ALTER TABLE alters the definition of an existing table. It uses this basic syntax: ALTER TABLE name { action [, … ] | RENAME TO new_name | RENAME [ COLUMN ] column_name TO new_column_name | RENAME CONSTRAINT constraint_name TO new_constraint_name … Continued

Indexes speed up searches for data. While they are very effective at doing this, they also represent an extra operation when inserting, updating and deleting data, since every table update also requires an update of the index. Sequential Access To … Continued