What is in doubt transaction?

The two-phase commit mechanism ensures that all nodes either commit or perform a rollback together. What happens if any of the three phases fails because of a system or network error? The transaction becomes in-doubt.

What is Indoubt transactions DB2?

An indoubt transaction is a global transaction that was left in an indoubt state. DB2® provides heuristic actions that database administrators can perform on indoubt transactions when the resource owner, such as the database administrator, cannot wait for the Transaction Manager to perform the resync action.

In which phase the resource manager settle whether the transaction can be committed or rollback?

PREPARE phase
The PREPARE phase, in which the resource manager writes the log pages to disk, so that it can respond to either a COMMIT or a ROLLBACK primitive. The COMMIT (or ROLLBACK) phase, in which the transaction is actually committed or rolled back.

What are the commands used for transaction control processing?

The following commands are used to control transactions.

  • COMMIT − to save the changes.
  • ROLLBACK − to roll back the changes.
  • SAVEPOINT − creates points within the groups of transactions in which to ROLLBACK.
  • SET TRANSACTION − Places a name on a transaction.

Does ROLLBACK end transaction?

A transaction ends when it is committed or rolled back, either explicitly with a COMMIT or ROLLBACK statement or implicitly when a DDL statement is issued.

Are DML commands Autocommit?

No. Only the DDL(Data Definition Language )statements like create,alter,drop,truncate are auto commit.

Which are TCL commands?

Transaction Control Language commands are used to manage transactions in the database. Transactional control commands are used only DML Commands such as INSERT, UPDATE and DELETE. COMMIT, ROLLBACK and SAVEPOINT are the TCL commands used in SQL.

What does the DB2 UDB command line processor do?

The Db2 UDB command line processor (CLP) represents an interface through which you can conveniently access Db2 UDB functions. The CLP accepts commands or SQL statements from a Db2 command line.

How to exit interactive input mode in DB2?

To exit interactive input mode and return to the operating system prompt, issue the QUIT command or the TERMINATE command. Batch mode. This mode lets you run Db2 commands or SQL statements from a command script, a text file that contains the commands and statements in the order in which they are to be executed.

Which is better command line or front end for DB2?

But, if your command of SQL is strong — or you want to enter one quick command to verify the installation of DB2 — the command line is ideal, and usually faster that submitting similar requests through a front-end like PowerBuilder or Access. The CLP is a direct route to every DB2 programming interface.

Do you have to save DB2 command reference documents?

The DB2 Command Reference documents db2look. However, having the information saved up front in a file used to submit the DDL is more professional than hurriedly trying to recreate it when you’re in the middle of a new project that relies on another database’s schema. You don’t have to save all the DML (SELECTs, INSERTs, UPDATEs, DELETEs) in a file.