bad performance and strange behavior when exporting a view

Details

Detail name Value
Changelog Number 5021
Type Bug
Status Resolved
Affected Versions EXASOL 6.0.0
Fix Versions EXASOL 6.0.4
Resolution Date 2017-09-12
Description

When exporting a view directly as source table of an EXPORT statement the view is not processed correctly by the query optimizer. This can lead to different effects:

  • bad performance
  • exceptions in query execution
  • internal server error

This bug only affects EXPORT statements with the view as direct source-table:

EXPORT <myview> INTO ...

If any of this things happen to an EXPORT statement, especially one that worked in EXASolution 5, use the workaround, please.

Workaround

Instead of exporting the view as direct source of the EXPORT-statement, you can export a SELECT of the whole view. That export statement will work correctly:

EXPORT (SELECT * FROM <myview>) INTO ...