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Drill, mail # user - Schema discovery


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Timothy Chen 2013-10-24, 18:05
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Re: Schema discovery
Julian Hyde 2013-11-01, 23:51
A recent blog post by Daniel Abadi has a similar theme:

http://hadapt.com/blog/2013/10/28/all-sql-on-hadoop-solutions-are-missing-the-point-of-hadoop/

We could create a tool that scans the raw files and generates an Optiq schema that contains views that apply "late schema" (the "EMP" and "DEPT" views in https://raw.github.com/apache/incubator-drill/HEAD/sqlparser/src/test/resources/test-models.json are examples of this). The user could interactively modify that schema (e.g. change a column's type from string to boolean or integer).

It's a nice approach because it doesn't impact the Drill engine. This is good. Metadata and data should be kept separate wherever possible.

Julian
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Timothy Chen 2013-11-02, 05:51