Should we use Subquery caching or result cache here
From: Lok P <loknath.73_at_gmail.com>
Date: Sat, 30 Oct 2021 01:13:37 +0530
Message-ID: <CAKna9VavDSbaSQ1T_8rzH-rBF5XRx+Nw_O7M_FNuG2tHvQjCmQ_at_mail.gmail.com>
Hello Listers, We have below Insert query which is executed ~50k - 60K times each day. And this is consuming major amount of time in a specific process/procedure which in turns gets called from multiple scenarios. And while looking into the sql monitor we saw its majorly CPU time and its in the loading part only(~350 secs), which seems to be coming from the function call in the SELECT part of the insert query. As shown in the sql monitor this function seems to be getting called atleast ~8million times here one time for each row for this single execution of the main insert query. I have posted the function code here below. So in total this function call seems to be happening billions of time in a day. Its oracle database version 19.9.0.0.0. I never used but heard of few option in such cases like scalar subquery caching, Result cache, deterministic function etc. So wanted to understand, if wrapping up this function call in a "select from dual" i.e utilizing scalar subquery caching technique will help us here? Or as the function body doesn't depend on any DB tables etc, a results cache should be opted here? What should be the best option here?
FROM RTFX RTFX, RFFT RFFT, ND ND, RDC RDC WHERE RTFX.FFXID = RFFT.FXID
ELSIF (INBK = 'X')
THEN
END IF;
RETURN 0;
END;
/
| Elapsed | Cpu | IO | Concurrency | Cluster | PL/SQL | Other |
Buffer | Read | Read |
| Time(s) | Time(s) | Waits(s) | Waits(s) | Waits(s) | Time(s) | Waits(s)
| Gets | Reqs | Bytes |
| 742 | 704 | 35 | 0.17 | 0.00 | 157 | 3.07 |
11M | 67661 | 529MB |
Date: Sat, 30 Oct 2021 01:13:37 +0530
Message-ID: <CAKna9VavDSbaSQ1T_8rzH-rBF5XRx+Nw_O7M_FNuG2tHvQjCmQ_at_mail.gmail.com>
Hello Listers, We have below Insert query which is executed ~50k - 60K times each day. And this is consuming major amount of time in a specific process/procedure which in turns gets called from multiple scenarios. And while looking into the sql monitor we saw its majorly CPU time and its in the loading part only(~350 secs), which seems to be coming from the function call in the SELECT part of the insert query. As shown in the sql monitor this function seems to be getting called atleast ~8million times here one time for each row for this single execution of the main insert query. I have posted the function code here below. So in total this function call seems to be happening billions of time in a day. Its oracle database version 19.9.0.0.0. I never used but heard of few option in such cases like scalar subquery caching, Result cache, deterministic function etc. So wanted to understand, if wrapping up this function call in a "select from dual" i.e utilizing scalar subquery caching technique will help us here? Or as the function body doesn't depend on any DB tables etc, a results cache should be opted here? What should be the best option here?
We have currently having below result cache option as i see in v$parameter.
NAME VALUE
result_cache_mode MANUAL result_cache_max_size 107380736 result_cache_max_result 5 result_cache_remote_expiration 0 client_result_cache_size 0 client_result_cache_lag 3000
*Main query:-*
INSERT INTO GLBL_TMP_TBL1 (.........)
SELECT............
pkg.fun1 (RFFT.AMT, RTFX.STS, RTFX.PDT, :B1, ( :B1 + 1),
'X'),
pkg.fun1 (RFFT.AMT, RTFX.STS, RTFX.PDT, :B1, ( :B1 + 1), 'Y'),
TRUNC ( :B1)....
