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Thread: Is possible to reduce the input buffer of a step?

  1. #1
    Join Date
    Jul 2007

    Default Is possible to reduce the input buffer of a step?

    I was wondering if it is possible to reduce the input buffer of a step?

    The background of this requirement is the following: I generate SQL queries dynamically from the data dictionary. Some of those - let's call them dimension tables - have only a couple of rows and take seconds to execute. Others - the fact tables - take hours.

    The queries themselves are executed biz a database lookup step that runs with 3 instances. Now it can happen is that the queries are distributed very unfortunately, e.g. that two steps receive only dimension queries and the third gets all fact tables. Once the dimension queries are done the two steps will shout down since the other fact tables are in the input buffer of the third step.

    So to solve that problem I would like all the queries to remain in the output buffer of the step that generates the and only to be forwarded once a step is idle to ensure all steps work as long in parallel as possible. Is that possible?

  2. #2
    Join Date
    Nov 1999


    You can configure the Row Set size in the transformation settings dialog, the misc tab.
    Alternatively you can try to enable the blocking batching row set by setting the corresponding variable in the kettle properties file (use the editor).
    That one only keeps a few rows as a buffer.

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