Indexing performance problem on MySQL 8

[romainruaud]

Since this commit : 8018fce

And the integration of the patch provided by @Wohlie we identified an issue on a client running MySQL 8.

The indexing process became suddenly very slow (from 2h to 20h) after upgrading Elasticsuite.

It seems that the query generated by the patch is problematic on MySQL 8.

Here is the explain on the client server :

For unknown reasons, it seems that it will use the index on "STORE_ID".

Here is the explain on another client server running MariaDB :

Here it uses the index on ATTRIBUTE_ID.