In terms of start up time, I can confirm that by having 150000 tables and having these settings on PS 5.6.24:
a) Start up time is around 60 seconds
[mysqld]
table_definition_cache = 10000
performance_schema = on
b) Start up time is around 3 seconds
[mysqld]
table_definition_cache = 10000
performance_schema = 0
In terms of start up time, I can confirm that by having 150000 tables and having these settings on PS 5.6.24: n_cache = 10000
a) Start up time is around 60 seconds
[mysqld]
table_definitio
performance_schema = on
b) Start up time is around 3 seconds n_cache = 10000
[mysqld]
table_definitio
performance_schema = 0