sql - left join done after 13 second on 7000 records - mysql -


i have table this:

create table `gps` (   `id` int(11) not null,   `driver_id` int(11) not null,   `trucks_drivers_id` int(11) not null,   `x` varchar(100) collate utf8_persian_ci not null,   `y` varchar(100) collate utf8_persian_ci not null,   `speed` varchar(100) collate utf8_persian_ci not null,   `time_stamp` timestamp not null default current_timestamp ) engine=myisam default charset=utf8 collate=utf8_persian_ci;

number of records 7000.

my query :

select m1.*             gps m1 left join gps m2              on (m1.driver_id = m2.driver_id , m1.id < m2.id)             m2.id null

but result take long time:

showing rows 0 - 4 (5 total, query took 13.1221 seconds.)

why?!

someone tell me use index speed query. got syntax error:

select m1.* gps m1 left join gps m2 force index(m1.*) on (m1.driver_id = m2.driver_id , m1.id < m2.id) m2.id null

for query:

select m1.* gps m1 left join      gps m2      on m1.driver_id = m2.driver_id , m1.id < m2.id m2.id null;

you want index on gps(driver_id, id). need create index before can use it:

create index idx_gps_driverid_id on gps(driver_id, id);

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