Request some help, over procedure's performance uses regular expressions for its functinality

Question

Hi All,
        Below is the procedure, having functionalities of populating two tables. For first table, its a simple insertion process but for second table, we need to break the soruce record as per business requirement and then insert into the table. [Have used regular expressions for that]
        Procedure works fine but it takes around 23 mins for processing 1mm of rows.
        Since this procedure would be used, parallely by different ETL processes, so append hint is not recommended.
        Is there any ways to improve its performance, or any suggestion if my approach is not optimized?  Thanks for all help in advance.
CREATE OR REPLACE PROCEDURE SONARDBO.PRC_PROCESS_EXCEPTIONS_LOGS_TT
     P_PROCESS_ID       IN        NUMBER, 
     P_FEED_ID          IN        NUMBER,
     P_TABLE_NAME       IN        VARCHAR2,
     P_FEED_RECORD      IN        VARCHAR2,
     P_EXCEPTION_RECORD IN        VARCHAR2
    IS
    PRAGMA AUTONOMOUS_TRANSACTION;
    V_EXCEPTION_LOG_ID     EXCEPTION_LOG.EXCEPTION_LOG_ID%TYPE;
    BEGIN
    V_EXCEPTION_LOG_ID :=EXCEPTION_LOG_SEQ.NEXTVAL;
         INSERT INTO SONARDBO.EXCEPTION_LOG
             EXCEPTION_LOG_ID, PROCESS_DATE, PROCESS_ID,EXCEPTION_CODE,FEED_ID,SP_NAME
            ,ATTRIBUTE_NAME,TABLE_NAME,EXCEPTION_RECORD
            ,DATA_STRUCTURE
            ,CREATED_BY,CREATED_TS
         VALUES           
         (   V_EXCEPTION_LOG_ID
            ,TRUNC(SYSDATE)
            ,P_PROCESS_ID
            ,'N/A'
            ,P_FEED_ID
            ,NULL 
            ,NULL
            ,P_TABLE_NAME
            ,P_FEED_RECORD
            ,NULL
            ,USER
            ,SYSDATE  
        INSERT INTO EXCEPTION_ATTR_LOG
            EXCEPTION_ATTR_ID,EXCEPTION_LOG_ID,EXCEPTION_CODE,ATTRIBUTE_NAME,SP_NAME,TABLE_NAME,CREATED_BY,CREATED_TS,ATTRIBUTE_VALUE
        SELECT
            EXCEPTION_ATTR_LOG_SEQ.NEXTVAL          EXCEPTION_ATTR_ID
            ,V_EXCEPTION_LOG_ID                     EXCEPTION_LOG_ID
            ,REGEXP_SUBSTR(str,'[^|]*',1,1)         EXCEPTION_CODE
            ,REGEXP_SUBSTR(str,'[^|]+',1,2)         ATTRIBUTE_NAME
            ,'N/A'                                  SP_NAME    
            ,p_table_name
            ,USER
            ,SYSDATE
            ,REGEXP_SUBSTR(str,'[^|]+',1,3)         ATTRIBUTE_VALUE
        FROM
        SELECT
             REGEXP_SUBSTR(P_EXCEPTION_RECORD, '([^^])+', 1,t2.COLUMN_VALUE) str
        FROM
            DUAL t1 CROSS JOIN
                    TABLE
                        CAST
                            MULTISET
                                SELECT LEVEL
                                FROM DUAL
                                CONNECT BY LEVEL <= REGEXP_COUNT(P_EXCEPTION_RECORD, '([^^])+')
                            AS SYS.odciNumberList
                    ) t2
        WHERE REGEXP_SUBSTR(str,'[^|]*',1,1) IS NOT NULL
        COMMIT;
       EXCEPTION
         WHEN OTHERS THEN
         ROLLBACK;
         RAISE;
    END;
Many Thanks,
Arpit

Answer 1

Regex's are known to be CPU intensive specially when dealing with large number of rows.
If you have to reduce the processing time, you need to tune the Select statements.
One suggested change could be to change the following query
SELECT
             REGEXP_SUBSTR(P_EXCEPTION_RECORD, '([^^])+', 1,t2.COLUMN_VALUE) str
        FROM
            DUAL t1 CROSS JOIN
                    TABLE
                        CAST
                            MULTISET
                                SELECT LEVEL
                                FROM DUAL
                                CONNECT BY LEVEL <= REGEXP_COUNT(P_EXCEPTION_RECORD, '([^^])+')
                            AS SYS.odciNumberList
                    ) t2
to
SELECT REGEXP_SUBSTR(P_EXCEPTION_RECORD, '([^^])+', 1,level) str
FROM DUAL
CONNECT BY LEVEL <= REGEXP_COUNT(P_EXCEPTION_RECORD, '([^^])+')
Before looking for any performance benefit, you need to ensure that this does not change your output.
How many substrings are you expecting in the P_EXCEPTION_RECORD? If less than 5, it will be better to opt for SUBSTR and INSTR combination as it might work well with the number of records you are working with. Only trouble is, you will have to write different SUBSTR and INSTR statements for each column to be fetched.
How are you calling this procedure? Is it not possible to work with Collections? Delimited strings are not a very good option as it requires splitting of the data every time you need to refer to.