Indexes, foreign keys, primary keys, and arrays are not supported in Redshift. The distribution key, which determines how your data is distributed across the cluster, is a very important part of the schema definition. Check all queries for the table and choose the column that gets joined most frequently for the distribution key to get the best performance. You can only specify one distribution key and if you are joining against multiple columns on a large scale, you might notice a performance degradation. Also, specify the columns your range queries use the most as sort key on your table (can be multi columns in sort key), as it will help with the performance.