RE: Avoid KeyLookup – SQLServerCentral

SSC Guru

Points: 323504

January 29, 2014 at 6:33 am

the key lookup, just by itself, is not a bad thing.

the query is using the unique index, but has to lookup the other values (due to the SELECT *)

to do that, it does a key loookup of the clustered index to return the other columns of data(COMPONENT_ID,AMOUNT,START_DATE,END_DATE).

any query that is doing SELECT * would most likely have that kind of lookup;

if you were returning a specific subset of columns, you might add an index with an include of those columns.

Lowell

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