In this recipe, we will be discussing a table reordering strategy based on an index, which will improve the query performance for a certain time.
In PostgreSQL, we have a utility command called
CLUSTER that is like
VACUUM. It will do some kind of table reorganization by acquiring access exclusive locks on the table. The
CLUSTER command will create a new physical table by aligning its pages in the order of the mentioned index. An advantage of doing this is to avoid the index lookup overhead during the index scan, since the table itself is in ordered. Another benefit of doing this is removing all dead tuples from the table and index.
CLUSTER command during the business hours is not recommended ...