Summary of Change

A bug that could cause unrecoverable database corruption has been fixed.

Symptoms Seen by Applications Affected by Change

A bug that could cause database corruption was introduced in the 10.3 codeline and affects the following releases:

Users who are hit by this bug may experience exceptions at various times during execution of SQL statements, booting or shutdown of a database, or during checkpointing. It may result in a number of different error messages, including any of these: 

ERROR XSDB3: Container information cannot change once written: was 0, now 80
ERROR XSDG1: Page Page(1039,Container(0, 5856)) could not be written to disk, please check if disk is full.
ERROR XSDG2: Invalid checksum on Page Page(0,Container(0, 1313))
ERROR XSDG3: Meta-data for Container org.apache.derby.impl.store.raw.data.RAFContainer4@1afb0c7 could not be accessed
ERROR XSLA1: Log Record has been sent to the stream, but it cannot be applied to the store (Object null). This may cause recovery problems also.

Incompatibilities with Previous Release

None.

Rationale for Change

Database corruption is bad.

Application Changes Required

No changes are required. However, since the database corruption may go unnoticed for a while, users may want to check the consistency of their databases after upgrading Derby. The process is described on the following wiki page: http://wiki.apache.org/db-derby/DatabaseConsistencyCheck . If a corruption is detected, restoring the database from backup is the only reliable way to recover.