Poor performance when using bind variable in report

I have a report that takes 1 second to run if i 'hardcode' a particular value into the where clause of the report. However, if i now replace the hardcoded value with a bind variable and set the default value for the bind variable to be the (previous) hard coded value the report now takes 50 seconds to run instead of 1 second!!
Has anyone else seen this behaviour - any suggestions to workaround this will be gratefully received

More info
SELECT patch_no, count(*) frequency
FROM users_requests
WHERE patchset IN (SELECT arps2.patchset_name
FROM aru_bugfix_relationships abr, aru_bugfixes ab, aru_status_codes ac,
aru_patchsets arps, aru_patchsets arps2
WHERE arps.patchset_name = '11i.FIN_PF.E'
AND abr.bugfix_id = ab.bugfix_id
AND arps.bugfix_id = ab.bugfix_id
AND abr.relation_type = ac.status_id
AND arps2.bugfix_id = abr.related_bugfix_id
AND abr.relation_type IN (601, 602))
AND included ='Y'
GROUP BY patch_no
order by frequency desc, patch_no
Runs < 1 sec from SQL navigator and from portal (if i hardcode the value for fampack.
Takes ~50 secs if i replace with :fampack and set default value to 11i.FIN_PF.D

Similar Messages

Performance when using bind variables

I'm trying to show myself that bind variables improve performance (I believe it, I just want to see it).
I've created a simple table of 100,000 records each row a single column of type integer. I populate it with a number between 1 and 100,000
Now, with a JAVA program I delete 2,000 of the records by performing a loop and using the loop counter in my where predicate.
My first JAVA program runs without using bind variables as follows:
loop
stmt.executeUpdate("delete from nobind_test where id = " + i);
end loop
My second JAVA program uses bind variables as follows:
pstmt = conn.prepareStatement("delete from bind_test where id = ?");
loop
pstmt.setString(1, String.valueof(i));
rs = pstmt.executeQuery();
end loop;
Monitoring of v$SQL shows that program one doesn't use bind variables, and program two does use bind variables.
The trouble is that the program that does not use bind variables runs faster than the bind variable program.
Can anyone tell me why this would be? Is my test too simple?
Thanks.

[email protected] wrote:
I'm trying to show myself that bind variables improve performance (I believe it, I just want to see it).
I've created a simple table of 100,000 records each row a single column of type integer. I populate it with a number between 1 and 100,000
Now, with a JAVA program I delete 2,000 of the records by performing a loop and using the loop counter in my where predicate.
Monitoring of v$SQL shows that program one doesn't use bind variables, and program two does use bind variables.
The trouble is that the program that does not use bind variables runs faster than the bind variable program.
Can anyone tell me why this would be? Is my test too simple?
The point is that you have to find out where your test is spending most of the time.
If you've just populated a table with 100,000 records and then start to delete randomly 2,000 of them, the database has to perform a full table scan for each of the records to be deleted.
So probably most of the time is spent scanning the table over and over again, although most of blocks might already be in your database buffer cache.
The difference between the hard parse and the soft parse of such a simple statement might be negligible compared to effort it takes to fulfill each delete execution.
You might want to change the setup of your test: Add a primary key constraint to your test table and delete the rows using this primary key as predicate. Then the time it takes to locate the row to delete should be negligible compared to the hard parse / soft parse difference.
You probably need to increase your iteration count because deleting 2,000 records this way probably takes too short and introduces measuring issues. Try to delete more rows, then you should be able to spot a significant and constant difference between the two approaches.
In order to prevent any performance issues from a potentially degenerated index due to numerous DML activities, you could also just change your test case to query for a particular column of the row corresponding to your predicate rather than deleting it.
Regards,
Randolf
Oracle related stuff blog:
http://oracle-randolf.blogspot.com/
SQLTools++ for Oracle (Open source Oracle GUI for Windows):
http://www.sqltools-plusplus.org:7676/
http://sourceforge.net/projects/sqlt-pp/

What's disadvantages when using bind variables always in java?

