CREATE TABLE t1 (i INT) ENGINE = INNODB;
​
InnoDB: default in MySQL 5.7. 
    transaction-safe (ACID compliant)：commit, rollback, and crash-recovery
    row-level locking (without escalation to coarser granularity locks) 
    Oracle-style consistent nonlocking reads
    clustered indexes to reduce I/O for common queries based on primary keys
    FOREIGN KEY referential-integrity constraints
MyISAM: 
    Table-level locking. 
    often used in read-only or read-mostly workloads.
Merge: 
    logically group a series of identical MyISAM tables and reference them as one object.     
Memory or HEAP:
    Its use cases are decreasing:
        InnoDB with its buffer pool memory area
        NDBCLUSTER provides fast key-value lookups for huge distributed data sets
NDB or NDBCLUSTER: highest possible degree of uptime and availability.
Federated: link separate MySQL servers to create one logical database
CSV: Its tables are really text files with comma-separated values.
Archive: compact, unindexed tables
Blackhole: 
    not store data, Queries always return an empty set. 
    can be used in replication configurations
Example: illustrates how to begin writing new storage engines.

CREATE TABLE t1 (jdoc JSON);
INSERT INTO t1 VALUES('{"key1": "value1", "key2": "value2"}');
​
SELECT JSON_ARRAY('a', 1, NOW());
SELECT JSON_OBJECT('key1', 1, 'key2', 'abc');
SELECT JSON_MERGE('["a", 1]', '{"key": "value"}');
​
SET @j = JSON_OBJECT('key', 'value');
SELECT @j;
​
# escape quote character
'{"mascot": "... \\"Sakila\\"."}'
JSON_OBJECT("mascot", "... \"Sakila\".")
JSON_OBJECT('mascot', '... "Sakila".')    # NO_BACKSLASH_ESCAPES
​
# JSON values is case sensitive
SELECT CAST('null' AS JSON); # `null`, `true`, and `false` always lowercase
​
SELECT col->"$.mascot" FROM qtest;          # "... \"Sakila\"."
SELECT sentence->>"$.mascot" FROM facts;    # ... "Sakila".
​
ORDER BY CAST(JSON_EXTRACT(jdoc, '$.id') AS UNSIGNED)

CREATE TABLE products(id INTEGER NOT NULL PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(255) NOT NULL,
price DECIMAL(9,2) NOT NULL,
stock INTEGER NOT NULL,
attr VARCHAR(1024),
CHECK (attr IS NULL OR JSON_VALID(attr)));
​
INSERT INTO products VALUES(NULL, 'Blouse', 17, 15, '{"colour": "white"}');
UPDATE products SET attr = JSON_REPLACE(attr, '$.colour', 'red') WHERE name = 'Blouse';
​
ALTER TABLE products ADD attr_colour VARCHAR(32) AS (JSON_VALUE(attr, '$.colour'));
​
CREATE INDEX products_attr_colour_ix ON products(attr_colour);
EXPLAIN SELECT * FROM products WHERE attr_colour = 'white';     # verify index