Details
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Improvement
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Status: Resolved
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Minor
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Resolution: Fixed
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1.9.0
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None
Description
Drill provides a mock data storage engine that generates random data. The mock engine is used in some older unit tests that need a volume of data, but that are not too particular about the details of the data.
The mock data source continues to have use even for modern tests. For example, the work in the external storage batch requires tests with varying amounts of data, but the exact form of the data is not important, just the quantity. For example, if we want to ensure that spilling happens at various trigger points, we need to read the right amount of data for that trigger.
The existing mock data source has two limitations:
1. It generates only "black/white" (alternating) values, which is awkward for use in sorting.
2. The mock generator is accessible only from a physical plan, but not from SQL queries.
This enhancement proposes to fix both limitations:
1. Generate a uniform, randomly distributed set of values.
2. Provide an encoding that lets a SQL query specify the data to be generated.
Example SQL query:
SELECT id_i, name_s50 FROM `mock`.employee_10K;
The above says to generate two fields: INTEGER (the "_i" suffix) and VARCHAR(50) (the "_s50") suffix; and to generate 10,000 rows (the "_10K" suffix on the table.)
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