Sample Exam Questions

From the objective of OSS-DB Exam Silver
S3.1 SQL commands (Datatypes)

Sample Question


Choose one incorrect description of the data type that handles JSON.

  1. The json and jsonb data types are available for storing JSON data.

  2. Because the json type simply stores a copy of the input value, multiple JSON objects may contain the same key and value.

  3. The jsonb type is much faster because it does not need to be reparsed each time it is processed.

  4. The json type supports indexes.

  5. he jsonpath type is provided to efficiently query the data that stores JSON.

※This sample exam is different from those that appear in the actual OSS-DB Exam.

Answer and Explanation

PostgreSQL provides the json and jsonb data types for storing JSON data, and the jsonpath type for efficient querying of these data types.
The json type stores input values as is, so JSON processing functions like references need to be reparsed each time they are executed.
The jsonb type stores data in an optimized binary format. While storing data can be slightly slower due to the overhead of conversion, executing JSON processing functions is significantly faster as no reparsing is needed.
Unless you have a special use case, it is recommended to use the jsonb type, which also supports indexes.

Since the question asks to choose the incorrect statement, the correct answer is D.

This is a question where you need to select the incorrect option, so the correct answer is D.