A transactional system records transactions that encapsulate specific events that the organization wants to track.
Transactional systems are often high-volume, sometimes handling many millions of transactions in a single day. The data being processed has to be accessible very quickly. The work performed by transactional systems is often referred to as Online Transactional Processing (OLTP).
OLTP solutions rely on a database system in which data storage is optimized for both read and write operations in order to support transactional workloads in which data records are created, retrieved, updated, and deleted (often referred to as CRUD operations). These operations are applied transactionally, in a way that ensures the integrity of the data stored in the database.
OLTP systems enforce transactions that support so-called ACID semantics:
- Atomicity: each transaction is treated as a single unit, which succeeds completely or fails completely.
- Consistency: transactions can only take the data in the database from one valid state to another.
- Isolation: concurrent transactions cannot interfere with one another, and must result in a consistent database state.
- Durability: when a transaction has been committed, it will remain committed.
OLTP systems are typically used to support live applications that process business data often referred to as line of business (LOB) applications.