1.1.1

Table Of Contents
Ofine compaction runs essentially in the same way, but without the incoming DML operations. Also, because
there is no current open log, the compaction creates a new one to get started.
Run Online Compaction
Old log les become eligible for online compaction when their garbage content surpasses a congured percentage
of the total le. A record is garbage when its operation is superseded by a more recent operation for the same
record. During compaction, the non-garbage records are added to the current log along with new DML operations.
Online compaction does not block current system operations.
Run automatic compaction. When AUTOCOMPACT is true, SQLFire automatically compacts each oplog when
its garbage content surpasses the COMPACTIONTHRESHOLD. Automatic compaction takes cycles from your
other operations, so you may want to disable it and only do manual compaction, to control the timing.
Run manual compaction. To run manual compaction:
Set the disk store attribute ALLOWFORCECOMPACTION to true. This causes SQLFire to maintain extra data
about the les so that it can compact on demand. This is disabled by default to save space. You can run manual
online compaction at any time while the system is running. Oplogs eligible for compaction based on the
COMPACTIONTHRESHOLD are compacted into the current oplog.
Run manual compaction as needed. You can compact all online disk stores in a distributed system from the
command-line. For example:
sqlf compact-all-disk-stores
Note: This sqlf command requires a local sqlfire.properties le that contains properties
to locate the distributed system. Or, specify the multicast port or locator properties to connect to the
cluster (for example, -mcast-port= port_number).
Run Offline Compaction
Ofine compaction is a manual process. All log les are compacted as much as possible, regardless of how
much garbage they hold. Ofine compaction creates new log les for the compacted log records.
Use this syntax to compact individual ofine disk stores:
sqlf compact-disk-store myDiskStoreName /firstDir /secondDir
-maxOplogSize=maxMegabytesForOplog
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Managing Your Data in vFabric SQLFire