Is it possible to limit the execution time for a query?
I have an application that will run a query to gather statistics. The time window is defined by the user. Since the polling period for data collection varies, it is not possible to say that a large time window will result in a large resultSet. I may have a polling period of 1 minute or a polling period of 1 hour.
I want to avoid a user executing a query that will consume too many resources and inpact the system's performce in general. Could I stop a query after it takes more that x secs? Is there a way to write an sql statement indicating the max response time? similar to rownum?
You can also create an Oracle profile with limited resources and assign it to the Oracle account running the queries (this profile will be used for all queries run by the corresponding user). Resources can only specifed in cpu time (not elapsed time) or logical reads.
See http://download-uk.oracle.com/docs/cd/B10501_01/server.920/a96521/users.htm#15451
and http://download-uk.oracle.com/docs/cd/B10501_01/server.920/a96540/statements_611a.htm#2065932
Similar Messages
-
How to find the Execution Time for Java Code?
* Hi everyone , i want to calculate the execution time for my process in java
* The following was the ouput for my coding,
O/P:-
This run took 0 Hours ;1.31 Minutes ;78.36 Seconds
*** In the above output , the output should come exactly what hours , minutes and seconds for my process,
but in my code the minutes are converted into seconds(It should not)...
* Here is my coding,
static long start_time;
public static void startTime()
start_time = System.currentTimeMillis();
public static void endTime()
DecimalFormat df = new DecimalFormat("##.##");
long end_time = System.currentTimeMillis();
float t = end_time - start_time;
float sec = t / 1000;
float min = 0, hr = 0;
if (sec > 60) {
min = sec / 60;
if (min > 60) {
hr = min / 60;
System.out.println("This run took " + df.format(hr) + " Hours ;"+ df.format(min) + " Minutes ;" + df.format(sec) + " Seconds");
}* How to Calcualte exact timing for my process....
* Thanks* Hi flounder, Is following code will wotk perfectly?
public static void endTime()
DecimalFormat df = new DecimalFormat("##.##");
long end_time = System.currentTimeMillis();
float t = end_time - start_time;
float sec = t / 1000;
float min = 0, hr = 0;
while(sec >= 60){
min++;
sec = sec -60;
if (min >= 60){
min = 0; //or min = min -60;
hr++;
System.out.println("This run took " + df.format(hr) + " Hours ;"+ df.format(min) + " Minutes ;" + df.format(sec) + " Seconds");
} -
How to find the execution time of a query?
hi guys,
i need to find the execution time of a query.
i tried finding it in rsrt but couldn find the execution time.
pleasse let me know the way to do it..
regards
sagarHi sagar,
If you want to know the frontend time, first of all you need to maitain the BW Statistics. To maintain you have to go the respective target and click on it. Go to the tools, select BW Statistics of infoprovider. It pop ups a window there you find two check boxes 1) WHM and 2) Front end time. Check both.
Now Exe query and close the analyzer. Then go to SE11 table RSDDSTAT. There is one field which displays Frentend time.
OR
Go to STO3 here also you can analys the frontend time.
If you feel useful Assign Pts.
Regards,
Vishal -
Query Execution Time for a Query causing ORA-1555
dear Gurus
I have ORA-01555 error , earlier I used the Query Duration mentioned in Alert Log and increased the Undo Retention as I did not find th UnDOBLKS column of v$undostat high for the time of occurence of ORA-01555..
But new ORA-01555 is coming whose query duration exceeds Undo Retention time..
My question -
1. Is it possible to accurately find the query duration time besides the Alert Log file ?abhishek, as you are using an undo tablespace and have already increased the time that undo data is retained via undo_retention then you might want to consider the following ideas which were useful with 1555 error under manual rbs segment management.
1- Tune the query. The faster a query runs the less likely a 1555 will occur.
2- Look at the processing. If a process was reading and updating the same table while committing frequenctly then the process under manual rbs management would basically create its own 1555 error rather than just being the victum of another process changing data and the rbs data being overlaid while the long running query was still running. With undo management the process could be generating more data than can be held for the undo_retention period but because it is committed Oracle has been told it doesn't really have to keep the data for use rolling back a current transaction so it gets discarded to make room for new changes.
