Following the iMoot, and my presentation on writing MySQL queries in Moodle, I’ve been looking in more detail at the extensive changes in logged within Moodle 2.7. One of the things that will change the way we develop reports in future is that the well known mdl_log table is now a legacy table, and shouldn’t be used, and is replaced by the Standard Moodle Log table.
As you can see from the screenshots, this new table is capturing a lot more data, which will mean that more sophisticated queries can be developed using this table. However, any queries which use the old mdl_log table, from Moodle 2.7 will need re-writing completely. This can be avoided if Moodle on configured to still use the mdl_log table, but this will be slower. And if both are used, it will be significantly slower.
There is no doubt that the new Standard Log Table is the way to go, and Moodle Admins should be planning on using the new system, and disabling the legacy mdl_log table, but will need to think carefully about reports that are currently being used, and put aside some time to develop new versions.