Exam 70-764 topic 1 question 251 discussion

Actual exam question from Microsoft's 70-764

Question #: 251
Topic #: 1

You are the new database administrator for a SQL Server 2014 instance.
You conduct an assessment on the instance and determine that the auto create statistics setting on the database named DB1 has been turned off.
You see no evidence that any maintenance has been occurring. You want to set up monitoring to see if query performance is being affected. You need to set up a monitoring process that will capture any cases where statistics could have been useful if they existed.
What should you do?

A. Create a SQL Server Agent job to execute DBCC SHOWSTATISTICS on each of the primary key columns in the database.
B. Use the missing_column_statistics extended event.
C. Query the sys.statistics system view to see all cases where the statistics were last needed.
D. Write a query using the sys.dm_db_missing_index_group_stats DMV Joining to sys.indexes, filtering on is_hypothetical.

Show Suggested Answer

Suggested Answer: B 🗳️
The Missing Column Statistics event class indicates that column statistics that could have been useful for the optimizer are not available. By monitoring the
Missing Column Statistics event class, you can determine if there are statistics missing for a column used by a query.
This can cause the optimizer to choose a less efficient query plan than expected.

by TheSwedishGuy at Jan. 31, 2020, 2:20 p.m.

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TheSwedishGuy

5 years, 5 months ago

The Missing Column Statistics event class indicates that column statistics that could have been useful for the optimizer are not available. https://docs.microsoft.com/en-us/sql/relational-databases/event-classes/missing-column-statistics-event-class?view=sql-server-ver15

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