Incremental strategies (append, merge, delete+insert) in dbt - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the append incremental strategy in dbt?

The append strategy adds new rows to an existing table without changing or removing existing data. It is like adding new pages to a notebook without erasing old pages.

intermediate

Explain the merge incremental strategy in dbt.

Merge updates existing rows if they match a key and inserts new rows if they don't exist. Think of it as updating your contact list: change info if contact exists, add new contact if not.

intermediate

What does the delete+insert incremental strategy do?

Delete+insert removes rows that match certain conditions and then inserts fresh data. It's like erasing a page in your notebook and rewriting it with updated notes.

beginner

Why use incremental strategies in dbt?

Incremental strategies save time and resources by only processing new or changed data instead of rebuilding entire tables every time.

beginner

Which incremental strategy would you use if you want to keep all old data and just add new rows?

You would use the append strategy because it only adds new rows without changing existing data.

Which incremental strategy updates existing rows and adds new rows in dbt?

A Merge

B Append

C Delete+Insert

D Full Refresh

Merge updates rows that match and inserts new rows if they don't exist.

What does the append strategy do in dbt?

A Deletes old rows and inserts new ones

B Updates existing rows only

C Adds new rows without changing existing data

D Rebuilds the entire table

Append only adds new rows, leaving existing data unchanged.

When would you use delete+insert strategy?

A When you want to append only

B When you want to update some rows and add new ones

C When you want to keep all old data

D When you want to remove certain rows and replace them with fresh data

Delete+insert removes specific rows and inserts updated data.

Which strategy is best to save time by processing only new or changed data?

A Incremental Strategies

B Full Refresh

C Manual Table Drop

D Append Only

Incremental strategies process only new or changed data, saving time.

In dbt, what key concept helps identify rows to update or delete in incremental models?

A Index

B Primary Key

C Foreign Key

D Partition

Primary key uniquely identifies rows for update or delete operations.

Describe the differences between append, merge, and delete+insert incremental strategies in dbt.

Think about how each strategy handles existing data and new data.

Explain why incremental strategies are useful in data transformation workflows.

Consider the cost of processing large datasets repeatedly.