Function Issues - Query

Question

Hi Guys,
The below is just a query. Given are two codes for a function, when I executed the first it was giving erronous result and was taking about 2 minutes to give out that error but when I made the changes in second and executed it worked perfectly fine and that too withing 2 secs.
Code 1:
CREATE OR REPLACE FUNCTION BUSOBJ.pos_countrycode_lookup (
   record_locator      VARCHAR2,
   pnr_creation_date   VARCHAR2
   RETURN VARCHAR2
IS
   pnr_id                  NUMBER;
   city_code               VARCHAR2 (10 BYTE);
   country_code            VARCHAR2 (10 BYTE);
   record_loc              VARCHAR2 (10 BYTE);
   pnr_create_dt           DATE;
   org_booking_city        VARCHAR2 (10 BYTE);
   org_booking_agent       VARCHAR2 (10 BYTE);
   org_booking_city_code   VARCHAR2 (10 BYTE);
   rec_iso_country_code    VARCHAR2 (10 BYTE);
   gds_country_code        VARCHAR2 (10 BYTE);
   is_country_code         VARCHAR2 (10 BYTE);
BEGIN
   BEGIN
      SELECT   ph.pnr_id_pk, ph.record_locator, ph.pnr_creation_date_time,
               ph.original_booking_city, ph.original_booking_agent,
               ph.original_booking_city_code, pd.rec_loc_iso_country_code,
               pd.gds_location_country_iso, ph.iso_country_code
          INTO pnr_id, record_loc, pnr_create_dt,
               org_booking_city, org_booking_agent,
               org_booking_city_code, rec_iso_country_code,
               gds_country_code, is_country_code
          FROM pnr_hdr ph, pos_details pd
         WHERE ph.record_locator = record_locator
           AND TRUNC (ph.pnr_creation_date_time) = pnr_creation_date
           AND ph.pnr_id_pk = pd.pnr_id_fk
           AND ph.delete_flag IS NULL
           AND ROWNUM = 1
      GROUP BY ph.pnr_id_pk,
               ph.record_locator,
               ph.pnr_creation_date_time,
               ph.original_booking_city,
               ph.original_booking_agent,
               ph.original_booking_city_code,
               pd.rec_loc_iso_country_code,
               pd.gds_location_country_iso,
               ph.iso_country_code;
   END;Code 2:
CREATE OR REPLACE FUNCTION BUSOBJ.pos_countrycode_lookup (
   record_locator      VARCHAR2,
   pnr_creation_date   VARCHAR2
   RETURN VARCHAR2
IS
   pnr_id                  NUMBER;
   city_code               VARCHAR2 (10 BYTE);
   country_code            VARCHAR2 (10 BYTE);
   record_loc              VARCHAR2 (10 BYTE);
   pnr_create_dt           DATE;
   org_booking_city        VARCHAR2 (10 BYTE);
   org_booking_agent       VARCHAR2 (10 BYTE);
   org_booking_city_code   VARCHAR2 (10 BYTE);
   rec_iso_country_code    VARCHAR2 (10 BYTE);
   gds_country_code        VARCHAR2 (10 BYTE);
   is_country_code         VARCHAR2 (10 BYTE);
   pnr_locator             VARCHAR2 (10 BYTE);
   pnr_date                VARCHAR2 (20 BYTE);
BEGIN
   pnr_locator := record_locator;
   pnr_date := pnr_creation_date;
   BEGIN
      SELECT   ph.pnr_id_pk, ph.record_locator, ph.pnr_creation_date_time,
               ph.original_booking_city, ph.original_booking_agent,
               ph.original_booking_city_code, pd.rec_loc_iso_country_code,
               pd.gds_location_country_iso, ph.iso_country_code
          INTO pnr_id, record_loc, pnr_create_dt,
               org_booking_city, org_booking_agent,
               org_booking_city_code, rec_iso_country_code,
               gds_country_code, is_country_code
          FROM pnr_hdr ph, pos_details pd
         WHERE ph.record_locator = pnr_locator
           AND TRUNC (ph.pnr_creation_date_time) = pnr_date
           AND ph.pnr_id_pk = pd.pnr_id_fk
           AND ph.delete_flag IS NULL
           AND ROWNUM = 1
      GROUP BY ph.pnr_id_pk,
               ph.record_locator,
               ph.pnr_creation_date_time,
               ph.original_booking_city,
               ph.original_booking_agent,
               ph.original_booking_city_code,
               pd.rec_loc_iso_country_code,
               pd.gds_location_country_iso,
               ph.iso_country_code;
   END;Please can you gurus suggest what mistake I was making in the first piece of code.
Cheers,
Shaz
Edited by: BluShadow on 20-Feb-2012 16:07
Added {noformat}{noformat} tags for readability.  Please read {message:id=9360002} and learn to do this yourself.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               

Answer 1

First statement
WHERE ph.record_locator                      = record_locator
AND TRUNC (ph.pnr_creation_date_time) = pnr_creation_datedifferent from second statement
WHERE ph.record_locator                     = pnr_locator
AND TRUNC (ph.pnr_creation_date_time) = pnr_dateAlso , you have other issues where you are potentially disabling an index by
using
TRUNC (ph.pnr_creation_date_time)  and the fact that you have and ROWNUM=1 in your statements is a possible cause for concern. in 99% of cases this means your query is not restrictive enough.
It needs investigation.
Also , its possible that your second ran query ran quickly because your first query had already retrieved a lot of the data into the required blocks, thus only requiring a logical read where the first query would have required physical reads.
You would need to do an explain plan on the queries to see if this is the case