SQL Server Execution Plans - Red Gate Software

Chapter 5: Controlling Execution Plans with Hints
This results in the mismatched set of query plans in Figure 5.24.
Figure 5.24
Note that the second query is now using our IX_SalesOrderHeader_SalesPersonID
index, which resulted in a slightly longer execution time, but only 409 reads compared to
the 686 of the original query.
ROBUST PLAN
This query hint is used when you need to work with very wide rows. For example:
• a row that contains one or more variable length columns set to very large size or
even the MAX size introduced in 2005
• a row that contains one or more large objects (LOB) such as BINARY, XML or TEXT
data types.
Sometimes, when processing these rows, it's possible for some operators to encounter
errors, usually when creating worktables as part of the plan. The ROBUST PLAN hint
ensures that a plan that could cause errors won't be chosen by the optimizer.
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