The customer table contains 9.5 million records. The column customer_idis a primary key. The database Oracle.
Questions:
1) If the table contains the main sections or subsections? How do i decide? Also, I don't think that indexing columnA or columnB will help here because of the data type.
TableA.columnA (varchar) has more than 80% of the records for columnA values 5,6,7. The columnA has values from 1 to 7 only.
TableA.columnB (varchar) has 90% of the records for columnB value = 102. The columnB has values from 1 to 999.
In addition, typical queries (in a specific order):
Query1: where tableA.columnA = values
Query2: where tableA.columnB = values
Query3: where tableA.columnA = values AND/OR tableA.columnB = values
2) When we create subsections, what happens if the query contains only the where clause for the sub-size column? Is the query being executed directly in the subsection or through the main section?
3) the connection contains tableA.partitioned_column = tableB.indexed_column
(eg. customer_Table.branch_code = branch_table.branch_code)
Does markup help in case of JOIN? Will performance improve?