increase session_cached_cursors

Hello all,

We have performance problem on prod DB, and Oracle ADDM advice us increase size of session_cached_cursors parameter.

We decide find reason of problem.

Here you can find statement which you should run where problem appear.

create table t1 as select sql_text from v$sqlarea;

alter table t1 add sql_text_wo_constants varchar2(3000);

create or replace function
remove_constants( p_query in varchar2 ) return varchar2
as
l_query long;
l_char varchar2(1);
l_in_quotes boolean default FALSE;
begin
for i in 1 .. length( p_query )
loop
l_char := substr(p_query,i,1);
if ( l_char = '''' and l_in_quotes )
then
l_in_quotes := FALSE;
elsif ( l_char = '''' and NOT l_in_quotes )
then
l_in_quotes := TRUE;
l_query := l_query || '''#';
end if;
if ( NOT l_in_quotes ) then
l_query := l_query || l_char;
end if;
end loop;
l_query := translate( l_query, '0123456789', '@@@@@@@@@@' );
for i in 0 .. 8 loop
l_query := replace( l_query, lpad('@',10-i,'@'), '@' );
l_query := replace( l_query, lpad(' ',10-i,' '), ' ' );
end loop;
return upper(l_query);
end;
/
update t1 set sql_text_wo_constants = remove_constants(sql_text);



now we can see result on statement



select sql_text_wo_constants, count(*)
from t1
group by sql_text_wo_constants
having count(*) > 100
order by 2 desc
/

we can see selects which is reason of performance problem.

In these select please use bind variables.