If you find item 2 is true then separating the select from the update will likely eliminate the 1555. You do this by building a driving table that has the keys of the rows to be updated or deleted. Then you use the driver to control accessing the target table.
3- If the cause of the 1555 is or may be delayed block cleanout then select * from the target prior to running the long running query.
Realistically you might need to increase the size of the undo tablespace to hold all the change data and the value of the undo_retention parameter to be longer than the job run time. Which brings up back to option 1. Tune every query in the process so that the job run time is reduced to optimal.
HTH -- Mark D Powell --
dear mark
Thanks for the excellent advise..I found that the error is coming because of frequent commits..which is item 2 as u righly mentioned ..
I think I need to keep a watch on the queries running , I was just trying to find the execution time for the queries..If there is any way to find the query duration without running a trace ..
regards
abhishek -
How to capture the execution plan for a query
HI All,
Can anyone please help me in finding out the command to capture the execution plan for a query.
Execution plan for select * from EMP where <Condtions>
it is getting executed successfully but i need to get the proper execution plan for the same.
Thanks971830 wrote:
i want to know where execution plan gets generated??
in PMON of server process or in shared pool??
i know that optimixer create execution plan..It is stored in Library Cache (present inside Shared Pool ).
select * from v$sql_plan;An absolute beautiful white paper :
Refer this -- www.sagelogix.com/sagelogix/SearchResults/SAGE015052
Also -- http://www.toadworld.com/KNOWLEDGE/KnowledgeXpertforOracle/tabid/648/TopicID/XPVSP/Default.aspx
HTH
Ranit B. -
Reduce the execution time for the below query
Hi,
Please help me to reduce the execution time on the following query .. if any tuning is possible.
I have a table A with the columns :
ID , ORG_LINEAGE , INCLUDE_IND ( -- the org lineage is a string of ID's. If ID 5 reports to 4 and 4 to 1 .. the lineage for 5 will be stored as the string -1-4-5)
Below is the query ..
select ID
from A a
where INCLUDE_IND = '1' and
exists (
select 1
from A b
where b.ID = '5'
and b.ORG_LINEAGE like '%-'||a.ID||'-%'
order by ORG_LINEAGE;
The only constraint on the table A is the primary key on the ID column.
Following will be the execution plan :
Execution Plan
0 SELECT STATEMENT Optimizer=CHOOSE (Cost=406 Card=379 Bytes=2
653)
1 0 SORT (ORDER BY) (Cost=27 Card=379 Bytes=2653)
2 1 FILTER
3 2 TABLE ACCESS (FULL) OF 'A' (Cost=24 Card
=379 Bytes=2653)
4 2 TABLE ACCESS (BY INDEX ROWID) OF 'A' (Co
st=1 Card=1 Bytes=6)
5 4 INDEX (RANGE SCAN) OF 'ORG_LINEAGE'
(NON-UNIQUE)I order it by the org_lineage to get the first person. So it is a result problem? The order by doesn't give you the first person, it gives you a sorted result set (of which there may be zero, one, or thousands).
If you only want one row from that, then you're spending a lot of time tuning the wrong query.
How do you know which ORG_LINEAGE row you want?
Maybe it would help if you posted some sample data. -
Can I reduce the execution time for a step in a TestStand ?
Hi,
I calculated the a single step execution time for TestStand Ver 2.0. It comes to around 20 milliseconds/step. Can I reduce this excution time ?
