Query Performance Issue
Date: Tue, 23 Apr 2019 17:38:15 +0530
Message-ID: <CAOGpvWpuZFLsvNGQyp2Czn1509fP0kp_=nH3Ks+YQ-XwJDW+WQ_at_mail.gmail.com>
Hi All,
I have a query where in application has a read timeout set for 20 seconds.
SELECT COUNT (DISTINCT U.USER_KEY) FROM TMS.USERS U JOIN TMS.USER_GROUP UG ON U.USER_KEY = UG.USER_KEY WHERE UG.GROUP_TREE_KEY = 'ia744d7790000015b347a4749dd5889b8' and UG.delete_flag ='N' and U.delete_flag ='N';
With most bind values of group_tree_key the query runs within 20 seconds. But with GROUP_TREE_KEY having more number of records in TMS.USER_GROUP the query runs for more than 20 seconds and then application fails with "Socket Read Timeout".
Below are few details related to table stats and column stats. There is huge skewness in data for GROUP_TREE_KEY for the table TMS.USER_GROUP. I tried to collect the column stats for the table TMS.USER_GROUP for the column GROUP_TREE_KEY but that didn't have much effect. Is there any way we can optimize the query to have a better run time?
TMS.USER_GROUP DETAILS
OWNER TABLE_NAME LAST_ANALYZED NUM_ROWS ------------------------------ ------------------------------TABLE_NAME COLUMN_NAME INDEX_NAME COLUMN_POSITION --------------------------- --------------------------- ------------------------------------ --------------- USER_GROUP USER_KEY XPKUSER_GROUP 1 USER_GROUP GROUP_TREE_KEY XPKUSER_GROUP 2 USER_GROUP START_DATE XPKUSER_GROUP 3 USER_GROUP STOP_DATE XPKUSER_GROUP 4 USER_GROUP GROUP_TREE_KEY UG_FK_GROUPKEY 1 USER_GROUP USER_KEY UG_USER_KEY 1 USER_GROUP UPDATED_TIMESTAMP USER_GROUP_IDX 1
----------------------------- ----------
TMS USER_GROUP 01-FEB-2019 23:21:25 55479760 OWNER TABLE_NAME COLUMN_NAME NUM_DISTINCT NUM_BUCKETS HISTOGRAM ------------------------------ ------------------------------ ------------------------------ ------------ ----------- --------------- TMS USER_GROUP UPDATED_TIMESTAMP 2851921 1 NONE TMS USER_GROUP STOP_DATE 4166 1 NONE TMS USER_GROUP START_DATE 3301 1 NONE TMS USER_GROUP GROUP_TREE_KEY 87351 1 NONE TMS USER_GROUP USER_KEY 2112700 1 NONE TMS USER_GROUP DELETE_FLAG 2 1 NONE
7 rows selected.
OWNER INDEX_NAME LAST_ANALYZED NUM_ROWS NUM_ROWS CLUSTERING_FACTOR ------------------------------ ------------------------------------
----------------------------- ---------- ---------- -----------------
TMS XPKUSER_GROUP 01-FEB-2019 23:23:32 55821380 55821380 50385340 TMS UG_FK_GROUPKEY 01-FEB-2019 23:24:36 56195400 56195400 11056540 TMS UG_USER_KEY 01-FEB-2019 23:25:55 55064620 55064620 45906520 TMS USER_GROUP_IDX 01-FEB-2019 23:26:54 55041170 55041170 15547360
TMS.USERS DETAILS
OWNER TABLE_NAME LAST_ANALYZED
NUM_ROWS
------------------------------ ---------------------------
----------------------------- ----------
TMS USERS 16-APR-2019 23:23:18
4093040
OWNER TABLE_NAME COLUMN_NAME
NUM_DISTINCT NUM_BUCKETS HISTOGRAM
------------------------------ ---------------------------
--------------------------- ------------ ----------- ---------------
TMS USERS ENCRYPTED_PASSWORD
0 0 NONE
TMS USERS DISABLE_GRP_IPR
1 1 NONE
TMS USERS NEW_USER
2 1 NONE
TMS USERS IP_RESTRICTED
1 1 NONE
TMS USERS REASON_CODE_KEY
4 1 NONE
TMS USERS LOGIN_LIMIT
3 1 NONE
TMS USERS SHARED
1 1 NONE
TMS USERS USER_PWD_CLUE
0 0 NONE
TMS USERS STOP_DATE
111803 1 NONE
TMS USERS START_DATE
289426 1 NONE
TMS USERS INACTIVE_STATE
1 1 NONE
TMS USERS DOMAIN_KEY
1 1 NONE
TMS USERS FAILED_LOGIN_CNT
52 1 NONE
TMS USERS PWD_EXPIRED
1 1 NONE
TMS USERS USER_GUID
4093040 1 NONE
TMS USERS USER_CREATE_DATE
426536 1 NONE
TMS USERS USER_LASTMOD_DATE
596781 1 NONE
TMS USERS USER_PWD_RESPONSE
0 0 NONE
TMS USERS USER_PWD_CHALLENGE
0 0 NONE
TMS USERS USER_EMAIL
26162 1 NONE
TMS USERS USER_ID
4093040 1 NONE
TMS USERS USER_PASSWORD
2479152 1 NONE
TMS USERS USER_MIDDLE_NAME
0 0 NONE
TMS USERS USER_FIRST_NAME
11933 1 NONE
TMS USERS USER_LAST_NAME
33227 1 NONE
TMS USERS USER_KEY
4093040 1 NONE
TMS USERS DELETE_FLAG
2 1 NONE
TMS USERS SYS_NC00027$
1000 1 NONE
TABLE_NAME COLUMN_NAME INDEX_NAME
COLUMN_POSITION
--------------------------- ---------------------------
------------------------------------ ---------------
USERS USER_KEY XPKUSER
1
USERS USER_GUID PSU_USER_GUID_IDX
1
USERS USER_ID
PSU_USER_ID_DOM_UQ_IDX 1
USERS DOMAIN_KEY
PSU_USER_ID_DOM_UQ_IDX 2
USERS DOMAIN_KEY PSU_DKEY_EMAIL
1
USERS USER_EMAIL PSU_DKEY_EMAIL
2
USERS INACTIVE_STATE PSU_INACTIVE_STATE
1
USERS REASON_CODE_KEY XIF5USER
1
USERS SYS_NC00027$ MOD_IDX
1
9 rows selected.
OWNER INDEX_NAME LAST_ANALYZED NUM_ROWS NUM_ROWS CLUSTERING_FACTOR ------------------------------ ------------------------------------
----------------------------- ---------- ---------- -----------------
TMS XPKUSER 16-APR-2019 23:23:18 4237790 4237790 1774550 TMS PSU_USER_GUID_IDX 16-APR-2019 23:23:19 4001180 4001180 1689690 TMS PSU_USER_ID_DOM_UQ_IDX 16-APR-2019 23:23:19 3900400 3900400 1994620 TMS PSU_DKEY_EMAIL 16-APR-2019 23:23:27 4268590 4268590 275130 TMS PSU_INACTIVE_STATE 16-APR-2019 23:23:27 8694 8694 6123 TMS XIF5USER 16-APR-2019 23:23:27 8840 8840 6337 TMS MOD_IDX 16-APR-2019 23:23:31 3972540 3972540 3902610
I understand all details are not supplied however, I am ready to get that if asked for.,
Thanks,
Rakesh RA
-- http://www.freelists.org/webpage/oracle-lReceived on Tue Apr 23 2019 - 14:08:15 CEST
- text/plain attachment: GUID_USER_GROUP.txt