Excel Reader: Parguet Table Storage Format

KNIME Analytics Platform
1

Hi,

when I use the current Excel Reader, I keep getting warnings that

Invalid storage format 'org.knime.parquet.ParquetTableStoreFormat' -- using standard KNIME table format instead

Is there anything I can to to make this warning disappear?

Thanks!

2

I think this warning appears if the workspace at some point was configured in the Preferences to use the “KNIME Column Storage (based on Apache Parquet)” for the row-based table backend (I know, the naming is confusing since we now since a few years have the “columnar table backend” (based on Arrow)).

You can either install that extension (I think it’s unlisted, so to find it you have to disable grouping by category), or what I would do if you don’t need to use that format (I don’t see a need to use it personally) would be to go to Preferences → KNIME → Table Backend and switch the backend to “Columnar Backend”, hit Apply, then switch back to “Row-based Backend” and hit Apply again. This should overwrite any settings that are there from the Parquet-based backend.

Let me know if that helps to remove the warning.

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3

Thank you @hotzm . Installing the extension solved the issue. I wasn’t aware, that it is unlisted and thought I had installed it in previous versions of KNIME.

Just for interest: is it still developed cause it’s not listed anymore or what is the reason for this? Thanks so much!

4

@hotzm
I’m a little bit confused now: You mention here that the extension is not maintained anymore?

So shall we still use it? If not, you’re above tip did not solve the issue.

Thanks for any hint.

5

Maybe I expressed it confusingly and the part with installing the extension was not helpful:

or what I would do if you don’t need to use that format (I don’t see a need to use it personally) would be to go to Preferences → KNIME → Table Backend and switch the backend to “Columnar Backend”, hit Apply, then switch back to “Row-based Backend” and hit Apply again. This should overwrite any settings that are there from the Parquet-based backend.

I understood you want to get rid of the warning and did not know whether you wanted to use the row-based on-disk format which uses Parquet under the hood or not. If you don’t then we just need your preferences to match what your installation (without this extension) can support: row-based with the KNIME on-disk format (aka. “Row-based Backend”) or Columnar (aka. “Columnar Backend”).

Hence, I think you need to switch in the preferences once to the “Columnar Backend”, get it to save, and switch back to the “Row-based Backend” and save.
Then the warning should disappear.

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