# Practical choices

These guides help choose value contracts and input paths for an application. Start with the data the application must accept, then verify the exact SQL behavior in the reference.

## Guides

* [Choose a primary key](https://coordinatordb.com/docs/concepts/best-practices/choosing-a-primary-key)

* [Choose JSON declarations](https://coordinatordb.com/docs/concepts/best-practices/json-type)

* [Choose a data type](https://coordinatordb.com/docs/concepts/best-practices/select-data-type)

* [Choose an insert method](https://coordinatordb.com/docs/concepts/best-practices/selecting-an-insert-strategy)

* [Check joins](https://coordinatordb.com/docs/concepts/best-practices/minimize-optimize-joins)