Hello everyone .. Could someone tell me what's the disadvantage when using bind variable in java ? I heard it somecases since before.. Thanks in advance!

99% of the time, you should be using bind variables. If you have columns which are highly skewed, however, you may want to consider using literals (assuming CURSOR_SHARING=EXACT), since that may allow the CBO to make a better decision.
If you have an orders table, for example, you may have a status column that specifies whether the order is complete, in transit, or new. If you've been running for a while, 99% of your orders will be complete, so
SELECT COUNT(*)
FROM orders
WHERE status = :1should do a full table scan if you specify 'COMPLETE'. If you passed in 'IN TRANSIT', though, an index scan might be more appropriate. If you want to pass in different values and get different query plans, you need to use literals. 99% of the time, though, you want the same plan, so you want to use bind variables.
Justin
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC

Possible for Oracle to consider constraints when using bind variable?

Consider the following table with a check constraint listing the possible values of the column
create table TEST_TABLE(
my_column varchar2(10));
insert into TEST_TABLE select 'VALUE1' from dba_objects;
alter table TEST_TABLE
add constraint TEST_TABLE_CHK1
check (my_column in ('VALUE1', 'VALUE2'));
begin dbms_stats.gather_table_stats(ownname=>user,tabname=>'TEST_TABLE');END;Let's see the number of logical I/O's needed for the following SQL statements.
(The value was obtained by the delta ofselect m.value from v$mystat m, v$statname n
where name='session logical reads' and m.statistic#=n.statistic#)
If string lateral is used:
declare
   n number;
begin
select count(*) into n from test_table where my_column='VALUE1';
end;
Consistent Gets: 21
declare
   n number;
begin
select count(*) into n from test_table where my_column='VALUE2';
end;
Consistent Gets: 21
declare
   n number;
begin
select count(*) into n from test_table where my_column='VALUE3';
end;
Consistent Gets: 0Oracle can eliminate the table if it knows the queried value can't satisfy the constraint. Good.
(Actually, the execution plan for the last query included the 'FILTER' operation.)
However, if bind variable is used:
declare
   n number;
   x varchar2(10);
begin
x := 'VALUE1';
select count(*) into n from test_table where my_column=x;
end;
Consistent Gets: 21
declare
   n number;
   x varchar2(10);
begin
x := 'VALUE3';
select count(*) into n from test_table where my_column=x;
end;
Consistent Gets: 21Oracle can't eliminate the table using the constraint. I can understand that because bind variables are used, Oracle can't directly eliminate the table when generating the execution plan. However, is it possible to eliminate the table, or at least employ some shortcut in runtime? If not, will this be a performance loss compared with using values laterals when check constraint exists?
(And is it possible to use autotrace on PL/SQL block in sqlplus?)
Oracle:
     10.2.0.4 SE
     11.2.0.2 SE
OS:
     RHEL5

However, is it possible to eliminate the table, or at least employ some shortcut in runtime? I can't see how to do this. Oracle has a sqltext that has an embedded bind variable in it. And for this sqltext it has an execution plan in the shared pool that will be used irrespective of the actual bound values at runtime.
Maybe in 11G, with adaptive cursor sharing / plan bind awareness, Oracle might be smart enough to introduce a second execution plan for the VALUE3 case.
If not, will this be a performance loss compared with using values laterals when check constraint exists?Only if you submit the dumb query and search for records with VALUE3... Normally your application code would not hold/generate these queries.
Will it?
For columns whose values are bound by a CHECK constraint, one might even consider to never use bind variables, since very likely you will have few versions of queries that use these columns.
Not?
Edited by: Toon Koppelaars on Jun 22, 2011 1:20 PM

Csv no data found when using bind variables

Hi,
I have created a report, that uses 2 date variables to limit the query and rows display as they should. But clicking the csv link opens csv having one row stating 'No data found...'. If I set static values in place of variables, I get the right result. How could I use bind variables and get the right answer in csv (without coding my own function)?
Kaja

I am having the same problem.
The export link opens a new session without submitting the current page. The page item values are therefor not saved to cache before the export is undertaken.
Any report using page item bind variables in the where clause will not export correctly as the bind values are either null or those of the previous page submit.
Any ideas on how to get round this??

