Removing Columns from a data flow

Seems obvious but I can't see how. How would I remove columns from a data flow so that columns which have been used earlier but are not needed for insert/update are taken out of the flow.

I'm asking because the data ends up in a update statement and the flow has got so big it is unreadable.

Cheers, Al

You cannot remove a column from the buffer, the best method is to not create it to start with. Obviously starting from your source, only bring through the columns you need. Any asynchronous components, e.g. Aggregates, Sorts, Joins, can also be used to carefully select only the required columns. A new buffer is allocated for the output in the case of an asynchronous component, so the column selection can be done there. When the component is synchronous, changing the buffer structure would be a problem, as this would mean messing the what is designed to be a fast and efficient data transfer method, and messing with it during it's lifetime would presumably cost more than just carrying the data along. It would however be nice to hide columns at a meta-data level. Perhaps add it as a request in MSDN Feedback.

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Is there a way to remove columns in the UNION ALL component? My understanding is that it is an asynchronous component but I have not found a way to remove unneeded columns.

thanks

Peter

|||Once you have added the component, and added the inputs, you can open the UI for the Uion All. Now click on a row (for the column) to select it, then right-click and Delete. The column is now gone.