Inherited from SyncKnowledge.)
Public methodComplementReturns the knowledge that is contained in this object, but that is not contained in the specified knowledge. (Inherited from SyncKnowledge.)
Public methodContains(ChangeUnitChange)Indicates whether the specified change unit change is known by this knowledge. (Inherited from SyncKnowledge.)
Public methodContains(ItemChange)Indicates whether the specified item change is known by this knowledge. (Inherited from SyncKnowledge.)
Public methodContains(SyncKnowledge)Indicates whether the specified knowledge is known by this knowledge. (Inherited from SyncKnowledge.)
Public methodContains(SyncId, SyncId, SyncVersion)Indicates whether the specified item change is known by this knowledge. (Inherited from SyncKnowledge.)
Public methodContains(SyncId, SyncId, SyncId, SyncVersion)Indicates whether the specified change unit change is known by this knowledge. (Inherited from SyncKnowledge.)
Public methodContainsMarkerIndicates whether the specified item is marked with the specified marker type. (Inherited from SyncKnowledge.)
Public methodStatic memberDeserializeDeserializes a forgotten knowledge instance from the specified byte array.
Public methodEquals (Inherited from Object.)
Public methodExcludeChangeUnitRemoves knowledge about the specified change unit from the knowledge. (Inherited from SyncKnowledge.)
Public methodExcludeItemRemoves knowledge about the specified item from the knowledge. (Inherited from SyncKnowledge.)
Protected methodFinalize (Inherited from Object.)
Public methodFindMinTickCountForReplicaFinds the minimum tick count in the knowledge for the specified replica. (Inherited from SyncKnowledge.)
Public methodForgetToUpdates the forgotten knowledge to reflect that all versions less than or equal to the specified version might have been forgotten, and that corresponding tombstones might have been deleted.
Public methodGetHashCode (Inherited from Object.)
Public methodGetKnowledgeCookieGets a lightweight, read-only representation of this knowledge object that can be used for fast comparisons. (Inherited from SyncKnowledge.)
Public methodGetKnowledgeForChangeUnitGets the knowledge for the specified change unit. (Inherited from SyncKnowledge.)
Public methodGetKnowledgeForColumnsReturns the knowledge for the specified set of change units for all the items that are contained in this object. (Inherited from SyncKnowledge.)
Public methodGetKnowledgeForItemGets the knowledge for the specified item. (Inherited from SyncKnowledge.)
Public methodGetKnowledgeForRangeGets the knowledge for the specified range of item IDs. (Inherited from SyncKnowledge.)
Public methodGetObjectDataSerializes the forgotten knowledge to the specified SerializationInfo object. (Overrides SyncKnowledge.GetObjectData(SerializationInfo, StreamingContext).)
Public methodGetSchemaReturns a Nothing. (Inherited from SyncKnowledge.)
Public methodGetSyncIdFormatGroupGets the ID format schema of the IDs that are stored in this knowledge object. (Inherited from SyncKnowledge.)
Public methodGetType (Inherited from Object.)
Public methodIntersectsIndicates whether the specified knowledge intersects with this knowledge. (Inherited from SyncKnowledge.)
Public methodMapRemoteKnowledgeToLocalConverts a knowledge object from another replica into one that is compatible with the replica that owns this knowledge. (Inherited from SyncKnowledge.)
Protected methodMemberwiseClone (Inherited from Object.)
Public methodReadXmlReconstitutes the object from its XML representation. (Inherited from SyncKnowledge.)
Public methodRemoveAllChangeUnitsMarkersRemoves all markers for items in the knowledge. (Inherited from SyncKnowledge.)
Public methodRemoveMarkerRemoves a marker of the specified type from the specified item. (Inherited from SyncKnowledge.)
Public methodSerializeSerializes the knowledge object data to a byte array. (Inherited from SyncKnowledge.)
Public methodSerialize(Boolean)Serializes the knowledge object data to a byte array. (Inherited from SyncKnowledge.)
Public methodSetLocalTickCountSets the tick count for the replica that owns this knowledge. (Inherited from SyncKnowledge.)
Public methodToStringGets a string that represents the knowledge. (Inherited from SyncKnowledge.)
Public methodWriteXmlConverts this object into its XML representation. (Inherited from SyncKnowledge.)
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The forgotten knowledge tracks the maximum version of tombstones that have been cleaned up. When an item is deleted from the item store, the metadata for that item is kept, but the item is marked as deleted. Metadata for a deleted item is called a tombstone. Tombstones must be periodically cleaned up or they will eventually use too much space in the item store. When a tombstone is removed from the metadata, the forgotten knowledge must be updated to contain the version of the removed tombstone. Be aware that forgotten knowledge is an overestimation of which items have had their metadata removed. Therefore, the forgotten knowledge might also contain items that still have active entries in the metadata.

Sync Framework uses the forgotten knowledge to detect an out-of-date synchronization destination. For more information, see Managing Tombstones and Recovering an Out-of-Date Replica.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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