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From Fabian Hueske <fhue...@gmail.com>
Subject Re: [FLINK-3848] Add ProjectableTableSource
Date Wed, 02 Nov 2016 13:10:32 GMT
Hi Anton,

a regular TableSource does not accept a predicate and return the whole
table.
A ProjectableTableSource is able to evaluate a predicate while scanning.
TableSources that evaluate predicates while (or rather before) scanning can
significantly reduce IO compared to a full scan.

Sources that could be access with a ProjectableTableSource would be a JDBC
database which pushes a query to a JDBC connected database, a Parquet file,
or an ORC file.

Best, Fabian






2016-11-02 13:53 GMT+01:00 Anton Solovev <Anton_Solovev@epam.com>:

> Hi folks,
>
> Can you explain me what ProjectableTableSource is ?
> What is it being invented for?
>
> Best,
> Anton
>
>

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