DB schema clean-ups

[Denis-de-Bernardy]

While looking into #9422, it occurred to me that some DB fields weren't necessarily used today. Namely:

links.link_category int(20) seems to be overridden by the terms schema.

The same goes for posts.post_category int(4).

It might be that they've been left around for obsolete plugins, though. In case this isn't the case, the attached patch, for 2.8 trunk, will remove them.

[Denis-de-Bernardy]

Marking as needs-testing, in case their absence has any impact I've missed by scanning the source code.

[Denis-de-Bernardy]

use int(11) rather than bigint(20) unsigned, for smaller indexes (and thus faster queries)

[Denis-de-Bernardy]

more relevant text fields: text is 65kb, mediumtext is 16MB, longtext is 4GB - an rss field stored in wp_options is only rarely larger than 65kb, and no post would ever be larger than 16MB

[Denis-de-Bernardy]

the same patch, keeping comment_author and post_title as text fields in case this was needed for any reason

[Denis-de-Bernardy]

smaller int fields. surely no post will have over 65k comments?

[Denis-de-Bernardy]

drop user_status field -- see ​http://comox.textdrive.com/pipermail/wp-hackers/2009-January/023550.html

[ryan]

(In [10895]) Drop post_category and link_category from the schema. Props Denis-de-Bernardy. see #9435

[MichaelH]

Is this correct?

By dropping post_category and link_category, new installs will not see those columns, but upgraded databases will still have the two columns.

[ryan]

Correct. dbDelta() doesn't handle deleting old columns.

[ryan]

user_status, BTW, is needed by bbPress.

[Denis-de-Bernardy]

I take it the other ones are not to be used? close as fixed, or move to 2.9 for the text/varchar/int cleanups?

[ryan]

2.9 sounds good for the type cleanups.

[SergeyBiryukov]

Follow-up: #51288