set echo on;
recreate table t_main(id int primary key);
commit;
recreate table t_selected(id int primary key);
commit;
-------------------------------
insert into t_main(id)
with recursive
r as(select 0 i from rdb$database union all select i+1 from r where r.i<999)
select n1.i*1000+n0.i
from r n1,r n0
order by rand();
commit;
insert into t_selected(id)
with recursive
r as(select 0 i from rdb$database union all select i+1 from r where r.i<9)
select n1.i*10+n0.i
from r n1,r n0;
commit;
set stat on;
select count(*)
from t_main
where id in (
1, 11, 21, 31, 41, 51, 61, 71, 81, 91,
2, 12, 22, 32, 42, 52, 62, 72, 82, 92,
3, 13, 23, 33, 43, 53, 63, 73, 83, 93,
4, 14, 24, 34, 44, 54, 64, 74, 84, 94,
5, 15, 25, 35, 45, 55, 65, 75, 85, 95,
6, 16, 26, 36, 46, 56, 66, 76, 86, 96,
7, 17, 27, 37, 47, 57, 67, 77, 87, 97,
8, 18, 28, 38, 48, 58, 68, 78, 88, 98,
9, 19, 29, 39, 49, 59, 69, 79, 89, 99,
10, 20, 30, 40, 50, 60, 70, 80, 90, 100
);
select count(*)
from t_main m
join t_selected s on m.id=s.id;
set stat off;
commit;
/* результат на обычной рабочей станции:
COUNT
============
100
Current memory = 71909016
Delta memory = 187704
Max memory = 81663420
Elapsed time= 0.00 sec
Buffers = 16384
Reads = 0
Writes 0
Fetches = 616
select count(*)
from t_main m
join t_selected s on m.id=s.id;
COUNT
============
100
Current memory = 71731064
Delta memory = -177952
Max memory = 81663420
Elapsed time= 0.02 sec
Buffers = 16384
Reads = 0
Writes 0
Fetches = 825
set stat off;
commit;
*/ |