Query don't use the right index when using bind variables

Hi people !
I need some help because I have an issue with a query that don t use the right Indexes as it should
First of all, I have mainly three tables :
ORDER : Table that contains description for each Order (approximately 1 000 000 Records)
ORDER_MVTS : Table that contains the tasks made (called movements) to set up each Orders
with quantity of packages prepared for each product (approximately 10 000 000 Records)
PRODUCT : Tables that contains the products (approximately 50 000 Records)
When I launch the query with hard coded values, it brings back response very fast
because it uses the right index (ORDER_DHR_VALID) which represent the date and hour of the order
(with format 'DD/MM/YYYY HH24:MI:SS'). The selectivity for this index is good.
NB 1: I have to use the trick " >= Trunc(date) and < trunc(date) +1 " to filter on a simple date because
the index contains hour and minutes (I know it wasn't probably a bright idea at conception time).
NB 2: The index on ORDER_MVTS.PRODUCT_CODE is'nt discriminating enough because there is'nt enough different products.
It's the same for index on CUSTOMER_CODE and on MVT_TYPE so only the index on ORDER.DHR_VALID is good.
Here is the correct explain plan when I execute the query with hard coded values :
SELECT SUM(ORDER_MVTS.NB_PACKAGE)
FROM ORDER_MVTS, PRODUCT, ORDER
WHERE ORDER.DHR_VALID >= TRUNC(to_date('14/11/2008 10:04:56','DD/MM/YYYY HH24:MI:SS'))
AND ORDER.DHR_VALID < TRUNC(to_date('14/11/2008 10:04:56','DD/MM/YYYY HH24:MI:SS')) + 1
AND ORDER_MVTS.MVT_TYPE = 'DELIVERY'
AND PRODUCT.CODE = ORDER_MVTS.PRODUCT_CODE
AND ORDER_MVTS.ORDER_CODE = ORDER.CODE
AND ORDER.CUSTOMER_CODE = 'ADIDAS'
AND PRODUCT.CODE = 1234
Rows Row Source Operation
1 SORT AGGREGATE
2 NESTED LOOPS
4 NESTED LOOPS
2 INDEX UNIQUE SCAN (object id 378548) --> PRODUCT_PK
4 TABLE ACCESS BY INDEX ROWID ORDER
777 INDEX RANGE SCAN (object id 378119) --> ORDER_DHR_VALID
2 TABLE ACCESS BY INDEX ROWID ORDER_MVTS
30 INDEX RANGE SCAN (object id 377784) --> ORDER_MVTS_ORDER_FK
Now the problem is when the query is used in a Cursor with bind variables.
It seems like Oracle don't use index on ORDER.DHR_VALID because he can't figure out that he have
to actually filter on a short period of time (only one day).
So Oracle uses the index on ORDER_MVTS.PRODUCT_CODE which is'nt a bright idea (it takes 10 secondes instead of just one)
Here is the bad explain plan :
Rows Row Source Operation
1 SORT AGGREGATE
2 NESTED LOOPS
722 NESTED LOOPS
2 INDEX UNIQUE SCAN (object id 378548) --> PRODUCT_PK
722 TABLE ACCESS BY INDEX ROWID ORDER_MVTS
1790 INDEX RANGE SCAN (object id 377777) --> ORDER_MVTS_PRODUCT_FK
2 TABLE ACCESS BY INDEX ROWID ORDER
1442 INDEX UNIQUE SCAN (object id 378439) --> ORDER_PK
Now I have found two solutions to this problem :
1) using a Hint to force the use of index on ORDER.DHR_VALID (with /*+ INDEX(ORDER ORDER_DHR_VALID) */ )
2) Using Dynamic SQL and keeping the date hard coded (but not the other values except mvt_type)
For example :
QUERY :=
'SELECT SUM(ORDER_MVTS.NB_PACKAGE)
FROM ORDER_MVTS, PRODUCT, ORDER
WHERE ORDER.DHR_VALID >= TRUNC(TO_DATE('''||To_char(P_DTE_VAL,'DD/MM/YYYY')||''',''DD/MM/YYYY'')) '||
AND ORDER.DHR_VALID < TRUNC(TO_DATE('''||To_char(P_DTE_VAL,'DD/MM/YYYY')||''',''DD/MM/YYYY'')) + 1 '||
AND ORDER_MVTS.MVT_TYPE = 'DELIVERY'
AND PRODUCT.CODE = ORDER_MVTS.PRODUCT_CODE
AND ORDER_MVTS.ORDER_CODE = ORDER.CODE
AND ORDER.CUSTOMER_CODE = :CUSTOMER
AND PRODUCT.CODE = :CODE ';
These two solutions work but Number 1 is bad in theory because it uses a Hint
and Number 2 may be difficult to code.
So my question is : Does someone knows another solution to force the use of index ORDER_DHR_VALID that can be simple and reliable.
Thank you very much for support
Edited by: remaï on Apr 1, 2009 4:08 PM

