Query plan on an Index Seek output a IsBaseRow1005

Dan Holmes 2014-09-05 15:20:14

what is that? I googled and didn't find a reference to this.

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Aaron Bertrand 2014-09-05 15:33:58
Looks like a column or column alias to me (see the output list).
Dan Holmes 2014-09-05 15:50:53
I don't have a column named that in that table nor is there an column alias on any column in the SQL named that.
SQLkiwi 2014-09-06 01:08:22
It is an internal flag, seen in data modification queries and some cursor plans. It helps keep track of what came from where. Update processing is extremely complex. You may also see this flag in plans with CASE and a subquery. Ultimately, it's all internal and nothing to be concerned about.
Dan Holmes 2014-09-06 13:55:53
Interesting. This is neither an update nor cursor. It does have many joins though.

thanks

Martin Smith 2017-09-16 11:41:06
Came across this page googling "IsBaseRow".

One other place I have seen this used is to avoid performing key lookups on rows that didn't match in an outer join.

A somewhat unfortunate example of that here https://stackoverflow.com/a/46253379/73226