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java.lang.Objectorg.apache.derby.vti.VTITemplate
org.apache.derby.diag.SpaceTable
SpaceTable is a virtual table that shows the space usage of a particular table and its indexes. This virtual table can be invoked by calling it directly, and supplying the schema name and table name as arguments.
select * from new org.apache.derby.diag.SpaceTable('MYSCHEMA','MYTABLE') t;If the schema name is not supplied, the default schema is used.
select * from new org.apache.derby.diag.SpaceTable('MYTABLE') t;Alternatively, the table can be invoked through the system alias SpaceTable
select * from new SPACETABLE('MYTABLE') t;
NOTE: Both the schema name and the table name must be any expression that evaluates to a string data type. If you created a schema or table name as a non-delimited identifier, you must present their names in all upper case.
The SpaceTable virtual table can be used to estimate whether space might be saved by compressing a table and its indexes.
The SpaceTable virtual table has the following columns:
To get space information on all schemas and tables, use a query such as
select v.* from SYS.SYSSCHEMAS s, SYS.SYSTABLES t, new org.apache.derby.diag.SpaceTable(SCHEMANAME,TABLENAME) v where s.SCHEMAID = t.SCHEMAID;
Field Summary | |
private static ResultColumnDescriptor[] |
columnInfo
|
private ConglomInfo[] |
conglomTable
|
(package private) int |
currentRow
|
(package private) boolean |
initialized
|
private static java.sql.ResultSetMetaData |
metadata
|
private java.lang.String |
schemaName
|
private SpaceInfo |
spaceInfo
|
private java.lang.String |
tableName
|
private TransactionController |
tc
|
private boolean |
wasNull
|
Fields inherited from interface org.apache.derby.vti.VTICosting |
defaultEstimatedCost, defaultEstimatedRowCount |
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 | |
SpaceTable(java.lang.String tableName)
|
|
SpaceTable(java.lang.String schemaName,
java.lang.String tableName)
|
Method Summary | |
void |
close()
|
private void |
getConglomInfo(LanguageConnectionContext lcc)
|
double |
getEstimatedCostPerInstantiation(VTIEnvironment vtiEnvironment)
Get the estimated cost for a single instantiation of a VTI. |
double |
getEstimatedRowCount(VTIEnvironment vtiEnvironment)
Get the estimated row count for a single scan of a VTI. |
int |
getInt(int columnNumber)
|
long |
getLong(int columnNumber)
|
java.sql.ResultSetMetaData |
getMetaData()
|
short |
getShort(int columnNumber)
|
private void |
getSpaceInfo(int index)
|
java.lang.String |
getString(int columnNumber)
|
boolean |
next()
|
boolean |
supportsMultipleInstantiations(VTIEnvironment vtiEnvironment)
Find out if the ResultSet of the VTI can be instantiated multiple times. |
boolean |
wasNull()
|
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
private ConglomInfo[] conglomTable
boolean initialized
int currentRow
private boolean wasNull
private java.lang.String schemaName
private java.lang.String tableName
private SpaceInfo spaceInfo
private TransactionController tc
private static final ResultColumnDescriptor[] columnInfo
private static final java.sql.ResultSetMetaData metadata
Constructor Detail |
public SpaceTable(java.lang.String schemaName, java.lang.String tableName)
public SpaceTable(java.lang.String tableName)
Method Detail |
private void getConglomInfo(LanguageConnectionContext lcc) throws StandardException
StandardException
private void getSpaceInfo(int index) throws StandardException
StandardException
public java.sql.ResultSetMetaData getMetaData()
getMetaData
in interface java.sql.ResultSet
ResultSet.getMetaData()
public boolean next() throws java.sql.SQLException
next
in interface java.sql.ResultSet
java.sql.SQLException
- if no transaction context can be foundResultSet.next()
public void close()
close
in interface java.sql.ResultSet
ResultSet.close()
public java.lang.String getString(int columnNumber)
getString
in interface java.sql.ResultSet
getString
in class VTITemplate
ResultSet.getString(int)
public long getLong(int columnNumber)
getLong
in interface java.sql.ResultSet
getLong
in class VTITemplate
ResultSet.getLong(int)
public short getShort(int columnNumber)
getShort
in interface java.sql.ResultSet
getShort
in class VTITemplate
ResultSet.getShort(int)
public int getInt(int columnNumber)
getInt
in interface java.sql.ResultSet
getInt
in class VTITemplate
ResultSet.getInt(int)
public boolean wasNull()
wasNull
in interface java.sql.ResultSet
wasNull
in class VTITemplate
ResultSet.wasNull()
public double getEstimatedRowCount(VTIEnvironment vtiEnvironment)
VTICosting
getEstimatedRowCount
in interface VTICosting
vtiEnvironment
- The VTIEnvironment.
VTICosting.getEstimatedRowCount(org.apache.derby.vti.VTIEnvironment)
public double getEstimatedCostPerInstantiation(VTIEnvironment vtiEnvironment)
VTICosting
getEstimatedCostPerInstantiation
in interface VTICosting
vtiEnvironment
- The VTIEnvironment.
VTICosting.getEstimatedCostPerInstantiation(org.apache.derby.vti.VTIEnvironment)
public boolean supportsMultipleInstantiations(VTIEnvironment vtiEnvironment)
VTICosting
supportsMultipleInstantiations
in interface VTICosting
vtiEnvironment
- The VTIEnvironment.
VTICosting.supportsMultipleInstantiations(org.apache.derby.vti.VTIEnvironment)
|
Built on Tue 2006-10-10 19:23:47+0200, from revision exported | |||||||||
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