org.apache.derby.diag

Class ErrorLogReader

java.lang.Object

org.apache.derby.vti.VTITemplate

org.apache.derby.diag.ErrorLogReader

All Implemented Interfaces:

java.lang.AutoCloseable, java.sql.ResultSet, java.sql.Wrapper, AwareVTI

public class ErrorLogReader
extends VTITemplate

ErrorLogReader is a virtual table interface (VTI) which contains all the statements of "interest" in db2j.log or a specified file when db2j.language.logStatementText=true.

One use of this VTI is to determine the active transactions and the SQL statements in those transactions at a given point in time, say when a deadlock or lock timeout occurred. In order to do that, you must first find the timestamp (timestampConstant) of interest in the error log. The SQL to view the active transactions at a given in time is:

SELECT vti.ts, threadid, cast(xid as int) as xid_int, cast(lccid as int) as lccid_int, logtext 
                 FROM new org.apache.derby.diag.ErrorLogReader() vti, 
                        (VALUES timestampConstant) t(ts)
                 WHERE vti.ts <= t.ts AND 
                                vti.ts >
                                        (SELECT MAX(ts) IS NULL ? '2000-01-01 00:00:00.1' : MAX(ts)
                                         FROM new org.apache.derby.diag.ErrorLogReader() vti_i
                                         WHERE (logtext LIKE 'Committing%' OR
                                                        logtext LIKE 'Rolling%') AND
                                                   vti.xid = vti_i.xid AND ts < t.ts)
                 ORDER BY xid_int, vti.ts
        

The ErrorLogReader virtual table has the following columns:

• TS varchar(26) - the timestamp of the statement.
• THREADID varchar(40) - the thread name.
• XID varchar(15) - the transaction ID.
• LCCID varchar(15) - the connection ID.
• DATABASE varchar(128) - Database name
• DRDAID varchar(50) - nullable. DRDA ID for network server session.
• LOGTEXT long varchar - text of the statement or commit or rollback.

Nested Class Summary

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

VTITemplate.ColumnDescriptor

Field Summary

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 and Description
ErrorLogReader() ErrorLogReader() accesses the derby.log in derby.system.home, if set, otherwise it looks in the current directory.
ErrorLogReader(java.lang.String inputFileName)

Method Summary

Modifier and Type	Method and Description
void	close()
java.sql.ResultSetMetaData	getMetaData()
java.lang.String	getString(int columnNumber) All columns in the Db2jLogReader VTI have a of String type.
boolean	next()
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, 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, getTimestamp, getType, getUnicodeStream, getUnicodeStream, getURL, getURL, getWarnings, insertRow, isAfterLast, isBeforeFirst, isClosed, isFirst, isLast, isWrapperFor, last, moveToCurrentRow, moveToInsertRow, 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

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

Methods inherited from interface java.sql.ResultSet

updateObject, updateObject, updateObject, updateObject

Constructor Detail

ErrorLogReader

public ErrorLogReader()
               throws StandardException

ErrorLogReader() accesses the derby.log in derby.system.home, if set, otherwise it looks in the current directory. ErrorLogReader('filename') will access the specified file name.

Throws:

StandardException

ErrorLogReader

public ErrorLogReader(java.lang.String inputFileName)
               throws StandardException

Throws:

StandardException

Method Detail

getMetaData

public java.sql.ResultSetMetaData getMetaData()

Specified by:

getMetaData in interface java.sql.ResultSet

Overrides:

getMetaData in class VTITemplate

See Also:

ResultSet.getMetaData()

next

public boolean next()
             throws java.sql.SQLException

Throws:

java.sql.SQLException - If database-access error occurs.

See Also:

ResultSet.next()

close

public void close()

See Also:

ResultSet.close()

getString

public java.lang.String getString(int columnNumber)
                           throws java.sql.SQLException

All columns in the Db2jLogReader VTI have a of String type.

Specified by:

getString in interface java.sql.ResultSet

Overrides:

getString in class VTITemplate

Throws:

java.sql.SQLException - If database-access error occurs.

See Also:

ResultSet.getString(int)

wasNull

public boolean wasNull()

Specified by:

wasNull in interface java.sql.ResultSet

Overrides:

wasNull in class VTITemplate

See Also:

ResultSet.wasNull()