# # Some special cases with empty tables # --disable_warnings drop table if exists t1; --enable_warnings create table t1 (nr int(5) not null auto_increment,b blob,str char(10), primary key (nr)); --disable_ps2_protocol select count(*) from t1; select * from t1; select * from t1 limit 0; --enable_ps2_protocol show status like "Empty_queries"; drop table t1; # # Accessing a non existing table should not increase Empty_queries # --disable_ps2_protocol --error 1146 select * from t2; --enable_ps2_protocol show status like "Empty_queries"; --echo # End of 4.1 tests --echo # --echo # MDEV-30333 Wrong result with not_null_range_scan and LEFT JOIN with empty table --echo # set @save_optimizer_switch=@@optimizer_switch; CREATE TABLE t1 (a INT, b INT) ENGINE=MyISAM; INSERT INTO t1 (b) VALUES (1),(2); CREATE TABLE t2 (c INT) ENGINE=MyISAM; SET optimizer_switch= 'not_null_range_scan=off'; # Default explain extended SELECT b FROM t1 LEFT JOIN t2 ON t2.c = a WHERE a IS NULL ORDER BY b; SELECT b FROM t1 LEFT JOIN t2 ON t2.c = a WHERE a IS NULL ORDER BY b; SET optimizer_switch = 'not_null_range_scan=on'; explain extended SELECT b FROM t1 LEFT JOIN t2 ON t2.c = a WHERE a IS NULL ORDER BY b; SELECT b FROM t1 LEFT JOIN t2 ON t2.c = a WHERE a IS NULL ORDER BY b; flush tables; SELECT b FROM t1 LEFT JOIN t2 ON t2.c = a WHERE a IS NULL ORDER BY b; drop table t1,t2; --echo # Second test in MDEV-30333 CREATE TABLE t1 (a int, b varchar(10)) ENGINE=MyISAM; INSERT INTO t1 VALUES (69,'foo'),(71,'bar'); CREATE TABLE t2 (c int) ENGINE=MyISAM; INSERT INTO t2 VALUES (1),(2); CREATE TABLE t3 (d int, e int, KEY(e)) ENGINE=MyISAM; SELECT * FROM t1 LEFT JOIN t2 LEFT JOIN t3 ON t3.e = t3.d ON 1; SET optimizer_switch = 'not_null_range_scan=on'; SELECT * FROM t1 LEFT JOIN t2 LEFT JOIN t3 ON t3.e = t3.d ON 1; DROP TABLE t1, t2, t3; set @@optimizer_switch=@save_optimizer_switch; --echo End of 10.5 tests