Basics - A Historical Perspective
- File Systems v/s DBMS
- Data Models
- Levels of Abstraction
- Structure of DBMS
- Database Design
- Database Design
- ER Diagrams
- Attributes
- Entity
- Relationships
- Additional Features of the ER Model
- Relational Model
- Introduction to the Relational Model
- Integrity constraint over relations
- Enforcing Integrity Constraints
- Querying Relational Data
- Views
- Relational Algebra
- Tuple Relational Calculus
- SQL
- Form of basic SQL query
- UNION
- INTERSECT
- EXCEPT
- Aggregation Operators
- Complex Integrity Constraints in SQL
- Triggers and Active data bases
- Schema Refinement
- Problems caused by redundancy
- Decompositions and its problems
- Functional Dependencies and its reasoning
- Introduction to Normal Forms
- First Normal Form (1NF)
- Second Normal Form (2NF)
- Third Normal Form (3NF)
- Boyce-Codd Normal Form (BCNF)
- Fourth Normal Form (4NF)
- Fifth Normal Form (5NF or PJNF)
- Sixth Normal Form (6NF)
- Transaction
- Transaction Concept
- Transaction State
- Implementation of Atomicity and Durability
- Concurrent Executions
- Serializability
- Recoverability
- Implementation of Isolation
- Lock Based Protocols
- Timestamp Based Protocols
- Validation Based Protocols
- Multiple Granularity
- Recovery and Atomicity in dbms
- Recovery with Concurrent Transactions
- Indexing
- Data on External Storage
- File Organization and Indexing
- Cluster Indexes
- Primary Indexes
- Secondary Indexes
- Index data Structures
- Comparison of File Organizations, Indexes and Performance Tuning
- Indexed Sequential Access Methods
- Dynamic Index Structure - B+ Tree
Transaction State in DBMS
Each and every transactions in DBMS, pass through several states during their lifespan. These states, known as "Transaction States," collectively constitute the "Transaction Lifecycle." Here are the main states in the lifecycle of a transaction:
- Active: This is the initial state of every transaction. In this state, the transaction is being executed. The transaction remains in this state as long as it is executing SQL statements.
- Partially Committed: When a transaction executes its final statement, it is said to be in a 'partially committed' state. At this point, the transaction has passed the modification phase but has not yet been committed to the database. If a failure occurs at this stage, the transaction will roll back.
- Failed: If a transaction is in a 'partially committed' state and a problem occurs that prevents the transaction from committing, it is said to be in a 'failed' state. When a transaction is in a 'failed' state, it will trigger a rollback operation.
- Aborted: If a transaction is rolled back and the database is restored to its state before the transaction began, the transaction is said to be 'aborted.' After a transaction is aborted, it can be restarted again, but this depends on the policy of the transaction management component of the DBMS.
- Committed: When a transaction is in a 'partially committed' state and the commit operation is successful, it is said to be 'committed.' At this point, the transaction has completed its execution and all of its updates are permanently stored in the database.
- Terminated: After a transaction reaches the 'committed' or 'aborted' state, it is said to be 'terminated.' This is the final state of a transaction.
Note: The actual terms and the number of states may vary depending on the specifics of the DBMS and the transaction processing model it uses. However, the fundamental principles remain the same.
Next Topic :Implementation of Atomicity and Durability in DBMS