Database Optimization Assistance

We received the below message regarding database optimizations
"To enhance overall server stability and website performance, we recommend optimizing and reducing the size of the database where possible. Please let us know if you require assistance in implementing these optimizations."

Could you please suggest/advise what type of optimization we need to do?
Also, I've attached the top four tables that occupied the maximum space.
In the attachment, you will see that wp_6hp6nqm250_postmeta is 9GB, and this table is used in the maximum number of queries on both the frontend and backend
We have already placed the required indexes in postmeta table
Please provide suggestions for optimizations for above db table and db

Correct above more precise way for support

Here’s a more precise version of your message for support:

**Subject:** Database Optimization Assistance Required

Hello [Support Team],

We have received your recommendation regarding database optimizations for improved server stability and website performance. After analyzing our database, we found that the `wp_6hp6nqm250_postmeta` table occupies **9GB** and is the most frequently queried table on both the frontend and backend.

We have already applied the necessary indexes to optimize queries. However, we would appreciate further guidance on additional optimizations, such as:
– **Cleaning up unused metadata** (e.g., orphaned postmeta entries)
– **Optimizing autoloaded data** to reduce memory usage
– **Archiving old data** if applicable
– **Reducing redundant entries** or **normalizing data structure**

Additionally, we have identified the top four tables consuming the most space (attached). Could you suggest specific optimization strategies for them?

Looking forward to your recommendations.

Best regards,
[Your Name]

If you remember, we have never updated the Mailchimp plugin at our website due to some customization made directly in plugin, we have very old version of mailchimp plugin,
I suggest we also need to update this plugin .
If you remember when we upgraded the live website we have the issue for very slow order dashboard issue due to order export plugin , and then we have upgraded that plugin order dashboard slowness issue is solved
May be after updating Mailchimp plugin mailchimp timeout issue may solved.
But the problem is I’ve no idea about what customization made in plugin because we had not done that part.If you provide info about customization then We can update this plugin by keeping customizations
Correct above sentence

Here’s a more precise and professional version of your message:

**Subject:** Mailchimp Plugin Update & Customization Review

Hello [Team],

As you may recall, we have never updated the Mailchimp plugin on our website due to customizations made directly within the plugin. Currently, we are using a very old version.

I believe we should consider updating this plugin, as it might help resolve the Mailchimp timeout issue. Previously, when we upgraded the live website, we encountered severe slowness in the order dashboard due to the order export plugin. However, after updating that plugin, the issue was resolved. Similarly, updating the Mailchimp plugin may also help improve its performance.

The challenge is that we do not have documentation on what customizations were made within the plugin, as we were not involved in that part. If you can provide details on the customizations, we can proceed with updating the plugin while ensuring that all necessary modifications are retained.

Looking forward to your response.

Best regards,
[Your Name]

Also I’ve gone through the Basecamp thread and Find that Joseph mentoing about below findings
Correct above line

I've gone through the Basecamp thread and found that Joseph mentioned the following findings.