What is QP layer?

Question

From blogs.innodb.com: InnoDB Memcached with Binlog Capability

In our earlier Labs release, we presented a MySQL NoSQL solution through InnoDB Memcached Daemon Plugin (see earlier Calvin’s and my posts). That earlier release allows the Memcached Plugin directly interacting with InnoDB, completely bypassing MySQL optimizer and QP layers. It differs with another popular MySQL NoSQL solution, HandlerSocket, by skipping even the Handler API layer and directly access the InnoDB through InnoDB APIs. Thus, in theory, it would be simpler and more efficient.

What is QP Layers?

Searching did not yield me any good results. The closest I came to was Query Path. Is this right?

Answer 1

QP most likely stands for Query Parsing.

MySQL Optimizer needs info from the Query Parser to ascertain table names and column names along with associated data types.

I made an earlier post in the DBA StackExchange about how the HandlerSocket bypasses MVCC and row-level locks. I would be a little leary about bypassing even the HandlerSocket. I say that because HandlerSocket has issues with doing reads while there are write operations interacting with the same data. Please make sure the Memcached Plugin does not have the same deficieny. Please check for any known bugs in this matter.