Bind variables in query

Question

Hi,
I have a query that is taking up so much memory of the shared pool that I get this Oracle error message: ORA-04031: unable to allocate 1120 bytes of shared memory ("shared pool","SELECT DECODE(NULL,NULL,'Sta...","sql area","strdef & evalk : evalks")
From reading on asktom, I understand that I need to check for bind variables in my SQL statement, as these are the main cause of poor performance. I'm not sure how to correct my SQL statement. I thought I was already using bind variables. Here's my code:
DECLARE
   q VARCHAR2(32767);
BEGIN
q:='SELECT '||
'DECODE(NULL,NULL,''Station to Station'') as col1, '||
'sum(s_to_s_norm) as col2, '||
'sum(s_to_s_pre) as col3,  '||
'sum(s_to_s_norm)+sum(s_to_s_pre) as col4, '||
'sum(s_to_s_busy) as col5, '||
'sum(s_to_s_LT) as col6, '||
'sum(s_to_s_GT) as col7, '||
'sum(s_to_s_busy)+sum(s_to_s_LT)+sum(s_to_s_GT) as col8, '||
'sum(s_to_s_norm)+sum(s_to_s_pre)+sum(s_to_s_busy)+sum(s_to_s_LT)'||
'+sum(s_to_s_GT) as col9, '||
'DECODE(NULL,NULL,1) as col10 '||
'FROM traffic_sum_view '||
'WHERE TO_DATE('||:SORTFIELD||') '||
'BETWEEN TO_DATE(substr(:STARTDATE,1,19),''dd-MON-YYYY hh24:mi'') '||
'AND TO_DATE(substr(:STOPDATE,1,19),''dd-MON-YYYY hh24:mi'') '||
'AND switch_id = ''' ||:P1_SWITCH_ID|| ''';';
return q;
end;                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   

Answer 1

Hi,
I have a query that is taking up so much memory of
the shared pool that I get this Oracle error message:
ORA-04031: unable to allocate 1120 bytes of shared
memory ("shared pool","SELECT
DECODE(NULL,NULL,'Sta...","sql area","strdef & evalk
: evalks")
From reading on asktom, I understand that I need to
check for bind variables in my SQL statement, as
these are the main cause of poor performance. I'm
not sure how to correct my SQL statement. I thought
I was already using bind variables. Here's my code:
DECLARE
q VARCHAR2(32767);
IN
q:='SELECT '||
'DECODE(NULL,NULL,''Station to Station'') as col1,
'||
'sum(s_to_s_norm) as col2, '||
'sum(s_to_s_pre) as col3,  '||
'sum(s_to_s_norm)+sum(s_to_s_pre) as col4, '||
'sum(s_to_s_busy) as col5, '||
'sum(s_to_s_LT) as col6, '||
'sum(s_to_s_GT) as col7, '||
'sum(s_to_s_busy)+sum(s_to_s_LT)+sum(s_to_s_GT) as
col8, '||
'sum(s_to_s_norm)+sum(s_to_s_pre)+sum(s_to_s_busy)+sum
(s_to_s_LT)'||
'+sum(s_to_s_GT) as col9, '||
'DECODE(NULL,NULL,1) as col10 '||
'FROM traffic_sum_view '||
'WHERE TO_DATE('||:SORTFIELD||') '||
'BETWEEN
TO_DATE(substr(:STARTDATE,1,19),''dd-MON-YYYY
hh24:mi'') '||
'AND TO_DATE(substr(:STOPDATE,1,19),''dd-MON-YYYY
hh24:mi'') '||
'AND switch_id = ''' ||:P1_SWITCH_ID|| ''';';
return q;
end;Bind variables are ENCOURAGED in SQL Selects!! They allow the database to reuse your query as apposed to recompiling the code each time.. Where on AskTom did you see a statement advising against Bind Variables??
Thank you,
Tony Miller
UTMB/EHN