What version of oracle you have? CBO work is different in 9i and 10g.
Usually cost based optimizer do not want to use index for >< condition with binding variables because optimizer can not use statistic to determine selectivity, and by default selectivity of <> operators is low.
(As I remember '>' selectivity by default is 5%, you have two conditions > and <, therefore resulting selectivity will be 0.05*0.05=0.0025 as two independent events, but selectivity of other conditions
ORDER_MVTS.MVT_TYPE = 'DELIVERY' or ORDER.CUSTOMER_CODE = 'ADIDAS' looks much better for CBO)
The best solution I see is do not use binding variables. Actually your query looks as searching query, which executes not so often, therefore you will not have perfomance win along of skipping execution plan creation.
Edited by: JustasVred on Apr 1, 2009 10:10 AM

Query taking too long when using bind variable

Hi All,
There is a query in our prod DB which runs very slow (approx 2 hours) when it uses Bind Variables (using JDBC thin client), and when i try passing the variable using TOAD/SQL developer it runs fine.
Explain Plan for running Query
SELECT STATEMENT ALL_ROWSCost: 146 Bytes: 379 Cardinality: 1
     21 SORT ORDER BY Cost: 146 Bytes: 379 Cardinality: 1
          20 NESTED LOOPS Cost: 145 Bytes: 379 Cardinality: 1
               17 HASH JOIN Cost: 22 Bytes: 42,558 Cardinality: 123
                    15 MERGE JOIN CARTESIAN Cost: 15 Bytes: 8,910 Cardinality: 27
                         12 FILTER
                              11 NESTED LOOPS OUTER Cost: 9 Bytes: 316 Cardinality: 1
                                   8 NESTED LOOPS OUTER Cost: 8 Bytes: 290 Cardinality: 1
                                        5 NESTED LOOPS Cost: 6 Bytes: 256 Cardinality: 1
                                             2 TABLE ACCESS BY GLOBAL INDEX ROWID TABLE GDP.GDP_FX_DEALS_INCREMENTOR Cost: 4 Bytes: 28 Cardinality: 1 Partition #: 9 Partition access computed by row location
                                                  1 INDEX RANGE SCAN INDEX GDP.GDP_FX_DEALS_INC_IDX_01 Cost: 3 Cardinality: 1
                                             4 TABLE ACCESS BY INDEX ROWID TABLE GDP.GDP_FX_DEALS Cost: 2 Bytes: 228 Cardinality: 1
                                                  3 INDEX UNIQUE SCAN INDEX (UNIQUE) GDP.GDP_FX_DEALS_KEY Cost: 1 Cardinality: 1
                                        7 TABLE ACCESS BY INDEX ROWID TABLE GDP.GDP_FX_DEALS Cost: 2 Bytes: 34 Cardinality: 1
                                             6 INDEX UNIQUE SCAN INDEX (UNIQUE) GDP.GDP_FX_DEALS_KEY Cost: 1 Cardinality: 1
                                   10 TABLE ACCESS BY INDEX ROWID TABLE GDP.GDP_COUNTERPARTIES Cost: 1 Bytes: 26 Cardinality: 1
                                        9 INDEX UNIQUE SCAN INDEX (UNIQUE) GDP.PK_CPTY Cost: 0 Cardinality: 1
                         14 BUFFER SORT Cost: 14 Bytes: 448 Cardinality: 32
