DP-900 Describe core data concepts Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  OLTP and OLAP

  Why this is correct

  OLTP and OLAP are the two standard workload categories in data processing. OLTP systems handle high-volume, low-latency transactional operations such as order entry and inventory updates, emphasizing ACID guarantees and row-level integrity. OLAP systems support analytical queries that aggregate and summarize large historical datasets, often using columnar storage and multidimensional schemas for business intelligence. Together they capture the fundamental divide between running day-to-day operations and analyzing those operations afterward.

• ✗

  Batch processing and real-time processing

  Why it's wrong here

  Batch processing and real-time processing refer to when data is handled, representing latency and scheduling patterns rather than workload categories. OLTP is often conflated with real-time because transactions are immediate, but OLTP can also use queued or batched writes; OLAP can power real-time dashboards via streaming ingestion even though it is fundamentally analytical. The standard classification for order-taking versus reporting analyzes OLTP and OLAP. Therefore, focusing solely on timing misses the distinction between transactional and analytical purposes.

  When this WOULD be correct

  This option would be correct if the question asked: 'A company processes incoming sensor data continuously and also runs a nightly job to aggregate historical data. Which terms describe the processing methods?' In that case, the continuous processing is real-time and the nightly job is batch processing.

• ✗

  Relational and non-relational

  Why it's wrong here

  Relational and non-relational describe how data is stored and organized, not how it is processed. Relational models enforce fixed schemas with tables, keys, and SQL, while non-relational models use flexible documents, key-value pairs, or graphs. These storage paradigms can serve either OLTP or OLAP workloads, so they answer a different question than the one posed about workload types. Thus they are an incorrect pairing for classifying the company's processing needs.

  When this WOULD be correct

  A question that asks: 'A company stores customer orders in a SQL database and social media posts in a NoSQL database. Which terms describe these two data storage approaches?'

• ✗

  Structured and semi-structured

  Why it's wrong here

  Structured and semi-structured classify data formats: structured data fits neatly into rows and columns with a predefined schema, while semi-structured data like JSON or XML has flexible tags and nested hierarchies. These format types are orthogonal to workload type, as both OLTP and OLAP can consume structured or semi-structured data. Using them to answer the question confuses storage format with processing purpose, so it is not a valid characterization of the company's online order system.

  When this WOULD be correct

  This option would be correct in a question like: 'A company stores customer records in a fixed-schema SQL database and also stores JSON logs from web servers. Which terms describe these two data formats?'

Option-by-option analysis

Why each answer is right or wrong

Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The DP-900 exam frequently reuses these exact scenarios with slightly different constraints.

Analysis generated from the official DP-900blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”

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