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Class COM.cloudscape.vti.TransactionTable
java.lang.Object
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+----COM.cloudscape.vti.VTITemplate
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+----COM.cloudscape.vti.TransactionTable
- public class TransactionTable
- extends VTITemplate
- implements VTICosting
Copyright © 1998-2000, Informix Software, Inc. All rights reserved.
TransactionTable is a virtual table which shows all the transactions
currently in the database. This virtual table can be invoked by calling it
directly
select * from new COM.cloudscape.vti.TransactionTable() t;
or through the system alias TransactionTable
select * from new TransactionTable() t;
The TransactionTable virtual table takes a snap shot of the
transaction table while the system is in flux, so it is possible that some
transactions may be in transition state while the snap shot is taken.
We choose to do this rather then impose extraneous timing restrictions so
that the use of this tool will not alter the normal timing and flow of
execution in the application.
The TransactionTable virtual table has the following columns:
- XID varchar(10) - not nullable. The transaction id, this can be joined
with the LockTable virtual table's XID.
- GLOBAL_XID varchar(140) - nullable. The global transaction id, only
set if this transaction is a participant in a distributed transaction.
- USERNAME varchar(30) - nullable. The user name, or APP by default.
May appear null if the transaction is started by cloudscape.
- TYPE varchar(30) - not nullable. UserTransaction or an internal
transaction spawned by cloudscape.
- STATUS varchar(8) - not nullable. IDLE or ACTIVE. A transaction is
IDLE only when it is first created or right after it commits. Any
transaction that holds or has held any resource in the database is ACTIVE.
Accessing the TransactionTable virtual table without using the class alias
will not activate the transaction.
- FIRST_INSTANT varchar(20) - nullable. If null, this is a read only
transaction. If not null, this is the first log record instant written by
the transaction.
- SQL_TEXT varchar(1024) - nullable. if null, this transaction is
currently not being executed in the database. If not null, this is the SQL
statement currently being executed in the database.
TransactionTable()
-
close()
-
getEstimatedCostPerInstantiation(VTIEnvironment)
-
getEstimatedRowCount(VTIEnvironment)
-
getMetaData()
-
getString(int)
- All columns in TransactionTable VTI is of String type.
next()
-
supportsMultipleInstantiations(VTIEnvironment)
-
wasNull()
-
TransactionTable
public TransactionTable()
getMetaData
public java.sql.ResultSetMetaData getMetaData()
- See Also:
- getMetaData
next
public boolean next() throws java.sql.SQLException
- Throws:
- java.sql.SQLException - if no transaction context can be found
- See Also:
- next
close
public void close()
- See Also:
- close
getString
public java.lang.String getString(int columnNumber)
All columns in TransactionTable VTI is of String type.
- Overrides:
- getString in class VTITemplate
- See Also:
- getString
wasNull
public boolean wasNull()
- Overrides:
- wasNull in class VTITemplate
- See Also:
- wasNull
getEstimatedRowCount
public double getEstimatedRowCount(VTIEnvironment vtiEnvironment)
- See Also:
- getEstimatedRowCount
getEstimatedCostPerInstantiation
public double getEstimatedCostPerInstantiation(VTIEnvironment vtiEnvironment)
- See Also:
- getEstimatedCostPerInstantiation
supportsMultipleInstantiations
public boolean supportsMultipleInstantiations(VTIEnvironment vtiEnvironment)
- Returns:
- false
- See Also:
- supportsMultipleInstantiations
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