I have some set of tables which has 20 million records in a postgres server. As of now i m migrating some table data from one server to another server using insert and update queries with dependent tables in functions. It takes around 2 hours even after optimizing the query. I need a solution to migrate the data faster by using mongodb or cassandra. How?
Try putting your updates and inserts into a file and then load the file. I understand Postgresql will optimise loading the file contents. It's always worked for me although I haven't used that quantity.