Are there any settings available for configuring execution time parameters except result logging and exception handlings to reduce the execution time ?It's difficult to tell how you what time you are reporting for your step. Clearly we don't have control of the time it takes your code to execute. However, we are constantly working on reducing the overhead of calling the code. In addition, you don't mention the type of step you are calling. One way to have a common reference is to use the example \Examples\Benchmarks\Benchmarks.seq. Below have have posted the results of running this sequence with both tracing and result collection enabled and then disabled. I have a 700 MHz, 128 MB RAM, Dell PIII laptop. In this example there is no code within the code modules. You notice that calling a DLL has the least overhead with a minimum of 7.459 ms with tracing and results enabled and 0.092 ms with tracing and results disabled. Although not included below, if I enable results be disable tracing I get a minimum time of 0.201 ms, a 100x improvement on your time.
With Results and Tracing enabled.
7.578 milliseconds per step for CVI Standard Prototype - Object File
7.579 milliseconds per step for CVI Standard Prototype - DLL
7.459 milliseconds per step for DLL Flexible Prototype
8.589 milliseconds per step for DLL Flexible Prototype Numeric Limit
9.563 milliseconds per step for DLL Flexible Prototype Numeric Limit with Precondition
10.015 milliseconds per step for DLL Flexible Prototype Numeric Limit with Precondition and 4 Parameters
7.868 milliseconds per step for ActiveX Automation
8.892 milliseconds per step for LabVIEW Standard Prototype
With tracing and results disabled.
0.180 milliseconds per step for CVI Standard Prototype - Object File
0.182 milliseconds per step for CVI Standard Prototype - DLL
0.092 milliseconds per step for DLL Flexible Prototype
0.178 milliseconds per step for DLL Flexible Prototype Numeric Limit
0.277 milliseconds per step for DLL Flexible Prototype Numeric Limit with Precondition
0.400 milliseconds per step for DLL Flexible Prototype Numeric Limit with Precondition and 4 Parameters
0.270 milliseconds per step for ActiveX Automation
1.235 milliseconds per step for LabVIEW Standard Prototype -
To Check the execution time for each transaction.
Abapers,
How to find out the process time for each transaction eg.order entry,shippng,billing, etc in SAP.
TIA,
sinthuHi,
By default you can see the execution time at right side corner of sap session.
You can use SE30 to get in to more details like database time , abap time etc...
Hope it helps...
Regards,
Vijay -
How to get the execution time of a query
Hi,
Environment: 10.2.0.4.0
Just wondering how I can get the query execution time? I am not interested in the query output nor do I want the statistics, just the execution time?
Any suggestions will be appreciated
Thanks in advance
rogers42If you're using SQL*Plus
SQL> set autotrace traceonly
SQL> set timing on
SQL> <<your query here>>SQL*Plus will fetch all the data and then report the query plan, execution statistics, and elapsed time. It will not display the actual data.
SET TIMING ON alone tells SQL*Plus to display the execution time of each SQL statement-- the problem is that it also displays all the data which can skew the results because you're including the time required by SQL*Plus to pipe a bunch of data to the screen.
Justin -
Performance Tuning -To find the execution time for Select Statement
Hi,
There is a program that takes 10 hrs to execute. I need tune its performance. The program is basically reading few tables like KNA1,ANLA,ANLU,ADRC etc and updates to Custom table. I did my analysis and found few performance techniques for ABAP coding.
Now my problem is, to get this object approved I need to submit the execution statistics to client.I checked both ST05 and SE30. I heard of a Tcode where we can execute a select statement and note its time, then modify and find its improved Performance. Can anybody suggest me on this.
Thanks,
Rajani.Hi,
This is documentation regarding performance analysis. Hope this will be useful
It is a general practice to use Select * from <database> This statement populates all the values of the structure in the database.
The effect is many fold:-
It increases the time to retrieve data from database
There is large amount of unused data in memory
It increases the processing time from work area or internal tables
It is always a good practice to retrieve only the required fields. Always use the syntax Select f1 f2 fn from <database>
e.g. Do not use the following statement:-
Data: i_mara like mara occurs 0 with header line.
Data: i_marc like marc occurs 0 with header line.
Select * from mara
Into table i_mara
Where matnr in s_matnr.
Select * from marc
Into table i_marc
For all entries in i_mara
Where matnr eq i_mara-matnr.
