Acha Vala Essay

Q.1 OLTP vs. OLAP

We can divide IT systems into transactional (OLTP) and analytical (OLAP). In general we can assume that OLTP systems provide source data to data warehouses, whereas OLAP systems help to analyze it.
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- OLTP (On-line Transaction Processing) is characterized by a large number of short on-line transactions (INSERT, UPDATE, DELETE). The main emphasis for OLTP systems is put on very fast query processing, maintaining data integrity in multi-access environments and an effectiveness measured by number of transactions per second. In OLTP database there is detailed and current data, and schema used to store transactional databases is the entity model (usually 3NF).

- OLAP (On-line Analytical Processing) is characterized by relatively low volume of transactions. Queries are often very complex and involve aggregations. For OLAP systems a response time is an effectiveness measure. OLAP applications are widely used by Data Mining techniques. In OLAP database there is aggregated, historical data, stored in multi-dimensional schemas (usually star schema).

The following table summarizes the major differences between OLTP and OLAP system design.

| |OLTP System |OLAP System |
| |Online Transaction Processing |Online Analytical Processing |
| |(Operational System) |(Data Warehouse) |
|Source of data |Operational data; OLTPs are the original source |Consolidation data; OLAP data comes from the various |
| |of the data. |OLTP Databases |
|Purpose of data |To control and run fundamental business tasks |To help with planning, problem solving, and decision |
| |