Class StatementCache

java.lang.Object

org.apache.derby.vti.VTITemplate

org.apache.derby.diag.StatementCache

All Implemented Interfaces:

AutoCloseable, ResultSet, Wrapper, AwareVTI

public final class StatementCache
extends VTITemplate

StatementCache is a virtual table that shows the contents of the SQL statement cache. This virtual table can be invoked by calling it directly.

 select * from new org.apache.derby.diag.StatementCache() t

The StatementCache virtual table has the following columns:

• ID CHAR(36) - not nullable. Internal identifier of the compiled statement.
• SCHEMANAME VARCHAR(128) - nullable. Schema the statement was compiled in.
• SQL_TEXT VARCHAR(32672) - not nullable. Text of the statement
• UNICODE BIT/BOOLEAN - not nullable. Always true.
• VALID BIT/BOOLEAN - not nullable. True if the statement is currently valid, false otherwise
• COMPILED_AT TIMESTAMP nullable - time statement was compiled, requires STATISTICS TIMING to be enabled.

The internal identifier of a cached statement matches the toString() method of a PreparedStatement object for a Derby database.

This class also provides a static method to empty the statement cache, StatementCache.emptyCache()

Nested Class Summary

Nested classes/interfaces inherited from class VTITemplate

VTITemplate.ColumnDescriptor

Field Summary

Fields

Modifier and Type	Field	Description
private static final ResultColumnDescriptor[]	columnInfo
private GenericPreparedStatement	currentPs
private Vector<GenericPreparedStatement>	data
private static final ResultSetMetaData	metadata
private int	position
private boolean	wasNull

Fields inherited from interface ResultSet

CLOSE_CURSORS_AT_COMMIT, CONCUR_READ_ONLY, CONCUR_UPDATABLE, FETCH_FORWARD, FETCH_REVERSE, FETCH_UNKNOWN, HOLD_CURSORS_OVER_COMMIT, TYPE_FORWARD_ONLY, TYPE_SCROLL_INSENSITIVE, TYPE_SCROLL_SENSITIVE

Constructor Summary

Constructors

Constructor	Description
StatementCache()

Method Summary

Modifier and Type	Method	Description
void	close()
boolean	getBoolean(int colId)
private static Context	getContextOrNull(String contextID)	Privileged lookup of a Context.
ResultSetMetaData	getMetaData()
String	getString(int colId)
Timestamp	getTimestamp(int colId)
boolean	next()
boolean	wasNull()

Methods inherited from class VTITemplate

absolute, afterLast, beforeFirst, cancelRowUpdates, clearWarnings, deleteRow, findColumn, first, getArray, getArray, getAsciiStream, getAsciiStream, getBigDecimal, getBigDecimal, getBigDecimal, getBigDecimal, getBinaryStream, getBinaryStream, getBlob, getBlob, getBoolean, getByte, getByte, getBytes, getBytes, getCharacterStream, getCharacterStream, getClob, getClob, getConcurrency, getContext, getCursorName, getDate, getDate, getDate, getDate, getDouble, getDouble, getFetchDirection, getFetchSize, getFloat, getFloat, getHoldability, getInt, getInt, getLong, getLong, getNCharacterStream, getNCharacterStream, getNClob, getNClob, getNString, getNString, getObject, getObject, getObject, getObject, getObject, getObject, getRef, getRef, getReturnTableSignature, getRow, getRowId, getRowId, getShort, getShort, getSQLXML, getSQLXML, getStatement, getString, getTime, getTime, getTime, getTime, getTimestamp, getTimestamp, getTimestamp, getType, getUnicodeStream, getUnicodeStream, getURL, getURL, getWarnings, insertRow, isAfterLast, isBeforeFirst, isClosed, isFirst, isLast, isWrapperFor, last, moveToCurrentRow, moveToInsertRow, notImplemented, previous, refreshRow, relative, rowDeleted, rowInserted, rowUpdated, setContext, setFetchDirection, setFetchSize, unwrap, updateArray, updateArray, updateAsciiStream, updateAsciiStream, updateAsciiStream, updateAsciiStream, updateAsciiStream, updateAsciiStream, updateBigDecimal, updateBigDecimal, updateBinaryStream, updateBinaryStream, updateBinaryStream, updateBinaryStream, updateBinaryStream, updateBinaryStream, updateBlob, updateBlob, updateBlob, updateBlob, updateBlob, updateBlob, updateBoolean, updateBoolean, updateByte, updateByte, updateBytes, updateBytes, updateCharacterStream, updateCharacterStream, updateCharacterStream, updateCharacterStream, updateCharacterStream, updateCharacterStream, updateClob, updateClob, updateClob, updateClob, updateClob, updateClob, updateDate, updateDate, updateDouble, updateDouble, updateFloat, updateFloat, updateInt, updateInt, updateLong, updateLong, updateNCharacterStream, updateNCharacterStream, updateNCharacterStream, updateNCharacterStream, updateNClob, updateNClob, updateNClob, updateNClob, updateNClob, updateNClob, updateNString, updateNString, updateNull, updateNull, updateObject, updateObject, updateObject, updateObject, updateRef, updateRef, updateRow, updateRowId, updateRowId, updateShort, updateShort, updateSQLXML, updateSQLXML, updateString, updateString, updateTime, updateTime, updateTimestamp, updateTimestamp

Methods inherited from class Object

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

Methods inherited from interface ResultSet

updateObject, updateObject, updateObject, updateObject

Field Details

position

private int position

data

private Vector<GenericPreparedStatement> data

currentPs

private GenericPreparedStatement currentPs

wasNull

private boolean wasNull

columnInfo

private static final ResultColumnDescriptor[] columnInfo

metadata

private static final ResultSetMetaData metadata

Constructor Details

StatementCache

public StatementCache()
               throws StandardException

Throws:

StandardException

Method Details

next

public boolean next()

close

public void close()

getString

public String getString(int colId)

Specified by:

getString in interface ResultSet

Overrides:

getString in class VTITemplate

getBoolean

public boolean getBoolean(int colId)

Specified by:

getBoolean in interface ResultSet

Overrides:

getBoolean in class VTITemplate

getTimestamp

public Timestamp getTimestamp(int colId)

Specified by:

getTimestamp in interface ResultSet

Overrides:

getTimestamp in class VTITemplate

wasNull

public boolean wasNull()

Specified by:

wasNull in interface ResultSet

Overrides:

wasNull in class VTITemplate

getMetaData

public ResultSetMetaData getMetaData()

Specified by:

getMetaData in interface ResultSet

Overrides:

getMetaData in class VTITemplate

getContextOrNull

private static Context getContextOrNull(String contextID)

Privileged lookup of a Context. Must be private so that user code can't call this entry point.