Which version of MariaDB and php is faster for WordPress?

hello
as I want to run a heavy website with WordPress and woocommerce
1) I want to know which one has the best performance for WordPress:
MaraDB 10.0 , MariaDB 10.1 , MariaDB 10.2 or MariaDB 10.3?
2) and between php versions: php7 , 7.1, 7.2 or 7.3 (I guess 7.3 is not a good idea)
and also I found in the folder and file wp-includes/default-constants.php
I have seen that the memory is limited to 40M while the default memory_limit in php.ini is 2GB (I have a dedicated server)
3) may 40M limit the memory for the website?

• This topic was modified 5 years, 11 months ago by Steven Stern (sterndata).