Informatica INTERVIEW QUESTION & ANSWERS
| 36. |
What is the diffrence between OLTP and OLAP? |
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The main differences between OLTP and OLAP are:
- OLTP systems are for doing clerical/operational processing of data whereas OLAP systems are for carrying out analytical processing of the data.
- OLTP systems look at data in one dimension; whereas in OLAP systems, data can be viewed in different dimensions and hence interesting business intelligence can be extracted from the data.
- Operational personnel of an organization use the OLTP systems whereas management uses OLAP systems, though operational personnel may also use portions of OLAP system.
- OLTP systems contain the current data as well as the details of the transactions. OLAP systems contain historical data, and also data in summarized form.
- OLTP database size is smaller as compared to OLAP systems. If the OLTP database occupies Gigabytes (GB) of storage space, OLAP database occupies Terabytes (TB) of storage space.
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| 37. |
What is DTM? |
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DTM transform data received from reader buffer and its moves transformation to transformation on row by row basis and it uses transformation caches when necessary. |
| 38. |
What is meant by spatial data warehouse? |
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A data warehouse that manipulates spatial data, thus allowing spatial analysis. This is to be contrasted with conventional and temporal data warehouses. |
| 39. |
What is a Batch? |
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Batches provide a way to group sessions for either serial or parallel execution by the Informatica Server. |
| 40. |
What are the types of batch? |
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There are two types of batches are : - Sequential batch : Runs sessions one after the other.
- Concurrent batch : Runs sessions at the same time.
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