The InnoDB crash recovery performance can be improved a little while not changing the file format.
MDEV-12699 removed unnecessary reads of pages that can be initialized via the redo log. MDEV-19586 will make recovery read the pages in more sequential order.
We should fix some fundamental issues that exist with the current InnoDB redo log record format:
- Records do not contain their length. When buffering records, we must painstakingly parse entire records in order to determine the length. This idea was mentioned in MySQL Bug#82937.
- For B-tree operations, we are writing a lot of redundant data for mlog_parse_index(). We should use a lower-level format and lower-level apply functions. MySQL Bug#82176 merely speeds up the code around mlog_parse_index().
- If a mini-transaction is writing multiple records to a page, the page identifier is being repeated for every record. We should omit the page identifier if multiple consecutive records are modifying the same page.
In this task, we will only improve the redo log record format. Format changes to the redo log blocks and files will be covered by MDEV-14425.