Class Reference
IRIS for UNIX 2019.2
InterSystems: The power behind what matters   
Documentation  Search
  [%SYS] >  [SYS] >  [Database] >  [BackgroundFileCompact]
Private  Storage   

persistent class SYS.Database.BackgroundFileCompact extends %SYS.BackgroundTask

Class to start, monitor and control the Database Compaction utiltity running in the background. The method run in the background is the FileCompact method of SYS.Database.

To start it

	set oref=##class(SYS.Database.BackgroundFileCompact).Start(Directory,TargetFree)

Start returns an oref to an object of this class that can be inspected and reloaded to get status and progress updates. See superclass %SYS.BackgroundTask for detailed information on features of this object.


Parameters Properties Methods Queries Indices ForeignKeys Triggers
2 3 1


BlocksScanned CancelIsAvailable Class Database
DisplayType FinalStatus HasEnded Namespace
PID PauseIsAvailable ProgressCurrent ProgressTotal
ProgressUnits Request ResumeIsAvailable RunningState

%AddToSaveSet %AddToSyncSet %BMEBuilt %CheckConstraints
%CheckConstraintsForExtent %ClassIsLatestVersion %ClassName %ComposeOid
%ConstructClone %Delete %DeleteExtent %DeleteId
%DispatchClassMethod %DispatchGetModified %DispatchGetProperty %DispatchMethod
%DispatchSetModified %DispatchSetMultidimProperty %DispatchSetProperty %Exists
%ExistsId %Extends %GUID %GUIDSet
%GetLock %GetParameter %GetSwizzleObject %Id
%InsertBatch %IsA %IsModified %IsNull
%KillExtent %KillExtentData %LoadFromMemory %LockExtent
%LockId %New %NormalizeObject %ObjectIsNull
%ObjectModified %Oid %OnBeforeAddToSync %OnDetermineClass
%Open %OpenId %OriginalNamespace %PackageName
%PhysicalAddress %PurgeIndices %Reload %RemoveFromSaveSet
%ResolveConcurrencyConflict %RollBack %Save %SaveDirect
%SaveIndices %SerializeObject %SetModified %SortBegin
%SortEnd %SyncObjectIn %SyncTransport %UnlockExtent
%UnlockId %ValidateIndices %ValidateObject Cancel
Pause Resume Start


• parameter CANCELDISPOSITION = -1;
Disposition for cancel requests.

0 - not allowed
1 - polls for cancel requests
-1 - directly terminate the process

• parameter PAUSEDISPOSITION = -1;
Disposition for pause requests.

0 - not allowed
1 - polls for pause requests
-1 - directly pause the process


• property BlocksScanned as %Integer [ Calculated ];
Blocks scanned as part of compaction. This includes blocks that have been relocated, either explicity because they needed to be moved, or incidentally as part of the operation. Also includes blocks searched as required to move a big string storage block. The expected value is highly dependent on the physical structure of the databases and is hard to predict; it serves mostly as an indication of forward progress.
• property Database as %String;
Database directory on which to operate


• query List()
SQL Query :
SELECT %ID,StartTime,Database,RunningState,HasEnded,FinalStatus,ProgressCurrent,ProgressTotal,ProgressUnits
FROM SYS_Database.BackgroundFileCompact

Copyright (c) 2019 by InterSystems Corporation. Cambridge, Massachusetts, U.S.A. All rights reserved. Confidential property of InterSystems Corporation.