1 million rows average row length 200 bytes 50 columns and this update statement UPDATE mytable SET varchar2_4000_column = replace(replace(replace...300 times)
It looks at every row in the table (no WHERE clause) and does these 300 replace operations on this column for each row. Each replace replaces with a null so effectively it is removing strings. Much of the time these strings are not in the column.
This update statement takes 25 minutes and it is 98% CPU and 2% USER_IO time.
I figure that is what is taking all the time since it is a CPU bound statement. if rows in this table are persistent over time then tag rows with a flag to show which ones have already been processed and skip these next time around.
I have Created sequence in oracle 10G and its working fine. its showing THE NUMBER IS 2
SQL> DECLARE NUM NUMBER; 2 BEGIN 3 select SERIAL_NO.NEXTVAL into num from dual; 4 DBMS_OUTPUT.PUT_LINE('THE NUMBER IS ' ||NUM); 5 END; 6 / THE NUMBER IS 2
PL/SQL procedure successfully completed.When i execute this code in oracle 11G then it does not show output.
SQL> DECLARE NUM NUMBER; 2 BEGIN 3 NUM :=SERIAL_NO.NEXTVAL; 4 DBMS_OUTPUT.PUT_LINE('THE NUMBER IS ' ||NUM); 5 END; 6 /
PL/SQL procedure successfully completed. SQL> Why this is not showing output as THE NUMBER IS .
Predicate Information (identified by operation id): ---------------------------------------------------
4 - access("A"."DEPTNO"="B"."DEPTNO")
Nested loop by defintion means,for every row returned by the outer query,the inner query is executed that many times.
In the above example,oracle does a full table scan and returned 14 rows.Now for dept table,it does a index unique scan and applies the predicate a.deptno=b.deptno and returns 1 row.
My question is why it is returning only 1 row? That measn for every 14 rows,this one row is fetched 14 times.
I want to make sure I am describing correctly what happens in a query where there is distributed database access and it is participating in a NESTED LOOPS JOIN. Below is an example query, the query plan output, and the remote SQL information for such a case. Of particular note are line#4 (NESTED LOOPS) and line#11 (REMOTE TABLE_0002).
What I want to know is more detail on how this NESTED LOOPS JOIN handles the remote operation. For example, for each row that comes out of line#5 and is thus going into the NESTED LOOPS JOIN operation @line#4, does the database jump across the network to do the remote loopkup? Thus if there are 1 million rows, does that mean 1 million network hops? Does batchsize play a role? For example, if the database batches in groups of 100 then does that mean 10 thousand network hops?
I think each row that comes out of line#5 means a network hop to the remote database. But I do not know for a fact.I have done some abbreviating in the plan in an attempt to make it fit on the page (line#7 TA = TABLE ACCESS).
explain plan for select count(*) from orders, lineitem where o_orderkey= l_orderkey.
The trace 10053 (as shown below) for this query shows nested loop join with Lineitem as outer table and Orders as inner table. It is effectively join on composite index (pk_lineitem) of Lineitem and unique index(Pk_orderkey) of Orders table. The cost calculation formula as given in the book as "outer table cost + cardinality of outer table * inner table cost " fails here. I am not able to understand this.
BANNER ---------------------------------------------------------------- Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bi PL/SQL Release 10.2.0.4.0 - Production CORE 10.2.0.4.0 Production TNS for Solaris: Version 10.2.0.4.0 - Production NLSRTL Version 10.2.0.4.0 - Production
5 rows selected.
I have a problem with views and nested selects which I cannot explain. Here is a trimed down version of the research I have done. notice the following:
1) all code is executed from the same user CDRNORMALCODE. this user has all views and procedural code 2) all data is owned by a different user CDRDATA. This user has no views and no code.
My problem is this:
If I reference the table directly with a delete statement that uses a nested select (i.e. IN clause with select), the index I expect and want is used.But if I execute the same delete but reference even the most simple of views (select * from <table>) instead of the table itself, then a full table scan is done of the table.
Here is an execute against the table directly (owned by cdrdata). Notice the reference to the table in the table schema on line 3. Also please notice INDEX RANGE SCAN BSNSS_CLSS_CASE_RULE_FK1 at the bottom of the plan.
SQL> show user USER is "CDRNORMALCODE" SQL> SQL> explain plan for 2 delete
[code]...
OK, here is an update. The views I am useing normally have instead of triggers on them. If I remove the instead of trigger the problem looks like it goes away, when I put the trigger back the problem comes back.But why would an instead-of-trigger change the query plan for a view?
SQL> DELETE FROM PLAN_TABLE;
5 rows deleted.
SQL> explain plan for 2 delete 3 from BSNSS_CLSS_MNR_CASE_RULE_SV
I'm joinging two tables event_types and tmp_acc tables.
event_types contains 2 Billion records tmp_acc contains 20,000 records.
Resulting rows are about 300,000 records in event_types table end_t and account_obj_id0 are joined indexed
no indexs in tmp_acc.
When I run below query with nexted loop it takes 6 hrs to complete. But when I run with hash join even after 4 days it was still running. what is wrong with hash join here. Why it takes so long. I'm joining only 20000 rows. So I think there should be a way to get result rows quickly.
show parameters hash_area_size
NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ hash_area_size integer 2097152
explain plan for select --+ parallel(e,6) [code]....
I want to know how the Oracle optimizer choose joins and apply them while executing the query. So that I will insure about optimizer join before writing any query.
Table 1 include members of a certain club with specific criteria Table 2 needs to include everyone else on the main database, not in the club, but with the same criteria.
So, ultimate goal is to have two tables, similar criteria, T1 = club members and T2 = non-club members
Table 1 ran just fine.
