Type (Index Keyword)
Specifies the type of index.
To specify the type of the index, use the following syntax:
Index name On property_expression_list [ Type = indextype ];
name is the name of the index. It is useful to follow a naming convention so that indexes can be easily distinguished from properties. For example, you could include IDX at the end of all index names.
property_expression_list is either a single property name or a comma-separated list of properties, enclosed in parentheses.
indextype is one of the following:
bitmap — a bitmap index
bitslice — a bitslice index
collatedkey — an index on the given property, using the collation of that property
columnar — a columnar index
index — a standard index (default)
key — deprecated
This keyword specifies the type of the index, specifically whether the index is implemented as standard index or one of several special indexes.
A bitmap index cannot be marked as unique.
If you omit this keyword, the index is a standard index.