Sessions on memcached, redis or sql?

Question

PHP

There was a need to rewrite the session mechanism (for complete control over them - deletion, etc.)
But here's the thing, I have not worked with Redis and memcached before, I heard and read about memcached, but still there are ambiguities ..
What is best rewrite and why? I would like to hear your opinion ..
as far as I understand, scoring 300MB of memcache, I take away 300MB of RAM, is this reasonable?
but again, if you do it in sql, each time you access the database, etc. ...
What do you say?

Answer 1

You provide a strange choice :) Memcached is volatile, in general RAM-dependent things are usually used as "quick access to resources from SQL", the cache is shorter.
Personally, I store in sql, but the trend is better in noSQL (which one is not important, choose what is best for you in mastering), a response of 4ms or 5ms (exaggerated) will not play a special role.
Plus that you have "partial" control - maybe there is "full" there (on github, for example)

Answer 2

Are you aware that sessions can be deleted? And it seems to me that you do not know this.
About Redis / Memcached - eax.me/redis