I am using c#, backend is Mysql db.
I have 3 tables in db, 1st table has 1.5 lakh records, 2nd table has 1.75 lakh records and 3rd table has 21 lakh records. i need the output using above 3 tables, so i joined above 3 table using inner join and i got the output with 1.5 lakh records, but it takes 8 hours of time.
I used primary keys in joining tables, can anyone suggest me to increase the performance.
What I have tried:
select Col1, col2,...coln from table1
JOIN table2 on table1.Id = table2.Id
JOIN table3 on table1.Id = table3.Id