Changes between ICE 3.5.2 and 4.0.3

It has been a while since my last comparison, but now it's time again. This time a comparison between 3.5.2 and 4.0.3, and indeed a lot of changes has been made. As always also take a look at the release notes.
As described in the release notes, the biggeste changes includes Domain Expert and Rough Queries. There is a lot of information about these on the web, and will not be explained here.
Some of the minor changes includes:

• LOCK TABLE returns wrong command, as ICE doesn't support it.
• Aggregations now supports out of range values, instead of setting default 0.0.
• Better handling of dates during aggregation.
• Better query debug log information, especially for joins.
• Better error handling.
• Exporter acknowledges escape character.

Also changes to the configuration possibilities have been made.

• sync_buffers (flushes table buffers).
• Many configuration options can now be shown using SHOW VARIABLES. All the variables starts with brighthouse_ini.