com.continuent.tungsten.replicator.prefetch
Class KeySelect

java.lang.Object
  com.continuent.tungsten.replicator.prefetch.KeySelect

public class KeySelect
extends java.lang.Object

Encapsulates data and statement generation logic for prefetching slices of indexes. This includes holding the key definition as well as the associated values we are selecting from the key.

Constructor Summary

KeySelect(Table table, Key key)
Create a new instance.

Method Summary

java.lang.String	createPrefetchSelect() Creates generic prefetch prepared statement text appropriate to the index type including drop-outs for key values.
java.lang.String	generateKey() Returns a reasonably efficient key for this select that incorporates both the fully qualified key name as well as select values.
Key	getKey()
long	getLastInvocation()
Table	getTable()
java.lang.Object	getValue(int index) Gets a column value by index.
java.lang.Object	getValue(java.lang.String colName) Gets a column value by name.
java.util.List<java.lang.Object>	getValues()
boolean	hasNulls() Returns true if any of the values in the key select is a null.
void	setLastInvocation(long lastInvocation)
void	setValue(int index, java.lang.Object value) Sets a column value for the select.
void	setValue(java.lang.String colName, java.lang.Object value) Sets a column value for the select.
int	size() Returns the number of columns in the key.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

KeySelect

public KeySelect(Table table,
                 Key key)

Create a new instance.

Method Detail

getTable

public Table getTable()

getKey

public Key getKey()

getValues

public java.util.List<java.lang.Object> getValues()

getLastInvocation

public long getLastInvocation()

setLastInvocation

public void setLastInvocation(long lastInvocation)

size

public int size()

Returns the number of columns in the key.

hasNulls

public boolean hasNulls()

Returns true if any of the values in the key select is a null.

setValue

public void setValue(int index,
                     java.lang.Object value)
              throws ReplicatorException

Sets a column value for the select.

Parameters:

index - Column index in key where 1 is the first index

value - Value to set

Throws:

ReplicatorException

getValue

public java.lang.Object getValue(int index)

Gets a column value by index.

Parameters:

index - Column index in key where 1 is the first index

setValue

public void setValue(java.lang.String colName,
                     java.lang.Object value)
              throws ReplicatorException

Sets a column value for the select.

Parameters:

colName - Name of the column in key

value - Value to set

Throws:

ReplicatorException

getValue

public java.lang.Object getValue(java.lang.String colName)
                          throws ReplicatorException

Gets a column value by name.

Parameters:

colName - Name of the column in key

Throws:

ReplicatorException

createPrefetchSelect

public java.lang.String createPrefetchSelect()

Creates generic prefetch prepared statement text appropriate to the index type including drop-outs for key values. For a primary key, we use SELECT * to force reading of the base data, whereas for a secondary index we use SELECT count(*), which reads only index pages.

generateKey

public java.lang.String generateKey()

Returns a reasonably efficient key for this select that incorporates both the fully qualified key name as well as select values. This key can be used for caching information about this particular index prefetch query.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

See Also:

Object.toString()