Frozen Files and Partitions

A convenient way to freeze a large number of JADE objects is to freeze a database file or partition. In effect, this makes all objects read from that file or partition frozen. This reduces the number of lock and unlock requests, and brings about the same overhead savings as if the objects had been frozen individually.

Frozen partitions can be used for a class where the partition for instances is determined by a date attribute. Partitions containing old, historical data could be marked frozen. Specific examples include sales or orders, banking transactions, test results, meter readings, and so on.

Use the JADE Database Administration utility to freeze files. The following example shows how to freeze the first (oldest) partition of MyFile.

jdbadmin ini=iniFile path=system action=Freeze file=MyFile partition=1

Freezing a file or partition overrides any specified object volatility for all instances defined in that file or partition. This means a volatile or stable object stored in a frozen file or partition is treated as a frozen object when the object is read. The objects can be reverted to their actual volatility, by thawing the file or partition.

Use the JADE Database Administration utility to thaw files. The following example shows how to thaw the first (oldest) partition of MyFile.

jdbadmin ini=iniFile path=system action=Thaw file=MyFile partition=1

For more details, see ''Using the JADE Database Administration Utility", in Chapter 2 of the JADE Database Administration Guide.

Modify the backup strategy to take advantage of the fact that frozen files or partitions cannot be updated, so do not need to be backed up as frequently.