Transaction states in DBMS Theory - Step-by-Step Execution

Concept Flow - Transaction states

Start Transaction

↓

Active State

↓

Decision: Commit or Rollback?

↓

Partially Committed

↓

Committed

↓

End Transaction

A transaction starts active, then either commits or aborts, passing through intermediate states before ending.

Execution Sample

DBMS Theory

BEGIN TRANSACTION;
-- perform operations
COMMIT;

Starts a transaction, performs operations, then commits to save changes.

Analysis Table

Step	Transaction State	Action	Result
1	Start	Begin transaction	Transaction is active
2	Active	Perform operations	Operations executed
3	Active	Decide to commit	Move to partially committed
4	Partially Committed	Commit changes	Changes saved, move to committed
5	Committed	End transaction	Transaction ends successfully

💡 Transaction ends after commit; all changes are saved permanently.

State Tracker

Transaction State	Start	After Step 2	After Step 3	After Step 4	Final
State	Start	Active	Partially Committed	Committed	End

Key Insights - 2 Insights

Why is there a 'Partially Committed' state before 'Committed'?

The 'Partially Committed' state means all operations are done but changes are not yet permanent; this is shown in execution_table step 3 and 4.

What happens if a failure occurs during the 'Active' state?

If failure occurs, the transaction moves to 'Failed' then 'Aborted' state, rolling back changes, which is not shown here but is a common alternate path.

Visual Quiz - 3 Questions

Look at the execution_table at step 3, what is the transaction state?

A Partially Committed

B Committed

C Active

D Failed

💡 Hint

Refer to the 'Transaction State' column at step 3 in execution_table.

At which step does the transaction end successfully?

A Step 5

B Step 2

C Step 3

D Step 4

💡 Hint

Check the 'Result' column for when the transaction ends in execution_table.

If the transaction fails during operations, which state would it enter next?

A Committed

B Aborted

C Partially Committed

D Active

💡 Hint

Recall the concept_flow shows failure leads to 'Aborted' state.

Concept Snapshot

Transaction states flow from Start -> Active -> (Commit or Rollback) -> End.
Active means operations are running.
Partially Committed means operations done but not saved.
Committed means changes saved permanently.
Failed and Aborted mean rollback due to error.
Transaction ends after commit or abort.

Full Transcript

A transaction in a database management system goes through several states. It starts with the 'Start' state when the transaction begins. Then it moves to 'Active' while operations are performed. After operations, if the transaction is successful, it moves to 'Partially Committed' where all operations are done but changes are not yet permanent. Then it moves to 'Committed' where changes are saved permanently. Finally, the transaction ends successfully. If an error occurs during 'Active', the transaction moves to 'Failed' and then 'Aborted', rolling back changes and ending the transaction without saving. This flow ensures data integrity and consistency.