I have a question about type info, it looks like one in calcite mail you showed in jira, but I catch CodeGenException when checking predefined table field types with output types from source
Flink cannot generate conversion because of row arity. We cannot reduce number of table fields, but we can create a new code generation or let nulls come from CsvInputFormt Any ideas? -----Original Message----- From: Fabian Hueske [mailto:fhue...@gmail.com] Sent: Wednesday, November 2, 2016 5:11 PM To: dev@flink.apache.org Subject: Re: [FLINK-3848] Add ProjectableTableSource 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_solo...@epam.com>: > Hi folks, > > Can you explain me what ProjectableTableSource is ? > What is it being invented for? > > Best, > Anton > >