Instead use the following statement:-
Data: begin of i_mara occurs 0,
Matnr like mara-matnr,
End of i_mara.
Data: begin of i_marc occurs 0,
Matnr like marc-matnr,
Werks like marc-werks,
End of i_marc.
Select matnr from mara
Into table i_mara
Where matnr in s_matnr. -
I reaaally hate how anti-procrastination apps like ColdTurkey don't work for apple products, because what's the point of restricting internet usage on the computer when you can just access it from your apple device? There's no point in using the parental controls or setting passwords for obvious reasons, either.
So I had an idea: from what I know, after guessing the password incorrectly 6 times, the device is locked for 1 min, 7 times, 5 min etc. So I was thinking, is it possible to change the settings, for example, to lock the phone for 60min after 3 wrong password attempts? This would be incredibly helpful!!
(if you know a way but don't want to post it here, please email me instead!)Thanks a lot Rob. That works.
"Rob Woollen" <[email protected]> wrote in message
news:3f29b665$[email protected]..
java -Djava.io.tmpdir=<tmpdir path> weblogic.appc
-- Rob
Bernhard Lenz wrote:
I realized that weblogic.appc creates a working directory
/var/tmp/appcgen
when compiling ejbs. What happens if 2 developers run weblogic.appc atthe
same time? Will they be using the same temp directory and therefore getin
each others way? I'd rather like to create a temp directory which isunique
for the machine. Our build scripts would be able to create such adirectory
but I couldn't find anything in appc to set the temp directory.
Do you have any advice?
Thanks for your help.
Greetings
Bernie -
How to find out the execution time of a sql inside a function
Hi All,
I am writing one function. There is only one IN parameter. In that parameter, i will pass one SQL select statement. And I want the function to return the exact execution time of that SQL statement.
CREATE OR REPLACE FUNCTION function_name (p_sql IN VARCHAR2)
RETURN NUMBER
IS
exec_time NUMBER;
BEGIN
--Calculate the execution time for the incoming sql statement.
RETURN exec_time;
END function_name;
/Please note that wrapping query in a "SELECT COUNT(*) FROM (<query>)" doesn't necessarily reflect the execution time of the stand-alone query because the optimizer is smart and might choose a completely different execution plan for that query.
A simple test case shows the potential difference of work performed by the database:
Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production
Session altered.
SQL>
SQL> drop table count_test purge;
Table dropped.
Elapsed: 00:00:00.17
SQL>
SQL> create table count_test as select * from all_objects;
Table created.
Elapsed: 00:00:02.56
SQL>
SQL> alter table count_test add constraint pk_count_test primary key (object_id)
Table altered.
Elapsed: 00:00:00.04
SQL>
SQL> exec dbms_stats.gather_table_stats(ownname=>null, tabname=>'COUNT_TEST')
PL/SQL procedure successfully completed.
Elapsed: 00:00:00.29
SQL>
SQL> set autotrace traceonly
SQL>
SQL> select * from count_test;
5326 rows selected.
Elapsed: 00:00:00.10
Execution Plan
Plan hash value: 3690877688
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 5326 | 431K| 23 (5)| 00:00:01 |
| 1 | TABLE ACCESS FULL| COUNT_TEST | 5326 | 431K| 23 (5)| 00:00:01 |
Statistics
1 recursive calls
0 db block gets
419 consistent gets
0 physical reads
0 redo size
242637 bytes sent via SQL*Net to client
4285 bytes received via SQL*Net from client
357 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
5326 rows processed
SQL>
SQL> select count(*) from (select * from count_test);
Elapsed: 00:00:00.00
Execution Plan
Plan hash value: 572193338
| Id | Operation | Name | Rows | Cost (%CPU)| Time |
| 0 | SELECT STATEMENT | | 1 | 5 (0)| 00:00:01 |
| 1 | SORT AGGREGATE | | 1 | | |
| 2 | INDEX FAST FULL SCAN| PK_COUNT_TEST | 5326 | 5 (0)| 00:00:01 |
Statistics
1 recursive calls
0 db block gets
16 consistent gets
0 physical reads
0 redo size
412 bytes sent via SQL*Net to client
380 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
1 rows processed
SQL>As you can see the number of blocks processed (consistent gets) is quite different. You need to actually fetch all records, e.g. using a PL/SQL block on the server to find out how long it takes to process the query, but that's not that easy if you want to have an arbitrary query string as input.
