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How does SSDT handle batching of Data Flow tasks?

I am parsing a CSV that is about 1GB into SQL Server using SSDT.

In the Data Flow there is a Flat File source, that goes to an OLE DB destination (a staging table). Then an SP is executed using a SQL Task.

The CSV being parsed contains a summary table and a child table with a foreign key reference to the summary table. As such the CSV contains duplicated IDs of the summary table (so there is one line per child row). If a single summary ID were to be split across two batches, then I would lose data - the SP does something like "delete from child table where ID in staging, then re-insert from staging into child table". Previously we had to do this because the vendor wasn't exporting a unique ID for the child data. They are now, so I can use a merge statement.

But. I would still like to know if Data Flow tasks are batched, and if so, how?

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    Do you mean SSIS? SSDT is just an IDE. A Data Flow has a default buffer of 10k. References here.
    – Marian
    Feb 14, 2018 at 10:07

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As mentioned in the comment under the question, an answer to this question is included this post: http://blogs.lobsterpot.com.au/2011/02/17/the-ssis-tuning-tip-that-everyone-misses/

That is, that batching is done by default (10k rows per batch).

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