com.atlassian.confluence.upgrade.upgradetask
Class AddUniqueAttachmentIdConstraintToAttachmentDataUpgradeTask

java.lang.Object
  com.atlassian.confluence.upgrade.AbstractUpgradeTask
      com.atlassian.confluence.upgrade.upgradetask.AddUniqueAttachmentIdConstraintToAttachmentDataUpgradeTask

All Implemented Interfaces:

BackupSupport, DatabaseUpgradeTask, UpgradeTask

public class AddUniqueAttachmentIdConstraintToAttachmentDataUpgradeTask
extends AbstractUpgradeTask
implements DatabaseUpgradeTask

This task adds a unique constraint to the AttachmentId column on the AttachmentData table. Having multiple records for the one attachment id is an invalid state that causes errors (CONF-7882). In order to create the constraint this task does the following:

1. Deletes any attachmentdata records with no attachmentid.
2. Whenever there are multiple attachmentdata records for the same attachmentid, deletes all but the one with the lowest attachmentid.
3. For SQL Server only, removes all the indexes on the attachmentid column in the attachmentdata table.
4. Adds a not-null constraint on the attachmentid table, since unique constraints must be not-null on some DBs.
5. Adds the unique constraint on the attachmentid table.

This task does not need to run in an import or on setup of a new system because the constraints are included in the hibernate schema. It MUST run pre-upgrade because it relies on the SchemaHelper.updateSchemaIfNeeded() to re-create the indices in Sql Server. See dropIndicesFromSqlServer(ConfluenceHibernateConfig).

Constructor Summary

AddUniqueAttachmentIdConstraintToAttachmentDataUpgradeTask(net.sf.hibernate.SessionFactory sessionFactory, AlterTableExecutor alterTableExecutor, DdlExecutor ddlExecutor, org.springframework.transaction.PlatformTransactionManager transactionManager)

Method Summary

boolean	breaksBackwardCompatibility() Returns true if a new export can't be imported in an older instance.
void	doUpgrade() Perform the upgrade.
java.lang.String	getBuildNumber()
java.lang.String	getShortDescription() A short (<50 chars) description of the upgrade action
boolean	runOnSpaceImport() Returns true if an older Space can't be imported in a new instance without running this task.

Methods inherited from class com.atlassian.confluence.upgrade.AbstractUpgradeTask

addAllErrors, addError, addError, getConstraint, getErrors, setBuildNumber, validate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.atlassian.confluence.upgrade.UpgradeTask

getConstraint, getErrors, validate

Constructor Detail

AddUniqueAttachmentIdConstraintToAttachmentDataUpgradeTask

public AddUniqueAttachmentIdConstraintToAttachmentDataUpgradeTask(net.sf.hibernate.SessionFactory sessionFactory,
                                                                  AlterTableExecutor alterTableExecutor,
                                                                  DdlExecutor ddlExecutor,
                                                                  org.springframework.transaction.PlatformTransactionManager transactionManager)

Method Detail

getBuildNumber

public java.lang.String getBuildNumber()

Specified by:

getBuildNumber in interface UpgradeTask

Overrides:

getBuildNumber in class AbstractUpgradeTask

Returns:

The build number that this upgrade is applicable to

getShortDescription

public java.lang.String getShortDescription()

Description copied from interface: UpgradeTask

A short (<50 chars) description of the upgrade action

Specified by:

getShortDescription in interface UpgradeTask

Overrides:

getShortDescription in class AbstractUpgradeTask

doUpgrade

public void doUpgrade()
               throws java.lang.Exception

Description copied from interface: UpgradeTask

Perform the upgrade.

Specified by:

doUpgrade in interface UpgradeTask

Throws:

java.lang.Exception

runOnSpaceImport

public boolean runOnSpaceImport()

Description copied from interface: BackupSupport

Returns true if an older Space can't be imported in a new instance without running this task. For example:

• A task updating macro names in the BodyContent table would be blocking.
• Tasks which updates data related to the space would be blocking.
• A task upgrading the user table wouldn't be blocking.
• Adding a mandatory column on space-related content breaks space import

Note that tasks don't run on space import yet, so we just reject the import in this case.

Specified by:

runOnSpaceImport in interface BackupSupport

breaksBackwardCompatibility

public boolean breaksBackwardCompatibility()

Description copied from interface: BackupSupport

Returns true if a new export can't be imported in an older instance. Breaking compatibility means a snapshot of the new version will not work at all with the previous version. For example:

• A destructive operation (Some data is replaced by another) breaks backwards compatibility
• Adding a optional column does NOT break backwards compatibility
• Data is copied to another column doesn't breaks backwards compatibility
• A build number incrementation doesn't breaks backwards compatibility

The best way to test is whether a newer export can be imported (with fully working features) in an older instance.

Specified by:

breaksBackwardCompatibility in interface BackupSupport