Re: Weird Oracle 12.2 issue ..
Date: Fri, 15 Sep 2017 07:35:27 +0000
Message-ID: <BN6PR1001MB2162C9B86A69E89C110C2C06D86C0_at_BN6PR1001MB2162.namprd10.prod.outlook.com>
It is true that we are using LOBs, but the main question is, why does this query runs faster when it is run directly on the DB server vs run through a client?
Is there a relationship between the LOB data and the latency we are seeing?
Here is the description of the function call:
FUNCTION GET_DESC_LIST RETURNS VARCHAR2
Argument Name Type In/Out Default? ------------------------------ ----------------------- ------ -------- P_DESC_ID NUMBER IN FUNCTION GET_DESC_LIST RETURNS VARCHAR2 Argument Name Type In/Out Default? ------------------------------ ----------------------- ------ -------- P_DESC_ID NUMBER IN P_CLIENT_ID NUMBER IN
_at_Peter, I put in the sqlnet.ora parameter, i didn't see any difference between the executions.
-Upendra
From: Sayan Malakshinov <xt.and.r_at_gmail.com> Sent: Friday, September 15, 2017 2:50 AM To: pgr_at_miracle.dk
Cc: Upendra nerilla; Oracle-L
Subject: Re: Weird Oracle 12.2 issue ..
Upendra,
I've just checked your trace file for LOBS:
$ grep -c LOBREAD rcaqa_ora_27261.trc
590
$ awk -F, '/LOBREAD/ {print $2}' rcaqa_ora_27261.trc | sort | uniq
bytes=25
bytes=80
Could you show what returns the function aep_i18n.get_desc_list? Execute "desc aep_i18n.get_desc_list" in sql*plus and send us the output of this command.
Also you can try the following query - I've split allFields0 into 2 columns: allFields0_varchar is for short strings(as varchar2)
select
SERVICE_NAME
,ID
,DESCRIPTION_ID
,case when length("allFields0")<=4000 then cast("allFields0" as varchar2(4000)) end "allFields0_varchar"
,case when length("allFields0")>4000 then "allFields0" end "allFields0_CLOB"
from (
select /*+NO_XML_QUERY_REWRITE*/
AES_REC_TYPE.SERVICE_NAME SERVICE_NAME,
AES_REC_TYPE.ID<http://AES_REC_TYPE.ID> ID,
aep_i18n.get_desc_list(AES_REC_TYPE.DESCRIPTION_ID, AES_REC_TYPE.CLIENT_ID) "DESCRIPTION_ID",
(SELECT (xmlelement("_fieldType",
xmlagg(xmlelement("allFields",
xmlforest(AES_FLD_TYPE.SERVICE_NAME SERVICE_NAME0, AES_FLD_TYPE.ID<http://AES_FLD_TYPE.ID> ID0, aep_i18n.get_desc_list(AES_FLD_TYPE.DESCRIPTION_ID, AES_REC_TYPE.CLIENT_ID) "DESCRIPTION_ID0",
aep_attributes.fetch_attr(AES_FLD_TYPE.ID<http://AES_FLD_TYPE.ID>, 'AES_FLD_TYPE', 'COLUMN_NAME', AES_REC_TYPE.CLIENT_ID) "COLUMN_NAME",
aep_attributes.fetch_attr(AES_FLD_TYPE.ID<http://AES_FLD_TYPE.ID>, 'AES_FLD_TYPE', 'BI_COLUMN_NAME', AES_REC_TYPE.CLIENT_ID) "BI_COLUMN_NAME"))))).getClobVal()
FROM AES_FLD_TYPE AES_FLD_TYPE
WHERE AES_REC_TYPE.ID<http://AES_REC_TYPE.ID> = AES_FLD_TYPE.REC_TYPE_ID
AND AES_FLD_TYPE.DELETED_DATE IS NULL
AND AES_REC_TYPE.client_id = AES_FLD_TYPE.client_id) "allFields0"
FROM AES_REC_TYPE AES_REC_TYPE
WHERE AES_REC_TYPE.DELETED_DATE IS NULL
AND AES_REC_TYPE.CLIENT_ID = 12313400144 )
/
On Fri, Sep 15, 2017 at 9:19 AM, Peter Gram Miracle A/S <pgr_at_miracle.dk<mailto:pgr_at_miracle.dk>> wrote: Hi
Try setting tcp.nodelay=yes in the sqlnet.ora on the client just to make surer you are not bite by that.
Gram/
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On 15 September 2017 at 01:17, Upendra nerilla <nupendra_at_hotmail.com<mailto:nupendra_at_hotmail.com>> wrote:
All,
We are running into a unique issue.. We recently migrated a database from 11.2 to 12.2 for testing.
When we compared the performance, 12.2 performance was 3x-4x slow compared to 11g.
When we were peeling the layers to troubleshoot, we discovered:
- A query which runs in 3 seconds at the database directly (in 12.2) takes between 11-14 seconds when it is run through a client like pl/sql developer.
- To eliminate the variables, we ran sqlplus from another host (which is in same network), and the execution time was still over 13 seconds.
- sqlplus on the DB server (using tns/sqlnet) produces the result in about 3 seconds as well
- Sysadmin says, Network throughput between the servers have no issue, he was able to scp a 500MB file in less than 2 seconds.
Here is the output from SQL trace.. the output from running the query from the DB server and through the client produce identical output, except the elapsed time..
<snip>
583 rows selected.
Elapsed: 00:00:02.51 vs Elapsed: 00:00:11.44
Execution Plan
Plan hash value: 2598178018
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time | ------------------------------------------------------------------------------------------------------------ | 0 | SELECT STATEMENT | | 1220 | 56120 | 1244 (0)| 00:00:01 | | 1 | SORT AGGREGATE | | 1 | 47 | | | |* 2 | TABLE ACCESS BY INDEX ROWID BATCHED| AES_FLD_TYPE | 1 | 47 | 2 (0)| 00:00:01 | |* 3 | INDEX RANGE SCAN | AES_IDX_FTYPE_RTYPE | 1 | | 1 (0)| 00:00:01 | |* 4 | TABLE ACCESS FULL | AES_REC_TYPE | 1220 | 56120 | 24 (0)| 00:00:01 | ------------------------------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
2 - filter("AES_FLD_TYPE"."DELETED_DATE" IS NULL)
3 - access("AES_FLD_TYPE"."REC_TYPE_ID"=:B1 AND "AES_FLD_TYPE"."CLIENT_ID"=:B2)
4 - filter("AES_REC_TYPE"."DELETED_DATE" IS NULL AND "AES_REC_TYPE"."CLIENT_ID"=12313400144<tel:(231)%20340-0144>)
Statistics
66503 recursive calls
0 db block gets
71151 consistent gets
0 physical reads
0 redo size
382206 bytes sent via SQL*Net to client
248383 bytes received via SQL*Net from client
1168 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
583 rows processed
<snip>
Any suggestions on what I could check to pin-point the issue might be helpful..
Thanks in advance
-Upendra
-- Best regards, Sayan Malakshinov Oracle performance tuning engineer Oracle ACE Associate http://orasql.org -- http://www.freelists.org/webpage/oracle-lReceived on Fri Sep 15 2017 - 09:35:27 CEST