                              13 TABLE ACCESS FULL TABLE GDP.GDP_CITIES Cost: 6 Bytes: 448 Cardinality: 32
                    16 TABLE ACCESS FULL TABLE GDP.GDP_AREAS Cost: 6 Bytes: 2,304 Cardinality: 144
               19 TABLE ACCESS BY INDEX ROWID TABLE GDP.GDP_PORTFOLIOS Cost: 1 Bytes: 33 Cardinality: 1
                    18 INDEX UNIQUE SCAN INDEX (UNIQUE) GDP.PORTFOLIOS_KEY Cost: 0 Cardinality: 1
Explain Plan for Slow Query
Plan
SELECT STATEMENT ALL_ROWSCost: 11,526,226 Bytes: 119,281,912 Cardinality: 314,728
     21 SORT ORDER BY Cost: 11,526,226 Bytes: 119,281,912 Cardinality: 314,728
          20 HASH JOIN Cost: 11,510,350 Bytes: 119,281,912 Cardinality: 314,728
               2 TABLE ACCESS BY INDEX ROWID TABLE GDP.GDP_PORTFOLIOS Cost: 1,741 Bytes: 177,540 Cardinality: 5,380
                    1 INDEX FULL SCAN INDEX (UNIQUE) GDP.PORTFOLIOS_KEY Cost: 14 Cardinality: 5,380
               19 HASH JOIN Cost: 11,507,479 Bytes: 87,932,495,360 Cardinality: 254,140,160
                    3 TABLE ACCESS FULL TABLE GDP.GDP_AREAS Cost: 6 Bytes: 2,304 Cardinality: 144
                    18 MERGE JOIN CARTESIAN Cost: 11,506,343 Bytes: 18,602,733,930 Cardinality: 56,371,921
                         15 FILTER
                              14 HASH JOIN RIGHT OUTER Cost: 3,930,405 Bytes: 556,672,868 Cardinality: 1,761,623
                                   5 TABLE ACCESS BY INDEX ROWID TABLE GDP.GDP_COUNTERPARTIES Cost: 6,763 Bytes: 892,580 Cardinality: 34,330
                                        4 INDEX FULL SCAN INDEX (UNIQUE) GDP.PK_CPTY Cost: 63 Cardinality: 34,330
                                   13 HASH JOIN OUTER Cost: 3,923,634 Bytes: 510,870,670 Cardinality: 1,761,623
                                        10 HASH JOIN Cost: 2,096,894 Bytes: 450,975,488 Cardinality: 1,761,623
                                             7 TABLE ACCESS BY GLOBAL INDEX ROWID TABLE GDP.GDP_FX_DEALS_INCREMENTOR Cost: 2,763 Bytes: 52,083,248 Cardinality: 1,860,116 Partition #: 14 Partition access computed by row location
                                                  6 INDEX RANGE SCAN INDEX GDP.GDP_FX_DEALS_INC_IDX_01 Cost: 480 Cardinality: 334,821
                                             9 TABLE ACCESS BY INDEX ROWID TABLE GDP.GDP_FX_DEALS Cost: 1,734,205 Bytes: 8,320,076,820 Cardinality: 36,491,565
                                                  8 INDEX FULL SCAN INDEX (UNIQUE) GDP.GDP_FX_DEALS_KEY Cost: 104,335 Cardinality: 39,200,838
                                        12 TABLE ACCESS BY INDEX ROWID TABLE GDP.GDP_FX_DEALS Cost: 1,733,836 Bytes: 1,331,145,696 Cardinality: 39,151,344
                                             11 INDEX FULL SCAN INDEX (UNIQUE) GDP.GDP_FX_DEALS_KEY Cost: 104,335 Cardinality: 39,200,838
                         17 BUFFER SORT Cost: 11,499,580 Bytes: 448 Cardinality: 32
                              16 TABLE ACCESS FULL TABLE GDP.GDP_CITIES Cost: 4 Bytes: 448 Cardinality: 32
How can I avoid that.
Thanks

