Slowing Down?

30 GB !!? Yikes!
Optimizing a DB remains a thing after all these years. There are a few operations you can do through the phpMyAdmin app, which is typically accessed through your hosting account. In the app, navigate to your DB and any table that has significant data such as the posts table. Go to the Operations tab. Under table maintenance you’ll find options to possibly improve table performance. Unless you frequently update and remove data, these operations may not yield noticeable results. If you’ve simply been adding more data, a little at a time over the years, there may not be much that can be optimized.

If that doesn’t help, it may be beneficial to implement some sort of caching scheme for your site so at least frequently requested pages can be served quickly without long time consuming DB queries. Unusual archive queries for posts from December 2007 are still going to be slow.

In some cases a better indexing schema can be helpful, but if the issue is just the large volume of posts, the default index schema is likely as good as it gets.

If none of that helps and reducing the size of your DB is out of the question, your only recourse might be to invest in a more powerful DB setup. I’m not suggesting that you actually delete data to reduce the size; rather that older, little used data be offloaded into a different DB or custom table. You’ll get faster queries for recent data at the expense of even slower queries for older data.