Did you know, it is not a good idea to start your permalink structure with the category, tag, author, or postname fields, why? It takes more time for WordPress to distinguish your Post URLs from Page URLs (which always use the text "page slug" as the URL), and to compensate, WordPress stores a lot of extra information in its database (so much that sites with lots of Pages have experienced difficulties.
This would be a problem for any dynamic CMS, not just WordPress. If there isn't some way to narrow down the information in the URL and map it to a specific page or post, the system must perform a lot of database searches to find the correct entry. Unfortunately, it is not stop there. I also found an interesting Matthijs statement regarding this too:
But don't be panic, this is not a general problem in WordPress. This is a situation which can be avoided by choosing a permalink pattern which allows WordPress to find your posts in an efficient way. WordPress gives site builders a lot of flexibility in how their post URLs are created. There are several attributes can be used, and ordered to your liking. The default "pretty permalink" structure looks like this:
This important note was subsequently added to the Codex page about Using Permalinks:
For performance reason, simply add a numeric field in post permalink to let wordpress works easier and reduce the server performance too. Below are comparison of how should permalink structure built for best option:
Choosing carefully wordpress permalink can help WordPress locate your articles in the most efficient way possible. Oops, if you wonder why the best permalink structure above use .html extenstion. For complete reason why is it so, please see also Using .html Extension in Wordpress Permalink to improve SEO quality for your site.
This would be a problem for any dynamic CMS, not just WordPress. If there isn't some way to narrow down the information in the URL and map it to a specific page or post, the system must perform a lot of database searches to find the correct entry. Unfortunately, it is not stop there. I also found an interesting Matthijs statement regarding this too:
Recently I discovered that the current way wordpress handles permalinks is not scalable. All rewrite_rules are at the moment held in a single database field in the wp_options table. If you have a few dozens pages and posts, you have maybe a few hundred rewrite_rules in it and all is well. But as soon as you start to have a few hundred pages and attachments, the amount of rewrite_rules explodes as well as the field size. This also depends on the permalinks settings. On one of my sites I can't even open the database field to take a look because my browser and text editor crash because of its size.
/%year%/%monthnum%/%postname%/or
http://mywpsite.com/2011/12/my-post/There are several structure tags which can be used to form permalinks: %year%, %monthnum%, %day%, %hour%, %minute%, %second%, %postname%, %post_id%, %category%, %tag%, and %author%. As mentioned earlier, this gives a lot of flexibility in how your URLs can appear.
This important note was subsequently added to the Codex page about Using Permalinks:
For performance reasons, it is not a good idea to start your permalink structure with the category, tag, author, or postname fields. The reason is that these are text fields, and using them at the beginning of your permalink structure it takes more time for WordPress to distinguish your Post URLs from Page URLs (which always use the text "page slug" as the URL), and to compensate, WordPress stores a lot of extra information in its database (so much that sites with lots of Pages have experienced difficulties). So, it is best to start your permalink structure with a numeric field, such as the year or post ID.Conclusion
For performance reason, simply add a numeric field in post permalink to let wordpress works easier and reduce the server performance too. Below are comparison of how should permalink structure built for best option:
Bad:
/%postname%/%post_id%/
/%category%/%postname%/
Better:
/%post_id%/%postname%/
/%year%/%category%/%postname%/
Best:
/%post_id%/%postname%.html
/%year%/%postname%.html
Choosing carefully wordpress permalink can help WordPress locate your articles in the most efficient way possible. Oops, if you wonder why the best permalink structure above use .html extenstion. For complete reason why is it so, please see also Using .html Extension in Wordpress Permalink to improve SEO quality for your site.