MySQL Architecture and Concepts

MySQL Architecture and Concepts:-

MySQL Architecture

Connection Manager :
The Connection Manager listens for incoming connection from clients and dispatches the requests to the Thread Manager

Connection Thread :
The Connection Thread is the heart of the client processing which establishes connection.

Thread Manager :
The Thread Manager is responsible for keeping track of threads and for making sure a thread is allocated to handle the connection from a client.

User Authentication Module :
The user Authentication module authenticates the connection user and initializes the structures and variables containing the information on his level of privileges.

Command Dispatcher :
The Command Dispatcher is the responsible for directing requests to the lower-level modules that will know how to reslove them.

Parser :
The Parser is responsible for parsing queries and generating a parse tree.

Query Cache Module :
The Query Cache Module caches query results and tries to short-circuit the execution of queries by delivering the cached result whenever possible.

Optimizer :
The Optimizer is responsible for creating the best strategy to answer the query and executing it to deliver the result to the client.

Table Modification Modules :
This collection of modules is responsible for operations such as creating ,deleting ,renaming,dropping,updating or inserting into a table.

Table Maintenance Module :
the Table Maintenance Module is responsible for table maintenance operations such as check,repair,back up,restore,optimize and analyze. This module comes into picture when a table is corrupted.

Status Reporting Module :
The Status Reporting module is responsible for answering queries about server configuration settings,performance tracking varibales,table structure information,replication progress,condition of the tables cache and other things.

Replication Master Module :
The Replication Master Module is responsible for the replication functionality on the master. then most common operation for this module is to deliver continuous feed of the replication log events to the slave upon request.

Replication Slave Module:
The Replication Slave Module is responsible for the replication functionality of the slave. the role of the slave is to retrieve updates from the master and apply them on the slave.

Table Manager :
The Table Manager is responsible for creating ,reading and modifying the table definition files(.frm extension),maintaining a cache of the table descriptor called table cache and managing table-level locks.