[CALCITE-1227] Add streaming CSV table

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.9.0
• Assignee: Julian Hyde
• Reporter: Julian Hyde
• Created: 04/May/16 16:01
• Updated: 27/Feb/24 22:23
• Resolved: 08/Jul/16 01:31

Description

Add a variant of CsvTable that can be streamed. It would serve as an example of how to write stream adapters.

It would be like the CSV adapter, but watches a file and reports records added to the end of the file (like the tail command).

You’d have to change CsvTable to implement StreamableTable, and implement the Table stream() method to return a variant of the table that is in “follow” mode.

It would probably be implemented by a variant of CsvEnumerator, but it is getting its input in bursts, as the file is appended to.

You would still be able to use this adapter to read historical data from the CSV file. Appending records to the file would make a nice demo.

Issue Links

• is depended upon by: CALCITE-1307 Further work on streaming CSV table
• is related to: CALCITE-849 Streams/Slow iterators dont close on statement close
• is related to: CALCITE-30 Implement Statement.cancel method
• is related to: CALCITE-884 File/web adapter
• relates to: CALCITE-872 Add support for aborting the query optimization process