The problem is that the "=" in MySQL and MSSQL is using collation rules, in PostgreSQL and Oracle it is using binary string comparison. This is surprising for many developers, it creates major problems in glossary, tags, course shortnames, user names, etc. for non-english languages because different accent difference sometimes makes a work meaning different.

After the like fixes in MDL-23888 it makes sense to fix get_records() and friends to make them use binary comparisons consistently via new $DB->sql_binary_comparison().

I have discussed this with Eloy today, he seemed to be surprised too and gave +2 for commit...