How to Reset Sequence in PostgreSQL

Disclaimer/Disclosure: Some of the content was synthetically produced using various Generative AI (artificial intelligence) tools; so, there may be inaccuracies or misleading information present in the video. Please consider this before relying on the content to make any decisions or take any actions etc. If you still have any concerns, please feel free to write them in a comment. Thank you.
---

Summary: Learn how to reset sequences in PostgreSQL databases to manage auto-incrementing columns effectively. Sequences are commonly used for generating unique identifiers, and resetting them can be necessary in various scenarios such as data maintenance or testing.
---

In PostgreSQL, sequences are often used to generate unique identifiers for columns, especially primary keys. However, there are times when you might need to reset a sequence, perhaps due to data maintenance tasks or testing scenarios. Resetting a sequence involves setting its current value to a specified value or to its default starting value. Here's how you can reset a sequence in PostgreSQL:

Resetting Sequence to a Specific Value

To reset a sequence to a specific value, you can use the ALTER SEQUENCE command followed by the RESTART WITH option:

[[See Video to Reveal this Text or Code Snippet]]

Replace sequence_name with the name of the sequence you want to reset and new_value with the desired starting value for the sequence.

For example, to reset a sequence named my_sequence to start from 100:

[[See Video to Reveal this Text or Code Snippet]]

Resetting Sequence to its Default Starting Value

If you want to reset a sequence to its default starting value (usually 1), you can use the RESTART option without specifying a new value:

[[See Video to Reveal this Text or Code Snippet]]

This command sets the sequence back to its default starting value.

Example

Let's say you have a table named users with an auto-incrementing primary key column called user_id, and its associated sequence is user_id_seq. If you want to reset the sequence to start from 1:

[[See Video to Reveal this Text or Code Snippet]]

This command resets the user_id_seq sequence to its default starting value, which is typically 1.

Caution

When resetting sequences, be cautious, especially in production environments. Resetting a sequence can affect data integrity if not done carefully. Ensure that you understand the implications of resetting a sequence, particularly if it's associated with primary key columns in your database.

Resetting sequences in PostgreSQL can be a useful tool for managing auto-incrementing columns and maintaining data integrity. Whether you need to reset a sequence to a specific value or its default starting value, PostgreSQL provides the necessary commands to accomplish this task efficiently.