I have a table with a lot of columns. In a particular query being generated by a web API it selects 23 columns of data. With 4 of those columns in the where clause.
I am assuming that in order to avoid any bookmark lookups that I would need to create an index on the most selective column and then include the remaining 22 columns as included columns. Is this the correct approach? I ask because in my testing the only way I have avoided RID lookups is by including all the columns as included columns and the primary index being on a very selective column.
Any pointers, gotcha's and assistance is very much appreciated.
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