You can create optimal indexes by paying attention to the data type of the indexed column and by minimizing the number of duplicate values in the column. The more frequently a particular value occurs, the less efficient that column becomes as an indexed column.
The fastest, most efficient data types for indexed access are INTEGER, REAL, DATE, TIME, and TEXT with a defined length of four characters or less.
You may find that indexing a table with 1500 or fewer rows actually increases the total time to search for rows of data, since the task also includes the time it takes to build the index.