Table 2 is running and running and running. I'm looking for a more efficient way then the syntax below:
create table NON_club_Members nologging as select distinct hcp.ID, count (distinct hcp.profile_key) from mrtcustomer.table_1 hcp, Club_Members cm where hcp.child_birth_dt between '31-OCT-2000' and '30-OCT-2011' and hcp.ID not in (select cm.id from Club_Members) group by hcp.id
I've also tried <> and that also ran and ran and ran.
im used to using PL SQL via oracle. but lately ive been doing a lot of mysql and PHP and i really need to use something similar to DECODE in my queries. or am i forced to do the checks via PHP.
I have been told that I cannot use Oracle directory objects, external tables and the UTL_FILE package in my production environment for security reasons.
In this scenario what are the alternate options available in Oracle to write a file and save it in a specific location in the server. One of my requirement is to process a file and write the results of processing in a output file in the application server which in turn will be accessed by the online application.
For whatever reason, in PHP, DESC statements do not work. They're simply unrecognized and you get an OCI "invalid SQL statement" error. It may be some sort of security feature. I've also had the same result with the SQL scratchpad in the Java EM, but not in SQL Plus. Is there an alternative method for getting details on a table that I can use that also doesn't require being logged in as a SYSDBA?
an alternative to Oracle Cursors.My table has huge amount of data and is taking time in processing. I had thought of using BULK COLLECT but it can only be used to insert, delete or update data and will not allow me to select data.
Is there any alternative of Soundex function. I have two table of city. I want to compare city of both table. Now problem is that one city name is 'HANGO'. In table A City is feed with spelling 'HANGO' and other it is spelled 'HANGU' OR 'HUNGU'. Similarly there are many cases. I used Soundex function but it is not working perfectly.
I'm trying to group sets of data based on time separations between records and then count how many records are in each group.
In the example below, I want to return the count for each group of data, so Group 1=5, Group 2=5 and Group 3=5
SELECT AREA_ID AS "AREA ID", LOC_ID AS "LOCATION ID", TEST_DATE AS "DATE", TEST_TIME AS "TIME" FROM MON_TEST_MASTER WHERE AREA_ID =89 AND LOC_ID ='3015' AND TEST_DATE ='10/19/1994';
[code]....
Group 1 = 8:00:22 to 8:41:22
Group 2 = 11:35:47 to 11:35:47
Group 3 = 15:13:46 to 15:13:46
Keep in mind the times will always change, and sometime go over the one hour mark, but no group will have more then a one hour separation between records.
Many moons ago, at a previous employer, I had access to the SQL Monitor tool that came with TOAD. I could really use an alternative to this now, as we don't have TOAD here, and it would need to be free. I'm getting a problem with a forms update failing, and I really need to see what's actually being submitted to the database by the form. We're still stuck on Forms 6 by the way
I have the following query but it is taking too much time because of the LEFT OUTER JOIN on HST table which is a huge table , is there an alternative to LEFT OUTER JOIN that can be used to optimize the code:
I read that rownum is applied after the selection is made and before "order by". So, in order to get the sum of salaries for all employees in all departments with a row number starting from 1, i wrote :
select ROWNUM,department_id,sum(salary) from employees group by department_id
If i remove rownum, it gives the correct output. Why can't rownum be used here ?
My clients want to print the output of reports of size 25*12 and 15*12 in 11g and I am able to do the printing but the page break required for each page is not coming properly and because of this they cannoy identify which is the 1st and 2nd paper..
But in 6i D2K, there is the Live Previewer through which I can print without any page break issues.
My query is what is the alternative for Live previewer in Oracle Reports 11g so that i can make it right.
Any alternative to filer the Initial using a single REGEXP_REPLACE ? Oracle version 10.2.xxxx
Currently using two REGEXP_REPLACEs. SELECT REGEXP_REPLACE( REGEXP_REPLACE('K I Rajuvan K I', '(([[:upper:]]{1,2})) ','') , '([[:upper:]]{1,2})$','') CITY FROM dual;
I'm using apex 4.1 and create a page with Interactive report with one default primary report and several default alternative report. when i selected one alternative report, how do i know which one is i picked up? it looks obvious to the user but my point is when the user switches to another page, or there are something should change based on the selected report, i want the user see the new page with-in the context of what have selected for that IR report. for example, i have a "summary" report based on year, so the alternative report will be year-2011, year-2012, etc, when user selected this year, 2012, on the same IR page, there is another report based on year 2012, when user selected 2011, that report should show 2011 report.
/* Step2 Create MATERIALIZED VIEW Refresh after Every 20 Minutes */ CREATE MATERIALIZED VIEW MV_ABC REFRESH FAST START WITH SYSDATE NEXT SYSDATE+20/ (24*60) AS SELECT * FROM ABC WHERE TMSTP > SYSDATE-1;
Scenario:Intially data extracted will be "Greater than SYSDATE-1 = 18/08/2009 11:27:39 " - 76 Millions of Records After 20 Min of FAST Refresh, it will add 2500 Records
i)Is query in the MVIEWS (MV_ABC) SYSDATE-1 will be changed on each FAST Refresh, as observation (as per definition) it is incrementing the records to intial extracted data?
ii)As COMPLETE Refresh will be expensive to execute on the partition base table on each refresh. Is there any alternative way to achieve the Nature of COMPLETE REFRESH in Materialized View?
iii)Is Delete or Conditional Delete option is possible in Materialized View (i.e not a delete from the base table but the delete from MVIEWS)?
iv)What is the machnism for populating the logs for MVIEWS?Is it overhead for the system and better than a Trigger based approach?
