Trap update error for insert!

Question

Hi, I have a table approx 2 million records which is updated daily from a staging table that is loaded from file. It's taking approx 7 hours as it searches for a record and if it exists, otherwise it inserts.
I was thinking that a faster method would be to bulk collect and update, then trap the error if the record to be updated doesn't exist, and insert the record.
I'm on Oracle 8i.
Question: Would this be the most efficient way to perform the task?
If so would anyone out there have some sample code to do it?
Your help would be very much appreciated.

Answer 1

Hi,
There's only one constraint on the target:
CREATE UNIQUE INDEX XPKGMENT_V ON GMENT_V
(DATE_START, DATE_END, ORI, FNUMBER,
CLASS_CD, DOW)
CURSOR cur IS
SELECT BEG_DATE,
     END_DATE,
FNUMBER,
ORIG,
CLASS_CD,
DATA_TYPE_CD,
DOW,
TTC,
PSEUDO,
PRORATE
FROM stage_gment_v;
rec cur%rowtype;
rowcount      number(7);
row_exists      number(1);
BEGIN
OPEN cur;
rowcount := 0;
row_exists := 0;
LOOP
FETCH cur INTO rec;
EXIT WHEN cur%NOTFOUND;
rowcount := rowcount + 1;
row_exists := 0;
BEGIN
SELECT 1 INTO row_exists          
FROM gment_v r
WHERE r.date_start = rec.beg_date
AND r.orig = rec.orig
AND r.class_cd = rec.class_cd
AND ( r.dow = rec.dow
OR ( rec.dow IS NULL AND r.dow IS NULL) )
AND ( r.fnumber = rec.fnumber
OR ( rec.fnumber IS NULL AND r.fnumber IS NULL));
EXCEPTION
WHEN NO_DATA_FOUND THEN
row_exists := 0;
END;
-- update if a row already exists
IF ( row_exists = 1 ) THEN
UPDATE gment_v r
SET TTC = rec.ttc,
PSEUDO = rec.pseudo,
PRORATE = rec.prorate
WHERE r.date_start = rec.beg_date
AND r.orig = rec.orig
AND r.class_cd = rec.class_cd
AND ( r.dow = rec.dow
OR ( rec.dow IS NULL AND r.dow IS NULL) )
AND ( r.fnumber = rec.fnumber
OR ( rec.fnumber IS NULL AND r.fnumber IS NULL));
updates := updates +1;
ELSE
-- create if does not exist already
INSERT INTO gment_v(
DATE_START,
DATE_END,
          FNUMBER,
          ORIG,
          CLASS_CD,
          DATA_TYPE_CD,
          DOW,
          TTC,
          PSEUDO,
          PRORATE)
VALUES ( rec.beg_date,
rec.end_date,
          rec.fnumber,
          rec.orig,
          rec.class_cd,
          rec.data_type_cd,
          rec.dow,
          rec.ttc,
          rec.pseudo,
          rec.prorate) ;
END IF;
END LOOP;