StatementCache (Apache Derby V10.14 Internals)

java.lang.Object
- org.apache.derby.vti.VTITemplate
- - org.apache.derby.diag.StatementCache

All Implemented Interfaces:

java.lang.AutoCloseable, java.sql.ResultSet, java.sql.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 org.apache.derby.vti.VTITemplate
  VTITemplate.ColumnDescriptor

Field Summary

Fields
Modifier and Type	Field	Description
`private static ResultColumnDescriptor[]`	`columnInfo`
`private GenericPreparedStatement`	`currentPs`
`private java.util.Vector<GenericPreparedStatement>`	`data`
`private static java.sql.ResultSetMetaData`	`metadata`
`private int`	`position`
`private boolean`	`wasNull`

Fields inherited from interface java.sql.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()

Constructors
Constructor	Description
`StatementCache()`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`
`boolean`	`getBoolean(int colId)`
`private static Context`	`getContextOrNull(java.lang.String contextID)`	Privileged lookup of a Context.
`java.sql.ResultSetMetaData`	`getMetaData()`
`java.lang.String`	`getString(int colId)`
`java.sql.Timestamp`	`getTimestamp(int colId)`
`boolean`	`next()`
`boolean`	`wasNull()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.sql.ResultSet
updateObject, updateObject, updateObject, updateObject

Methods inherited from class org.apache.derby.vti.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

- Field Detail
  - position
```
private int position
```
  - data
```
private java.util.Vector<GenericPreparedStatement> data
```
  - currentPs
```
private GenericPreparedStatement currentPs
```
  - wasNull
```
private boolean wasNull
```
  - columnInfo
```
private static final ResultColumnDescriptor[] columnInfo
```
  - metadata
```
private static final java.sql.ResultSetMetaData metadata
```
- Constructor Detail
  - StatementCache
```
public StatementCache()
               throws StandardException
```
    Throws:
    
    StandardException
- Method Detail
  - next
```
public boolean next()
```
  - close
```
public void close()
```
  - getString
```
public java.lang.String getString(int colId)
```
    Specified by:
    
    getString in interface java.sql.ResultSet
    
    Overrides:
    
    getString in class VTITemplate
  - getBoolean
```
public boolean getBoolean(int colId)
```
    Specified by:
    
    getBoolean in interface java.sql.ResultSet
    
    Overrides:
    
    getBoolean in class VTITemplate
  - getTimestamp
```
public java.sql.Timestamp getTimestamp(int colId)
```
    Specified by:
    
    getTimestamp in interface java.sql.ResultSet
    
    Overrides:
    
    getTimestamp in class VTITemplate
  - wasNull
```
public boolean wasNull()
```
    Specified by:
    
    wasNull in interface java.sql.ResultSet
    
    Overrides:
    
    wasNull in class VTITemplate
  - getMetaData
```
public java.sql.ResultSetMetaData getMetaData()
```
    Specified by:
    
    getMetaData in interface java.sql.ResultSet
    
    Overrides:
    
    getMetaData in class VTITemplate
  - getContextOrNull
```
private static Context getContextOrNull(java.lang.String contextID)
```
    Privileged lookup of a Context. Must be private so that user code can't call this entry point.

Class StatementCache

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.derby.vti.VTITemplate

Field Summary

Fields inherited from interface java.sql.ResultSet

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.sql.ResultSet

Methods inherited from class org.apache.derby.vti.VTITemplate

Field Detail

position

data

currentPs

wasNull

columnInfo

metadata

Constructor Detail

StatementCache

Method Detail

next

close

getString

getBoolean

getTimestamp

wasNull

getMetaData

getContextOrNull