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| SELECT COUNT(*) FROM salaries;
SELECT * FROM salaries ORDER BY emp_no DESC LIMIT 10; SELECT * FROM salaries ORDER BY emp_no LIMIT 0,10;
SELECT * FROM salaries ORDER BY salary DESC LIMIT 10; SELECT * FROM salaries ORDER BY salary DESC LIMIT 10,100;
ALTER TABLE salaries ADD INDEX index_sa(salary);
CREATE INDEX index_sa ON salaries(salary);
ALTER TABLE salaries DROP INDEX index_sa;
DROP INDEX index_sa ON salaries;
EXPLAIN SELECT * FROM salaries ORDER BY emp_no DESC LIMIT 10;
EXPLAIN SELECT * FROM salaries ORDER BY salary DESC LIMIT 10; \G
SHOW CREATE TABLE salries;
CREATE TABLE index1 ( id INT, NAME VARCHAR(20), sex BOOLEAN, INDEX(id) ); SHOW CREATE TABLE index1;
CREATE TABLE index1_( id INT PRIMARY KEY, NAME VARCHAR(20), sex BOOLEAN ); SHOW CREATE TABLE index1_;
DROP TABLE index2; CREATE TABLE index2( id INT, NAME VARCHAR(20), sex BOOLEAN, UNIQUE INDEX index2_id(id ASC) ); SHOW CREATE TABLE index2;
CREATE TABLE index2_( id INT UNIQUE, NAME VARCHAR(20), sex BOOLEAN ); SHOW CREATE TABLE index2_;
CREATE TABLE index3( id INT, info VARCHAR(20), FULLTEXT INDEX index3_info(info) ) ENGINE = MYISAM;
CREATE TABLE index4( id INT, fullname VARCHAR(30), INDEX index4_fn(fullname(10)) ); SHOW CREATE TABLE index4;
CREATE TABLE index5( id INT, fullname VARCHAR(30), sex CHAR(4), INDEX index5_fs(fullname,sex) ); SHOW CREATE TABLE index5;
CREATE TABLE index6( id INT, SPACE GEOMETRY NOT NULL, SPATIAL INDEX index6_sp(SPACE) ) ENGINE = MYISAM; SHOW CREATE TABLE index6;
SELECT * FROM employees WHERE first_name = 'Georgi';
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