Custom Fields and performance

My question : how many custom fields or even taxonomies WordPress can handle without affecting performance?

The reason I ask, is because I started building a custom theme and I might need to have around 10 to 20 custom fields, and thinking if this will affect the speed of the site.

I understand that speed also depends on server/hosting and number of visits, cache techniques, etc…

I also expect that a post with one custom field will be faster then one post with ten custom fields.

But, let’s say a site that haves around 10,000 visits a day with a post with one custom field will the speed difference be much more different from a site with the same 10 000 visits a day with a post with 10 custom fields.

Just trying to figure it out how much of a difference a custom field can make.

Also in terms of custom searching using wp_query and custom fields parameters will the speed be affected.

Thank you.

In the case of custom fields- if you fetch them in a single query to the database, fetching one or ten is not going to differ much, it’s the same relatively simple query in both instances. If you were to do a lot of complex meta queries on those fields you’d definitely see a performance hit.

I think same for taxonomy, if you’re doing complex taxonomy queries, that’s a big hit. Simple queries to fetch terms are relatively cheap.

Searching will certainly tax the server more if you’ve got ten times as much data, text searches are pretty expensive.