I have a problem in deciding on index. I have a table in mySQL say X with atlas 70 million records. I need to query few fields based on filter like Year = X and Quarter = X and ( user = X or manager = X or ..)
I have an index on year and quarter which is not considered. So if it is considered, then less than 10% of the data is used.
I have index on year, quarter and all the user fields. Even then the index is not considered.
What am I doing wrong?