Hello
Could you reformat your execution plans because they aren't particularly readable. The forums allow you to preserve the formatting of code or output by putting the symbol {noformat}{noformat} before and after the section of text you want to preserve formatting for.
If you write
{noformat}select * from v$version
{noformat}
it will be displayed asselect * from v$version
So can you run this above statement and post the output here so we know the full oracle version you are working with? And finally, it would be really helpful to see the query you are running. When you say it runs fine in Toad, is that when you replace the bind variables with the values or are you also using bind variables in Toad?
Cheers
David

Poor performance when using kde desktop effect

Hey,
I'm having trouble when using kde effet (system settings -> desktop -> desktop effects).
I have a dual core E5200 3 ghz, 2 GB memory pc8500 and an HD4850 using fglrx driver, but I got incredible bad performance when using desktop effect and watching video, I can barely watch a 800x600 video in full screen mode without having bad performance, X getting up to 40% cpu usage.
Its really like my graphic card isnt handling the rendering stuff but 3D acceleration is working, I can play 3D game without problem so far (as long as the deskstop effect arent enabled cause the cpu have like a hard time handling both for recent game)
So I guess its some trouble with 2D acceleration or something like that, I read that some people had such issue, but I didnt figure a way to fix it.
Here is my xorg.conf, in case something is wrong with it :
Section "ServerLayout"
Identifier "X.org Configured"
Screen 0 "aticonfig-Screen[0]-0" 0 0
InputDevice "Mouse0" "CorePointer"
InputDevice "Keyboard0" "CoreKeyboard"
EndSection
Section "Files"
ModulePath "/usr/lib/xorg/modules"
FontPath "/usr/share/fonts/misc"
FontPath "/usr/share/fonts/100dpi:unscaled"
FontPath "/usr/share/fonts/75dpi:unscaled"
FontPath "/usr/share/fonts/TTF"
FontPath "/usr/share/fonts/Type1"
EndSection
Section "Module"
Load "dri2"
Load "extmod"
Load "dbe"
Load "record"
Load "glx"
Load "dri"
EndSection
Section "InputDevice"
Identifier "Keyboard0"
Driver "kbd"
EndSection
Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/input/mice"
Option "ZAxisMapping" "4 5 6 7"
EndSection
Section "Monitor"
Identifier "Monitor0"
VendorName "Monitor Vendor"
ModelName "Monitor Model"
EndSection
Section "Monitor"
Identifier "aticonfig-Monitor[0]-0"
Option "VendorName" "ATI Proprietary Driver"
Option "ModelName" "Generic Autodetecting Monitor"
Option "DPMS" "true"
EndSection
Section "Device"
### Available Driver options are:-
### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
### <string>: "String", <freq>: "<f> Hz/kHz/MHz"
### [arg]: arg optional
#Option "ShadowFB" # [<bool>]
#Option "DefaultRefresh" # [<bool>]
#Option "ModeSetClearScreen" # [<bool>]
Identifier "Card0"
Driver "vesa"
VendorName "ATI Technologies Inc"
BoardName "RV770 [Radeon HD 4850]"
BusID "PCI:8:0:0"
EndSection
Section "Device"
Identifier "aticonfig-Device[0]-0"
Driver "fglrx"
BusID "PCI:8:0:0"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
SubSection "Display"
Viewport 0 0
Depth 1
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 4
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 8
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 15
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 16
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection
Section "Screen"
Identifier "aticonfig-Screen[0]-0"
Device "aticonfig-Device[0]-0"
Monitor "aticonfig-Monitor[0]-0"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection
Thank you for any help.

