Understanding mysql -- (mysql Learning 1)

Understanding mysql -- (mysql Learning 1) mysql product: cpl protocol and commercial version cpl Protocol: Single-host, cluster version commercial: Classic, standard, enterprise, cluster 2, storage engine: 1. mysql server: mysqld program. (similar to oracle instance) storage engine: Table creation is to select a storage engine. If not selected, myIsam engine is used by default. 2. servers and hosts: client and server parse --> optimize --> execute [mysql database management level | (mysqld)] myIsam/innodb/mysql cluster/falcon/other... [storage engine implementation] file system hardware three types of programs: server programs, client programs, non-client program client programs are accessed through the server (mysqld), and mysqld accesses data through the storage engine. Non-client programs can directly access the storage engine without using mysqld. Start the server: mysqld -- console close the server: mysqladmin-uroot-poracle shutdown; 3. The database is a set of tables logically and physically a collection of files. A folder is created to create a database. the opt File Stores database attributes such as character set and verification. When creating a table, different files are generated based on different storage engines: select @ datadir; configure the database data storage directory select @ basedir; the root directory of the configuration database will be created. frm file, which stores the table structure. myIsam engine: will generate. myd (data file ),. myi (index file) innodb Engine: will generate. idb or. ibdata file. Check whether the configuration is to use a shared tablespace to store data and indexes or an exclusive tablespace to store data and indexes. If the exclusive tablespace is stored, each table will generate one. ibd file. Select @ innodb_data_file_path; configure the name of each file. You can also configure this parameter without configuring... _ home_dir. select @ innodb_data_home_dir; configure the ibdataba data storage directory 4. mysql is a single-process multi-thread 5. You can set show engines for the storage engine on the server and table level; -- check what storage engine your mysql currently provides: show variables like '% storage_engine %'; -- check the default storage engine of your mysql: show create table name; -- It depends on the engine used by a table (the storage engine used for the table is displayed after the parameter engine in the display result ):