Package org.apache.derby.diag
Class SpaceTable
java.lang.Object
org.apache.derby.vti.VTITemplate
org.apache.derby.diag.SpaceTable
- All Implemented Interfaces:
AutoCloseable
,ResultSet
,Wrapper
,AwareVTI
,VTICosting
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 TABLE(SYSCS_DIAG.SPACE_TABLE('MYSCHEMA', 'MYTABLE')) T;If the schema name is not supplied, the default schema is used.
SELECT * FROM TABLE(SYSCS_DIAG.SPACE_TABLE('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:
- CONGLOMERATENAME varchar(128) - nullable. The name of the conglomerate, which is either the table name or the index name. (Unlike the SYSCONGLOMERATES column of the same name, table ID's do not appear here).
- ISINDEX SMALLINT - not nullable. Is not zero if the conglomerate is an index, 0 otherwise.
- NUMALLOCATEDPAGES bigint - not nullable. The number of pages actively linked into the table. The total number of pages in the file is the sum of NUMALLOCATEDPAGES + NUMFREEPAGES.
- NUMFREEPAGES bigint - not nullable. The number of free pages that belong to the table. When a new page is to be linked into the table the system will move a page from the NUMFREEPAGES list to the NUMALLOCATEDPAGES list. The total number of pages in the file is the sum of NUMALLOCATEDPAGES + NUMFREEPAGES.
- NUMUNFILLEDPAGES bigint - not nullable. The number of unfilled pages that belong to the table. Unfilled pages are allocated pages that are not completely full. Note that the number of unfilled pages is an estimate and is not exact. Running the same query twice can give different results on this column.
- PAGESIZE integer - not nullable. The size of the page in bytes for that conglomerate.
- ESTIMSPACESAVING bigint - not nullable. The estimated space which could possibly be saved by compressing the conglomerate, in bytes.
- TABLEID char(36) - not nullable. The UUID of the table.
To get space information on all schemas and tables, use a query such as
select v.* from SYS.SYSSCHEMAS s, SYS.SYSTABLES t, TABLE(SYSCS_DIAG.SPACE_TABLE(SCHEMANAME, TABLENAME)) v where s.SCHEMAID = t.SCHEMAID;
-
Nested Class Summary
Nested classes/interfaces inherited from class org.apache.derby.vti.VTITemplate
VTITemplate.ColumnDescriptor
-
Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final ResultColumnDescriptor[]
private ConglomInfo[]
(package private) int
(package private) boolean
private static final ResultSetMetaData
private String
private SpaceInfo
private String
private TransactionController
private boolean
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
Fields inherited from interface org.apache.derby.vti.VTICosting
defaultEstimatedCost, defaultEstimatedRowCount
-
Constructor Summary
ConstructorsConstructorDescriptionSpaceTable
(String tableName) SpaceTable
(String schemaName, String tableName) -
Method Summary
Modifier and TypeMethodDescriptionvoid
close()
private void
double
getEstimatedCostPerInstantiation
(VTIEnvironment vtiEnvironment) Get the estimated cost for a single instantiation of a Table Function.double
getEstimatedRowCount
(VTIEnvironment vtiEnvironment) Get the estimated row count for a single scan of a Table Function.int
getInt
(int columnNumber) long
getLong
(int columnNumber) short
getShort
(int columnNumber) private void
getSpaceInfo
(int index) getString
(int columnNumber) boolean
next()
boolean
supportsMultipleInstantiations
(VTIEnvironment vtiEnvironment) Find out if the ResultSet of the Table Function can be instantiated multiple times.boolean
wasNull()
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, getBoolean, getByte, getByte, getBytes, getBytes, getCharacterStream, getCharacterStream, getClob, getClob, getConcurrency, getContext, getCursorName, getDate, getDate, getDate, getDate, getDouble, getDouble, getFetchDirection, getFetchSize, getFloat, getFloat, getHoldability, getInt, getLong, getNCharacterStream, getNCharacterStream, getNClob, getNClob, getNString, getNString, getObject, getObject, getObject, getObject, getObject, getObject, getRef, getRef, getReturnTableSignature, getRow, getRowId, getRowId, getShort, getSQLXML, getSQLXML, getStatement, getString, getTime, getTime, getTime, getTime, getTimestamp, 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 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
-
Field Details
-
conglomTable
-
initialized
boolean initialized -
currentRow
int currentRow -
wasNull
private boolean wasNull -
schemaName
-
tableName
-
spaceInfo
-
tc
-
columnInfo
-
metadata
-
-
Constructor Details
-
SpaceTable
public SpaceTable() -
SpaceTable
-
SpaceTable
-
-
Method Details
-
getConglomInfo
- Throws:
StandardException
-
getSpaceInfo
- Throws:
StandardException
-
getMetaData
- Specified by:
getMetaData
in interfaceResultSet
- Overrides:
getMetaData
in classVTITemplate
- See Also:
-
next
- Specified by:
next
in interfaceResultSet
- Throws:
SQLException
- if no transaction context can be found- See Also:
-
close
public void close()- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceResultSet
- See Also:
-
getString
- Specified by:
getString
in interfaceResultSet
- Overrides:
getString
in classVTITemplate
- See Also:
-
getLong
public long getLong(int columnNumber) - Specified by:
getLong
in interfaceResultSet
- Overrides:
getLong
in classVTITemplate
- See Also:
-
getShort
public short getShort(int columnNumber) - Specified by:
getShort
in interfaceResultSet
- Overrides:
getShort
in classVTITemplate
- See Also:
-
getInt
public int getInt(int columnNumber) - Specified by:
getInt
in interfaceResultSet
- Overrides:
getInt
in classVTITemplate
- See Also:
-
wasNull
public boolean wasNull()- Specified by:
wasNull
in interfaceResultSet
- Overrides:
wasNull
in classVTITemplate
- See Also:
-
getEstimatedRowCount
Description copied from interface:VTICosting
Get the estimated row count for a single scan of a Table Function.- Specified by:
getEstimatedRowCount
in interfaceVTICosting
- Parameters:
vtiEnvironment
- The state variable for optimizing the Table Function.- Returns:
- The estimated row count for a single scan of the Table Function.
- See Also:
-
getEstimatedCostPerInstantiation
Description copied from interface:VTICosting
Get the estimated cost for a single instantiation of a Table Function.- Specified by:
getEstimatedCostPerInstantiation
in interfaceVTICosting
- Parameters:
vtiEnvironment
- The state variable for optimizing the Table Function.- Returns:
- The estimated cost for a single instantiation of the Table Function.
- See Also:
-
supportsMultipleInstantiations
Description copied from interface:VTICosting
Find out if the ResultSet of the Table Function can be instantiated multiple times.- Specified by:
supportsMultipleInstantiations
in interfaceVTICosting
- Parameters:
vtiEnvironment
- The state variable for optimizing the Table Function.- Returns:
- true
- See Also:
-