五个简单SQL性能测试题，及格率只有40%
CREATE TABLE t1 ( id INT NOT NULL, dt DATE, PRIMARY KEY (id));CREATE INDEX idx1 ON t1(dt);SELECT * FROM t1 WHERE TO_CHAR(dt, 'YYYY
dbo
CREATE TABLE t1 ( id INT NOT NULL, dt DATE, PRIMARY KEY (id));CREATE INDEX idx1 ON t1(dt);SELECT * FROM t1 WHERE TO_CHAR(dt, 'YYYY