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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Long-running SQL
Cherie - This means that on the average the query is retrieving 366 values?
I had something similar on our data warehouse. Indexed retrievals and full
table scans took about the same amount of time. I ended up partitioning the
table on that key and the queries flew. Interestingly enough, the weekly
loads were speeded up by a magnitude.
Dennis Williams
DBA
Lifetouch, Inc.
dwilliams_at_lifetouch.com
-----Original Message-----
Sent: Wednesday, March 27, 2002 10:40 AM
To: Multiple recipients of list ORACLE-L
Lisa,
I'm not positive that it is actually using the index. This load ran last night so I was not able to trace as it happened. Following is the explain plan that Precise monitoring tool states that it should have used:
Count (stopkey)
Table access (by index rowid) EDM_DBO.EXP_COST_CENTER_DIM
Index (range scan) EDM_DBO.EXP_COST_CENTER_DIM_IDX1
If I have to, I will get up tonight and do a trace.
There are 998 unique values for account number column out of about 365,000 rows.
This statement has always been bad and caused problems for the load. Since
I could never recommend
an improvement for it, I just looked at other things. However, the
nightly loads have been running outside
the window now with an increase in amount of data loaded and things are now
at a crisis point.
Thanks,
Cherie
"Koivu, Lisa"
<lisa.koivu_at_efair To: "'ORACLE-L_at_fatcity.com'"
<ORACLE-L_at_fatcity.com>,
field.com> "'cherie_machler_at_gelco.com'"
<cherie_machler_at_gelco.com>
cc:
03/27/02 10:16 AM Subject: RE: Long-running
SQL
Hi Cherie,
do you know for sure it is using the index? Have you traced it? Can you
post the explain plan? What's the cardinality of account_number in this
table?
I can just hear those people over there screaming at you saying it's your problem...
Lisa Koivu
Oracle Database Administrator
Fairfield Resorts, Inc.
954-935-4117
> -----Original Message-----
> From: Cherie_Machler_at_gelco.com [SMTP:Cherie_Machler_at_gelco.com]
> Sent: Wednesday, March 27, 2002 9:33 AM
> To: Multiple recipients of list ORACLE-L
> Subject: Long-running SQL
>
>
> We have a statement that I feel takes too long to run in a nightly data
> load.
> The table it runs against has 386,000 records. It runs for about 10
> seconds
> on average. We're only loading about 50,000 records a night but this
> statement
> is running during the majority of the 9-hour load time. This is causing
> the
> load to run longer than our allowable window and causing me untold
> headaches.
> If anyone has any suggestions to make this run faster, I'd be greatly
> appreciative.
>
> The columns in the where statement are all part of an index. However,
> the functions on the columns add additional execution time and
complexity.
>
> This is an 8.0.4 database so I can not make this a function-based index.
>
> I put this in a couple of SQL tuning tools and came up with no valid
> alternatives.
> I can't help thinking that the statement could be rewritten into a couple
> of statements
> so that it would be more efficient. However, I'm not skilled enough
with
> SQL to
> do it. Perhaps someone else is. Here's the code.
>
> SELECT /*+ INDEX(EXP_COST_CENTER_DIM EXP_COST_CENTER_DIM_IDX1) + */
> EXP_COST_CENTER_KEY
> FROM EXP_COST_CENTER_DIM
>
> WHERE ACCOUNT_NUMBER = :b1 AND
> NVL(ORG_LEVEL_1_VALUE,'NONE') = NVL(:b2,'NONE') AND
> NVL(ORG_LEVEL_2_VALUE,'NONE') = NVL(:b3,'NONE') AND
> NVL(ORG_LEVEL_3_VALUE,'NONE') = NVL(:b4,'NONE') AND
> NVL(ORG_LEVEL_4_VALUE,'NONE') = NVL(:b5,'NONE') AND
> NVL(ORG_LEVEL_5_VALUE,'NONE') = NVL(:b6,'NONE') AND
> NVL(ORG_LEVEL_6_VALUE,'NONE') = NVL(:b7,'NONE') AND
> NVL(ORG_LEVEL_7_VALUE,'NONE') = NVL(:b8,'NONE') AND
> NVL(ORG_LEVEL_8_VALUE,'NONE') = NVL(:b9,'NONE') AND
> ROWNUM = 1
>
>
> SQL> desc exp_cost_center_dim
> Name Null? Type
> ------------------------------- -------- ----
> EXP_COST_CENTER_KEY NOT NULL NUMBER(7)
> ACCOUNT_NUMBER NOT NULL NUMBER(9)
> BATCH_WINDOW_DATE_KEY NOT NULL NUMBER(5)
> ORG_LEVEL_1_VALUE VARCHAR2(20)
> ORG_LEVEL_2_VALUE VARCHAR2(20)
> ORG_LEVEL_3_VALUE VARCHAR2(20)
> ORG_LEVEL_4_VALUE VARCHAR2(20)
> ORG_LEVEL_5_VALUE VARCHAR2(20)
> ORG_LEVEL_6_VALUE VARCHAR2(20)
> ORG_LEVEL_7_VALUE VARCHAR2(20)
> ORG_LEVEL_8_VALUE VARCHAR2(20)
> DATA_SOURCE_MOD_DATETIME NOT NULL DATE
> DATA_WAREHOUSE_MOD_DATETIME NOT NULL DATE
> DATA_MART_MOD_DATETIME NOT NULL DATE
>
>
> SQL> select column_name from dba_ind_columns where index_name
> ='EXP_COST_CENTER_D
> IM_IDX1';
>
> COLUMN_NAME
>
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: INET: Cherie_Machler_at_gelco.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: DENNIS WILLIAMS INET: DWILLIAMS_at_LIFETOUCH.COM Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Wed Mar 27 2002 - 11:15:22 CST
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