Today we upgraded the PCRE library bundled with MariaDB-10.0 to PCRE-8.34. This PCRE release includes some improvements, fixes for better stability and performance, and gives more compatibility with the Perl regular expressions. I’d like to give details on the PCRE changes that especially affected MariaDB. PCRE now includes support for [[:<:]] and [[:>:]] as used in the BSD […]READ MORE
There's innodb_large_prefix as a possible workaround, which is default in 10.2 https://t.co/URwAEaZcN7
The reason is because MariaDB imposes a maximum of 767 bytes for indexes, and 767 / 4 = 191 (rounded down).
The danger of no Primary Key when replicating in RBR (partial protection with MariaDB 10.1) https://t.co/M6mABJdkmn by @jfg956