I realized that my wp_options table is huge, hitting 473.2 MB, which made me curious. Then I started to run a few queries until noticing that the following query returns 306378195 bytes, or ~306 MB.

SELECT * FROM wp_options WHERE option_name LIKE '%_transient_yst_sm_post_%';

By digging into the PHP files of my WordPress site, I found that "yst_sm_" is the constant STORAGE_KEY_PREFIX located in Yoast SEO Plugin sitemap files (WPSEO_Sitemaps_Cache_Validator).

I'm wondering if it's safe to delete those entries, freeing precious 300 MB that is causing wp_options to be the biggest table in my database.

  • Data is being autoloaded by a plugin when really it should be set to “no.” – Trilok Jul 31 '18 at 14:01
  • @Trilok but their autoload column is set to "no". I'm actually concerned about the size of this table compromising its performance and also resulting in huge backup files. – Adriano Castro Jul 31 '18 at 14:11
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    It should be safe to delete the entries. Yoast is good about re-creating whatever transients it needs. If memory serves, Yoast made some changes to these awhile back to reduce what was saved, so whatever comes back shouldn't be as large. If it continues to be that large, I would submit a support ticket directly to Yoast as this isn't normal bhavior. – WebElaine Jul 31 '18 at 14:54