To schedule a pg_repack job using pg_cron on an Amazon RDS for PostgreSQL instance, you need to follow a few steps. However, it’s important to note that pg_cron is only supported on certain versions of Amazon RDS, and pg_repack is also a separate extension that must be installed and enabled.
Here’s a general guide on how you can set this up:
Prerequisites
- Check Compatibility: Ensure that your RDS instance supports pg_cron and pg_repack. Both extensions need to be available and supported by the RDS version you are using.
- Install pg_repack: Ensure pg_repack is installed on your RDS instance. You can install it via the AWS Management Console if it's available for your PostgreSQL version. For example:
- Go to RDS Dashboard -> Parameter Groups.
- Modify the parameter group associated with your RDS instance to add pg_repack to the shared_preload_libraries parameter.
- Enable pg_cron: Similarly, ensure that pg_cron is enabled. You may need to add pg_cron to the shared_preload_libraries in your parameter group and reboot your instance.
Setting Up the Job
- Create the pg_cron Extension: First, create the pg_cron extension in your database:
sql
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CREATE EXTENSION IF NOT EXISTS pg_cron;
- Create the pg_repack Extension: Similarly, create the pg_repack extension:
sql
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CREATE EXTENSION IF NOT EXISTS pg_repack;
- Schedule a pg_repack Job: You can schedule a job using pg_cron to run pg_repack. Here is an example of how to set up a weekly job:
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SELECT cron.schedule(
'weekly_repack',
'0 3 * * 0', -- This runs every Sunday at 3 AM
$$
SELECT pg_repack.repack_database();
$$);
In this example, pg_repack.repack_database() is called to reorganize the database. Adjust the schedule _expression_ (0 3 * * 0) as needed to fit your desired schedule.
Considerations
- Permissions: Ensure the user running the pg_cron job has the necessary permissions to execute pg_repack.
- Performance Impact: Running pg_repack can be resource-intensive. Schedule the job during off-peak hours to minimize the impact on your database.
- Testing: Before scheduling the job, test pg_repack on a non-production instance to ensure it behaves as expected.
- Monitoring: Monitor the job to ensure it completes successfully and troubleshoot any issues that arise.
By setting up pg_repack with pg_cron on Amazon RDS for PostgreSQL, you can automate the process of reclaiming disk space and improving database performance without significant downtime.
Thanks!
Jake
HiPlease share the details for pg_repack job schedule with pg_cron from RDS postgres database instance level.ThanksSathishreddy