FROM RTFX RTFX, RFFT RFFT, ND ND, RDC RDC WHERE RTFX.FFXID = RFFT.FXID
AND RTFX.AC_Key = RFFT.C_Key
AND RFFT.CT_Key = ND.N_Key
AND ND.N_ETY IN ('XX', 'YY', 'ZZ')...;
*Function code:- *
FUNCTION fun1(INAMT IN NUMBER, INSTS IN VARCHAR2, INPDT IN
DATE,IN_STDT IN DATE, IN_ENDT IN DATE, INBK IN VARCHAR2) RETURN
NUMBER IS
o_pdt DATE;
BEGIN
IF INBK = 'Y' THEN
IF (INSTS = 'AA' AND INPDT > IN_ENDT) THEN
RETURN INAMT ;
END IF;
IF (INSTS IN ('SS','BB', 'TT','ZZ')) THEN
RETURN INAMT ;
END IF;
ELSIF (INBK = 'X')
THEN
IF to_char(INPDT, 'HH:MI:SS AM') = '12:00:00 AM' then SELECT TO_DATE(TO_CHAR(INPDT,'MM/DD/YYYY') || ' ' ||TO_CHAR(IN_STDT, 'HH:MI:SS AM'), 'MM/DD/YYYY HH:MI:SS AM') INTO o_pdt FROM DUAL;
ELSE
o_pdt := INPDT;
END IF;
IF (INSTS = 'AA' AND o_pdt >= IN_STDT AND o_pdt < IN_ENDT)
THEN
DBMS_OUTPUT.PUT_LINE(o_pdt || ' - ' || INAMT);
RETURN INAMT ;
END IF;
END IF;
RETURN 0;
END;
/
Global Information
STATUS : DONE Instance ID : 4 SQL Execution ID : 67303461 Execution Started : 10/29/2021 07:03:58 First Refresh Time : 10/29/2021 07:04:02 Last Refresh Time : 10/29/2021 07:16:19 Duration : 741s
Global Stats
| Elapsed | Cpu | IO | Concurrency | Cluster | PL/SQL | Other |
Buffer | Read | Read |
| Time(s) | Time(s) | Waits(s) | Waits(s) | Waits(s) | Time(s) | Waits(s)
| Gets | Reqs | Bytes |
| 742 | 704 | 35 | 0.17 | 0.00 | 157 | 3.07 |
11M | 67661 | 529MB |
SQL Plan Monitoring Details (Plan Hash Value=3120541595)
| Id | Operation | Name
| Rows | Cost | Time | Start | Execs | Rows | Read | Read |
Activity | Activity Detail |
| | |
| (Estim) | | Active(s) | Active | | (Actual) | Reqs |
Bytes | (%) | (# samples) |
======================================================================================================================================================================================================================
| 0 | INSERT STATEMENT |
| | | 738 | +4 | 1 | 0 | |
| 20.82 | Cpu (152) |
| 1 | LOAD TABLE CONVENTIONAL | GLBL_TMP_TBL1
| | | 741 | +1 | 1 | 0 | |
| 32.33 | Cpu (236) |
| 2 | NESTED LOOPS |
| 115 | 86999 | 738 | +4 | 1 | 8M | |
| 0.27 | Cpu (2) |
| 3 | NESTED LOOPS |
| 115 | 86999 | 738 | +4 | 1 | 8M | |
| | |
| 4 | NESTED LOOPS |
| 115 | 86884 | 738 | +4 | 1 | 8M | |
| 0.27 | Cpu (2) |
| 5 | NESTED LOOPS |
| 4405 | 82363 | 738 | +4 | 1 | 8M | |
| | |
| 6 | TABLE ACCESS STORAGE FULL | RTFX
| 3291 | 14 | 738 | +4 | 1 | 4250 | |
| | |
| 7 | PARTITION LIST ITERATOR |
| 1 | 25 | 738 | +4 | 4250 | 8M | |
| | |
| 8 | TABLE ACCESS BY LOCAL INDEX ROWID BATCHED | RFFT
| 1 | 25 | 738 | +4 | 4249 | 8M | 55950 |
437MB | 5.48 | Cpu (11) |
| | |
| | | | | | | |
| | cell single block physical read (29) |
| 9 | INDEX RANGE SCAN | RFFT_IX1
| 836 | 4 | 738 | +4 | 4249 | 8M | 9331 | 73MB
| 1.37 | Cpu (5) |
| | |
| | | | | | | |
| | cell single block physical read (5) |
| 10 | TABLE ACCESS BY INDEX ROWID BATCHED | ND
| 1 | 2 | 738 | +4 | 8M | 8M | |
| 3.15 | Cpu (23) |
| 11 | INDEX RANGE SCAN | ND_IX6
| 1 | 1 | 738 | +4 | 8M | 8M | |
| 2.74 | Cpu (20) |
| 12 | INDEX UNIQUE SCAN | RDC_PK
| 1 | | 742 | +0 | 8M | 8M | |
| 0.55 | Cpu (4) |
| 13 | TABLE ACCESS BY INDEX ROWID | RDC
| 1 | 1 | 738 | +4 | 8M | 8M | |
| 3.15 | Cpu (23) |
======================================================================================================================================================================================================================
-- http://www.freelists.org/webpage/oracle-lReceived on Fri Oct 29 2021 - 21:43:37 CEST