Regards,
Randolf
Oracle related stuff blog:
http://oracle-randolf.blogspot.com/
SQLTools++ for Oracle:
http://www.sqltools-plusplus.org:7676/
http://sourceforge.net/projects/sqlt-pp/ -
Estimate execution time for CTAS
Hi,
I am searching for long to find a way to estimate the execution time for CTAS commands. I am a DBA. Our users run CTAS commands to load millions of rows. The commands fetch data from 4-5 very big tables each with millions of records and process them using where clause and group by clause and finally create the table. All these things are coded in the CTAS command. These CTAS sometime takes long time like 5 , 8 Hrs. Users frequently ask me to find how long it's going to take. I use both OEM and TOAD. But I couldn't find the time estimated from these tools. I feel that there must be some way, but I don't know the method.
Can any body please help me in this regard?
Thanks & Regards
Ananda BasakIt depends on a number of factors chief among them how accurate your estimate needs to be but also including things like what version of Oracle you're using, how accurate your database statistics are, etc.
One option is to look at the TIME column in the plan. For example, if I wanted to do a CTAS to create a copy of the EMP table, the optimizer expects that to take on the order of a second. Of course, the optimizer's estimates are only estimates and are only as accurate as the database statistics that are in place. If the optimizer generates a bad plan, it's likely because the optimizer expects some operation to take much more or much less time than it does in reality in which case the optimizer's runtime estimate is likely to be way off.
SQL> explain plan for create table emp_copy as select * from emp;
Explained.
SQL> ed
Wrote file afiedt.buf
1 select *
2* from table( dbms_xplan.display() )
SQL> /
PLAN_TABLE_OUTPUT
Plan hash value: 2748781111
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
| 0 | CREATE TABLE STATEMENT | | 14 | 546 | 4 (0)| 00:00:01 |
| 1 | LOAD AS SELECT | EMP_COPY | | | | |
| 2 | TABLE ACCESS FULL | EMP | 14 | 546 | 3 (0)| 00:00:01 |
-----------------------------------------------------------------------------------Depending on the query plan, you may be able to query the GV$SESSION_LONGOPS table to track the progress of any long-running operations in your session. If your query plan involves a lot of full table scans, sorts that take more than a few seconds, hash joins, etc. then it is likely that you'll be able to chart the progress of a query over time by watching GV$SESSION_LONGOPS change. Of course, if your query is going to need to do many long-running operations, you'll need to a human to interpret the data a bit in order to figure out where in the plan Oracle currently is and how far along that means the entire query is.
SELECT *
FROM gv$session_longops
WHERE time_remaining > 0If you're using 11g and you have the performance and tuning pack licensed, you could also potentially use the V$SQL_PLAN_MONITOR view.
Justin -
TO REDUCE THE EXECUTION TIME OF REPORT
HI,
CAN ANYONE TELL ME THAT, HOW CAN I REDUCE THE EXECUTION TIME OF THE REPORT. IS THERE ANY IDEA TO IMPROVE THE PERFORMANCE OF THE REPORT.Hi Santosh,
Good check out the following documentation
<b>Performance tuning</b>
For all entries
Nested selects
Select using JOINS
Use the selection criteria
Use the aggregated functions
Select with view
Select with index support
Select Into table
Select with selection list
Key access to multiple lines
Copying internal tables
Modifying a set of lines
Deleting a sequence of lines
Linear search vs. binary
Comparison of internal tables
Modify selected components
Appending two internal tables
Deleting a set of lines
Tools available in SAP to pin-point a performance problem
<b>Optimizing the load of the database</b>
For all entries
The for all entries creates a where clause, where all the entries in the driver table are combined with OR. If the number of entries in the driver table is larger than rsdb/max_blocking_factor, several similar SQL statements are executed to limit the length of the WHERE clause.
