get_nested_categories() and friends use a lot of DB queries

[mdawaffe]

get_nested_categories(), cat_rows(), and wp_dropdown_cats() spend at least one query per category. The attached patch uses the built in caching to eliminate all but one or two queries. I do not know if this proposed method is actually any faster.

Note: these are admin-side only functions, so DB hits aren't as important.

[mdawaffe]

Reduce DB hits by orders of magnitude for admin side category template functions.

[ryan]

Can get_categories() be used in here?

[mdawaffe]

The advantage of get_all_category_ids is that, with the current cache implementation, it does the following query the first time it's run and caches the result in a PHP variable (and on the file system if it can).

SELECT * FROM wp_categories

get_categories(), though much more robust, does no caching. Without adding caching to gote_categories(), even if we're careful within one function, we'll still run a SELECT for each function dealing with the categories table. For example, categories.php run both cat_rows() and wp_dropdown_cats().

[ryan]

Stale patch. Needs update.

[markjaquith]

mdawaffe,

Can you freshen this up for 2.1, or should we push it off to 2.2 (remember, 4 months from 2.1 to 2.2)?

[mdawaffe]

Push it. The category get functions got an overhaul which fixed most of this up.

I can revisit it later, but it's not worth looking at now to save one or two queries in the admin.

[pishmishy]

Bumping milestone for feature freeze. Bordlerline as to whether this is a feature or simply an enhancement that could be included as a fix. Patch is stale though so I'll bump.

[ryan]

wp_category_checklist()

[ryan]

(In [7737]) wp_category_checklist() and wp_link_category_checklist() to replace the nested cats code. see #2621

[ryan]

(In [7739]) Don't query post cats if no post. see #2621

[Denis-de-Bernardy]

fixed?