Question

Why are there long extract times? 

Environment

Connector: PostgresSQL Database

Answer

The best solution is to add a primary key to the table. You can do this by running this query:

ALTER TABLE table_name ADD PRIMARY KEY (column_1, column_2);

If this is a partition table, the primary key should be globally-unique. 

Cause

Without a primary key, Fivetran will be forced to read the entire table every time. If your table does not have a primary key it can result in performance issues. This includes long table extract times.