- Indexes should not be used on small tables.
- Indexes should not be used on columns that return a high percentage of data rows when used as a filter condition in a query’s WHERE clause.
- For instance, on a
status column that has enum-like string values such as 'ACTIVE' and 'DISABLED'.
- Indexes should not be used on columns that contain a high number of
NULL values. - This can be alleviated by using a partial index that omits those values.
- Indexes should not be used on columns that are frequently manipulated.
