SQL> set stat on;
SQL> select count(s) from td where s like '%qwertyuiop%';

                COUNT
=====================
              1000000

Current memory = 2763107488
Delta memory = 167184
Max memory = 2766156256
Elapsed time= 8.84 sec
Cpu = 0.00 sec
Buffers = 524288
Reads = 54
Writes = 4558
Fetches = 20762024
SQL>
SQL> select count(s) from td where s NOT like '%qwertyuiop%';

                COUNT
=====================
              9000000

Current memory = 2763428488
Delta memory = -309744
Max memory = 2766156256
Elapsed time= 9.84 sec
Cpu = 0.00 sec
Buffers = 524288
Reads = 72
Writes = 4304
Fetches = 20672085
SQL>
SQL> select count(s) from td where s like '%q%';

                COUNT
=====================
             10000000

Current memory = 2763755936
Delta memory = -1313368
Max memory = 2775462040
Elapsed time= 9.30 sec
Cpu = 0.00 sec
Buffers = 524288
Reads = 83
Writes = 6600
Fetches = 21011277
SQL>
SQL> select count(s) from td where s NOT like '%q%';

                COUNT
=====================
                    0

Current memory = 2764691240
Delta memory = 751192
Max memory = 2775462040
Elapsed time= 9.35 sec
Cpu = 0.00 sec
Buffers = 524288
Reads = 103
Writes = 6634
Fetches = 21005441
SQL>

commit;
recreate table td(id int, s varchar(32760)); commit;
set term ^;
execute block as
begin
  begin
    execute statement 'create sequence g';
    when any do begin end
  end
end^
set term ;^
commit;
alter sequence g restart with 0;
commit;

set term ^;
execute block as
declare n int = 1000000;
declare m int;
begin
m=n; while(m>0) do insert into td(id, s) values( gen_id(g,1), 'q' ) returning :m-1 into m;
m=n; while(m>0) do insert into td(id, s) values( gen_id(g,1), 'qw' ) returning :m-1 into m;
m=n; while(m>0) do insert into td(id, s) values( gen_id(g,1), 'qwe' ) returning :m-1 into m;
m=n; while(m>0) do insert into td(id, s) values( gen_id(g,1), 'qwer' ) returning :m-1 into m;
m=n; while(m>0) do insert into td(id, s) values( gen_id(g,1), 'qwert' ) returning :m-1 into m;
m=n; while(m>0) do insert into td(id, s) values( gen_id(g,1), 'qwerty' ) returning :m-1 into m;
m=n; while(m>0) do insert into td(id, s) values( gen_id(g,1), 'qwertyu' ) returning :m-1 into m;
m=n; while(m>0) do insert into td(id, s) values( gen_id(g,1), 'qwertyui' ) returning :m-1 into m;
m=n; while(m>0) do insert into td(id, s) values( gen_id(g,1), 'qwertyuio' ) returning :m-1 into m;
m=n; while(m>0) do insert into td(id, s) values( gen_id(g,1), 'qwertyuiop' ) returning :m-1 into m;
end^ set term ;^ commit;

SQL> out nul; select count(s) from td; out;
Current memory = 2498097104
Delta memory = -6168
Max memory = 2527625632
Elapsed time= 45.99 sec
Cpu = 0.00 sec
Buffers = 524288
Reads = 1430580
Writes = 0
Fetches = 22860311

SQL> set stat on;
SQL> set term ^;
SQL> execute block returns(cnt int) as
CON> declare n int = 10000000;
CON> declare s varchar(1);
CON> begin
CON>   cnt=0;
CON>   s='q'; --rpad('q',1,' ');
CON>   while (n>0) do begin
CON>     cnt = cnt + iif( s like '%q%', 1, 0);
CON>     n=n-1;
CON>   end
CON>   suspend;
CON> end^
set term ;^
set stat off;

         CNT
============
    10000000

Current memory = 2450526032
Delta memory = -4392
Max memory = 2450628912
Elapsed time= 6.61 sec
Cpu = 0.00 sec
Buffers = 524288
Reads = 0
Writes = 0
Fetches = 0
SQL> set term ;^
SQL> set stat off;