The plus
Large amount of data
Mixing processing and reading of data
Fast internal reprocessing of data
Fast
The Minus
Difficult to program/understand
Memory could be critical (use FREE or PACKAGE size)
Some steps that might make FOR ALL ENTRIES more efficient:
Removing duplicates from the the driver table
Sorting the driver table
If possible, convert the data in the driver table to ranges so a BETWEEN statement is used instead of and OR statement:
FOR ALL ENTRIES IN i_tab
WHERE mykey >= i_tab-low and
mykey <= i_tab-high.
Nested selects
The plus:
Small amount of data
Mixing processing and reading of data
Easy to code - and understand
The minus:
Large amount of data
when mixed processing isnt needed
Performance killer no. 1
Select using JOINS
The plus
Very large amount of data
Similar to Nested selects - when the accesses are planned by the programmer
In some cases the fastest
Not so memory critical
The minus
Very difficult to program/understand
Mixing processing and reading of data not possible
Use the selection criteria
SELECT * FROM SBOOK.
CHECK: SBOOK-CARRID = 'LH' AND
SBOOK-CONNID = '0400'.
ENDSELECT.
SELECT * FROM SBOOK
WHERE CARRID = 'LH' AND
CONNID = '0400'.
ENDSELECT.
Use the aggregated functions
C4A = '000'.
SELECT * FROM T100
WHERE SPRSL = 'D' AND
ARBGB = '00'.
CHECK: T100-MSGNR > C4A.
C4A = T100-MSGNR.
ENDSELECT.
SELECT MAX( MSGNR ) FROM T100 INTO C4A
WHERE SPRSL = 'D' AND
ARBGB = '00'.
Select with view
SELECT * FROM DD01L
WHERE DOMNAME LIKE 'CHAR%'
AND AS4LOCAL = 'A'.
SELECT SINGLE * FROM DD01T
WHERE DOMNAME = DD01L-DOMNAME
AND AS4LOCAL = 'A'
AND AS4VERS = DD01L-AS4VERS
AND DDLANGUAGE = SY-LANGU.
ENDSELECT.
SELECT * FROM DD01V
WHERE DOMNAME LIKE 'CHAR%'
AND DDLANGUAGE = SY-LANGU.
ENDSELECT.
Select with index support
SELECT * FROM T100
WHERE ARBGB = '00'
AND MSGNR = '999'.
ENDSELECT.
SELECT * FROM T002.
SELECT * FROM T100
WHERE SPRSL = T002-SPRAS
AND ARBGB = '00'
AND MSGNR = '999'.
ENDSELECT.
ENDSELECT.
Select Into table
REFRESH X006.
SELECT * FROM T006 INTO X006.
APPEND X006.
ENDSELECT
SELECT * FROM T006 INTO TABLE X006.
Select with selection list
SELECT * FROM DD01L
WHERE DOMNAME LIKE 'CHAR%'
AND AS4LOCAL = 'A'.
ENDSELECT
SELECT DOMNAME FROM DD01L
INTO DD01L-DOMNAME
WHERE DOMNAME LIKE 'CHAR%'
AND AS4LOCAL = 'A'.
ENDSELECT
Key access to multiple lines
LOOP AT TAB.
CHECK TAB-K = KVAL.
ENDLOOP.
LOOP AT TAB WHERE K = KVAL.
ENDLOOP.
Copying internal tables
REFRESH TAB_DEST.
LOOP AT TAB_SRC INTO TAB_DEST.
APPEND TAB_DEST.
ENDLOOP.
TAB_DEST[] = TAB_SRC[].
Modifying a set of lines
LOOP AT TAB.
IF TAB-FLAG IS INITIAL.
TAB-FLAG = 'X'.
ENDIF.
MODIFY TAB.
ENDLOOP.
TAB-FLAG = 'X'.
MODIFY TAB TRANSPORTING FLAG
WHERE FLAG IS INITIAL.
