When most but not all rows in the table have the same value
for a property, the column values are skewed. Property skew might
cause a query not to use a database index.
Because of skew for Property1, for example, a query execution plan
might not use the database index on that property in the following
query:
SELECT Id
FROM Document
WHERE Property1 = 'value'
Whether the index is used depends on the following circumstances:
- The statistics and configuration that is available in the database
- The value that is searched on when the query execution plan is
cached