net.sf.hajdbc.sync

Class DifferentialSynchronizationStrategy

java.lang.Object

net.sf.hajdbc.sync.DifferentialSynchronizationStrategy

All Implemented Interfaces:

Serializable, Identifiable, TableSynchronizationStrategy, SynchronizationStrategy

public class DifferentialSynchronizationStrategy
extends Object
implements SynchronizationStrategy, TableSynchronizationStrategy

Database-independent synchronization strategy that only updates differences between two databases. This strategy is best used when there are few differences between the active database and the inactive database (i.e. barely out of sync). The following algorithm is used:

1. Drop the foreign keys on the inactive database (to avoid integrity constraint violations)
2. For each database table:
   1. Drop the unique constraints on the table (to avoid integrity constraint violations)
   2. Find the primary key(s) of the table
   3. Query all rows in the inactive database table, sorting by the primary key(s)
   4. Query all rows on the active database table
   5. For each row in table:
      1. If primary key of the rows are the same, determine whether or not row needs to be updated
      2. Otherwise, determine whether row should be deleted, or a new row is to be inserted
   6. Re-create the unique constraints on the table (to avoid integrity constraint violations)
3. Re-create the foreign keys on the inactive database
4. Synchronize sequences

Author:

Paul Ferraro

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
DifferentialSynchronizationStrategy()

Method Summary

Methods

Modifier and Type	Method and Description
<Z,D extends Database<Z>> void	destroy(DatabaseCluster<Z,D> cluster)
<Z,D extends Database<Z>> void	dropConstraints(SynchronizationContext<Z,D> context)
int	getFetchSize()
String	getId()
int	getMaxBatchSize()
String	getVersionPattern()
<Z,D extends Database<Z>> void	init(DatabaseCluster<Z,D> cluster)
<Z,D extends Database<Z>> void	restoreConstraints(SynchronizationContext<Z,D> context)
void	setFetchSize(int fetchSize)
void	setMaxBatchSize(int maxBatchSize)
void	setVersionPattern(String versionPattern)
<Z,D extends Database<Z>> void	synchronize(SynchronizationContext<Z,D> context) Synchronizes a target database with a source database as defined by the synchronization context.
<Z,D extends Database<Z>> void	synchronize(SynchronizationContext<Z,D> context, TableProperties table)

Methods inherited from class java.lang.Object

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

Constructor Detail

DifferentialSynchronizationStrategy

public DifferentialSynchronizationStrategy()

Method Detail

getId

public String getId()

Specified by:

getId in interface Identifiable

synchronize

public <Z,D extends Database<Z>> void synchronize(SynchronizationContext<Z,D> context)
                 throws SQLException

Description copied from interface: SynchronizationStrategy

Synchronizes a target database with a source database as defined by the synchronization context.

Specified by:

synchronize in interface SynchronizationStrategy

Parameters:

context - a synchronization context

Throws:

SQLException - if synchronization fails

init

public <Z,D extends Database<Z>> void init(DatabaseCluster<Z,D> cluster)

Specified by:

init in interface SynchronizationStrategy

See Also:

SynchronizationStrategy.init(net.sf.hajdbc.DatabaseCluster)

destroy

public <Z,D extends Database<Z>> void destroy(DatabaseCluster<Z,D> cluster)

Specified by:

destroy in interface SynchronizationStrategy

See Also:

SynchronizationStrategy.destroy(net.sf.hajdbc.DatabaseCluster)

dropConstraints

public <Z,D extends Database<Z>> void dropConstraints(SynchronizationContext<Z,D> context)
                     throws SQLException

Specified by:

dropConstraints in interface TableSynchronizationStrategy

Throws:

SQLException

restoreConstraints

public <Z,D extends Database<Z>> void restoreConstraints(SynchronizationContext<Z,D> context)
                        throws SQLException

Specified by:

restoreConstraints in interface TableSynchronizationStrategy

Throws:

SQLException

synchronize

public <Z,D extends Database<Z>> void synchronize(SynchronizationContext<Z,D> context,
                                         TableProperties table)
                 throws SQLException

Specified by:

synchronize in interface TableSynchronizationStrategy

Throws:

SQLException

See Also:

SynchronizationStrategy.synchronize(net.sf.hajdbc.sync.SynchronizationContext)

getFetchSize

public int getFetchSize()

Returns:

the fetchSize.

setFetchSize

public void setFetchSize(int fetchSize)

Parameters:

fetchSize - the fetchSize to set.

getMaxBatchSize

public int getMaxBatchSize()

Returns:

Returns the maxBatchSize.

setMaxBatchSize

public void setMaxBatchSize(int maxBatchSize)

Parameters:

maxBatchSize - The maxBatchSize to set.

getVersionPattern

public String getVersionPattern()

Returns:

the versionPattern

setVersionPattern

public void setVersionPattern(String versionPattern)

Parameters:

versionPattern - the versionPattern to set