Manual:Comment table

Edits, blocks, and other actions typically have a textual comment describing the action. They are stored in a separate table to reduce the size of the main tables, and to allow for de-duplication.

De-duplication is currently best-effort to avoid locking on inserts that would be required for strict de-duplication. There may be multiple rows with the same and.

This table was introduced in.

comment_id
Unique ID to identify each comment.

comment_hash
Hash of and, for de-duplication.

comment_text
Text comment summarizing the change, e.g. an editor's edit summary. This text is shown in the history and contributions. It is also used for recent changes, related changes, watchlists, and, in the case of page creation, for the list of new pages. It is rendered in a sanitized subset of wiki markup by. Size limits are enforced at the application level, and should take care to crop UTF-8 strings appropriately.

comment_data
JSON data, intended for localizing auto-generated comments. This holds structured data that is intended to be used to provide localized versions of automatically-generated comments. When not empty, should be the generated comment localized using the wiki's content language.