sql oracle was acquired by wealthy use mysql -> MariaDB
NoSQL key-value type redis document type mogodb search engine solr es-column Hbase (adjacent data more easily compressed, reducing io, distributed memory) graphics (social relationships)
mysql strong on the plug-in engine, each table can be set separately engines alone, oracle avoid hard parsing, strong in bind variables, but not the same query on the failure
First of sql hash operational planning and execution if returned to find sql statement, did not find into the oracle optimizer to create a parser to parse, execution plan in the library cache, then that is the actuator
Including shared pool library cache, data dictionary buffer pools
Library Cache: Cache sql and implementation plan
Dictionary data buffer pool: object definition, such as the view table index
mysql
1 query caching bad effect, abandoned 8.0
2 parser: syntax and semantics
Optimizer 3: execution path sql statement determines, according to the whole table or an index such as
4 Actuators before the judge whether the user has permissions to 8.0, if you set the cache, the cache will query results
show profile view on some sql execution time of each part
After the default InnoDB 5.5, support services, and line lock, foreign key constraints etc.
MylSam: Before 5.5, none of the above support, small footprint, fast, separate read and write scenarios