Deleting a sequence of lines
DO 101 TIMES.
DELETE TAB_DEST INDEX 450.
ENDDO.
DELETE TAB_DEST FROM 450 TO 550.
Linear search vs. binary
READ TABLE TAB WITH KEY K = 'X'.
READ TABLE TAB WITH KEY K = 'X' BINARY SEARCH.
Comparison of internal tables
DESCRIBE TABLE: TAB1 LINES L1,
TAB2 LINES L2.
IF L1 <> L2.
TAB_DIFFERENT = 'X'.
ELSE.
TAB_DIFFERENT = SPACE.
LOOP AT TAB1.
READ TABLE TAB2 INDEX SY-TABIX.
IF TAB1 <> TAB2.
TAB_DIFFERENT = 'X'. EXIT.
ENDIF.
ENDLOOP.
ENDIF.
IF TAB_DIFFERENT = SPACE.
ENDIF.
IF TAB1[] = TAB2[].
ENDIF.
Modify selected components
LOOP AT TAB.
TAB-DATE = SY-DATUM.
MODIFY TAB.
ENDLOOP.
WA-DATE = SY-DATUM.
LOOP AT TAB.
MODIFY TAB FROM WA TRANSPORTING DATE.
ENDLOOP.
Appending two internal tables
LOOP AT TAB_SRC.
APPEND TAB_SRC TO TAB_DEST.
ENDLOOP
APPEND LINES OF TAB_SRC TO TAB_DEST.
Deleting a set of lines
LOOP AT TAB_DEST WHERE K = KVAL.
DELETE TAB_DEST.
ENDLOOP
DELETE TAB_DEST WHERE K = KVAL.
Tools available in SAP to pin-point a performance problem
The runtime analysis (SE30)
SQL Trace (ST05)
Tips and Tricks tool
The performance database
Optimizing the load of the database
Using table buffering
Using buffered tables improves the performance considerably. Note that in some cases a stament can not be used with a buffered table, so when using these staments the buffer will be bypassed. These staments are:
Select DISTINCT
ORDER BY / GROUP BY / HAVING clause
Any WHERE clasuse that contains a subquery or IS NULL expression
JOIN s
A SELECT... FOR UPDATE
If you wnat to explicitly bypass the bufer, use the BYPASS BUFFER addition to the SELECR clause.
Use the ABAP SORT Clause Instead of ORDER BY
The ORDER BY clause is executed on the database server while the ABAP SORT statement is executed on the application server. The datbase server will usually be the bottleneck, so sometimes it is better to move thje sort from the datsbase server to the application server.
If you are not sorting by the primary key ( E.g. using the ORDER BY PRIMARY key statement) but are sorting by another key, it could be better to use the ABAP SORT stament to sort the data in an internal table. Note however that for very large result sets it might not be a feasible solution and you would want to let the datbase server sort it.
Avoid ther SELECT DISTINCT Statement
As with the ORDER BY clause it could be better to avoid using SELECT DISTINCT, if some of the fields are not part of an index. Instead use ABAP SORT + DELETE ADJACENT DUPLICATES on an internal table, to delete duplciate rows.
Good Luck and thanks
AK -
How can I get the elapse time for execution of a Query for a session
Hi ,
How can I get the elapse time for execution of a Query for a session?
Example - I have a report based on the procedure ,when the user execute that it takes say 3 min. to return rows.
Is there any possible way to capture this session info. for this particular execution of query along with it's execution elapse time?
Thanks in advance.Hi
You can use the dbms_utility.get_time tool (gives binary_integer type value).
1/ Initialize you time and date of beginning :
v_beginTime := dbms_utility.get_time ;
2/ Run you procedure...
3/ Get end-time with :
v_endTime := dbms_utility.get_time ;
4/ Thus, calculate elapsed time by difference :
v_elapsTime := v_endTime - v_beginTime ;
This will give you time elapsed in of 100th of seconds...
Then you can format you result to give correct print time.
Hope it will help you.
AL
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