We have a new query, with a where-clause:

where a < b (a & b are date fields)
and c = 0 (c can have values from 0 to 270)
and d = "2" (d can have 4 different values)


What is the best way to write this where clause, and which are the best
indexes to use ?

The table has a total of 32 million records.




My own thoughts were:

where d = "2" (get rid of most of the records)
and c = 0 (reduce the above subset to about 25%)
and a < b (leave the sequential scan for this remaining data
set)


And create indexes on c & d (which brings up another question -
composite or stand alone ?)



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