usually generated SQL query can use a better index this way

We were not able to export and import back roles of a document when more than
one local role group id was used.

It can only work with default id generator and anyway catalog does not
understand this syntax, so this has no effect

you can apply this change on the existing table by the following query :

ALTER TABLE stock DROP INDEX `section_uid_portal_type`, ADD INDEX `section_uid_portal_type_mirror_section_uid` (`section_uid`,`portal_type`, `mirror_section_uid`);

Do not try to translate user input by using Localizier as it will fill up its internal structure (very inefficient) and lead to increase of ZODB (every modification is a new Localizer object holding all entries).

otherwise the result for 2-bit input is unreadable 2-bit with current imagemagick.

Otherwise a TypeError exception is raised when calling Connection().columns().

Inventory movements are not indexed into stock table every time, and
inventory_stock table no longer exists. Thus we use movement table instead.

that raises an Exception for PDF documents without any metadata.

With due warnings.

try..except is significantly slower than getattr with default value when
an exception is raised.
defaultdict is faster than calling setdefault.
The two other try..except blocks need more careful analysis of typical
hit-rates to tell if they are optimal.

override _edit() to migrate existing documents if hook is not yet registered.

otherwise the result is unpredictable.

Remove Japanese accounting bt5s as there is no standard like in France, thus making these bt5s useless.

so that we can change the skin selection in each Web Section.

Refactor code and use proper default page templates names so no need to rename manually to enable this bt5.