Section "Device"
### Available Driver options are:-
### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
### <string>: "String", <freq>: "<f> Hz/kHz/MHz"
### [arg]: arg optional
#Option "ShadowFB" # [<bool>]
#Option "DefaultRefresh" # [<bool>]
#Option "ModeSetClearScreen" # [<bool>]
Identifier "Card0"
Driver "vesa"
VendorName "ATI Technologies Inc"
BoardName "RV770 [Radeon HD 4850]"
BusID "PCI:8:0:0"
EndSection
and
Section "Monitor"
Identifier "Monitor0"
VendorName "Monitor Vendor"
ModelName "Monitor Model"
EndSection
I see no reason for those to be there.
make a backup of your xorg.conf and remove / comment those lines.

Is anyone able to explain really poor performance when using 'If Exists'?

Hello all. We've recently had a performance spike when using the 'if exists' construct, which is a construct that we use through much of our code. The problem is, it appears illogical since if can be removed via a tiny modification that does
not change the core code.
I can demonstrate
This is the (simplified) format of the base original code. It's purpose is to identify when a column value has changed comparing to a main table and a complex view
select 1 from MainTable m
inner join ComplexView v on m.col2 = v.col2
where m.col3 <> v.col3
This is doing a table scan, however the table only has 17000 rows while the view only has 7000 rows. The sql executes in approximately 3 seconds.
However if we add the 'If Exists' construct around the original query, like such:
if exists (
select 1 from MainTable m
inner join ComplexView v on m.col2 = v.col2
where m.col3 <> v.col3
print 1
The sql now takes over 2 minutes to run. Note that the core sql is unchanged. All I have done is wrap it with 'If Exists'
I can't fathom why the if exists construct is taking so much longer, especially since the code code is unchanged, however more importantly I would like to understand why since we commonly use this type of syntax.
Any advice would be greatly appreciated

OK, that's interesting. Adding the top 1 clause greatly affects the performance (in a bad way).
The original query (as below) still runs in a few seconds.
select 1 from MainTable m
inner join ComplexView v on m.col2 = v.col2
where m.col3 <> v.col3
The 'Top 1' query (as below) takes almost 2 minutes however. It's exactly the same query, but with 'top 1' added to it.
select top 1 1 from MainTable m
inner join ComplexView v on m.col2 = v.col2
where m.col3 <> v.col3
I suspect that the top 1 is performing a very similar operation to the exists, in that it is 'supposed' to exit as soon as it finds a single row that satisfies it's results.
It's still not really any closer to making me understand what is causing the issue however.

Poor Performance when using Question Pooling

I'm wondering if anyone else out there is experiencing
Captivate running very slow when using question pooling. We have
about 195 questions with some using screenshots in jpeg format.
By viewing the Windows Task Manager, CP is using anywhere
between 130 to 160 K worth of memory. What is going on here? It's
hammering the system pretty hard. It takes a large effort just to
reposition the screenshot or even move a distractor.
I'm running this on a 3.20GHz machine with 3GB of RAM.
Any Captivate Gurus out there care to tackle this one?
Help.

MtnBiker1966,
I have noticed the same problem. I only have 60 slides with
43 questions and the Question Pool appears to be a big drain on
performance. Changing the buttons from Continue to Go to next slide
helped a little, but performance still drags compared to not using
a question pool. I even tried reducing the number of question
pools, but that did not affect the performance any. The search
continues.
Darin

Poor performance when using drop down box on web report

We are using dropdown box functionality in web reporting to allow easy selection of characteristics values. We have 4 dropdown boxes
that represents Region, Area, Country and division.
We need to use booked_values = 'Q' to show only relevant values for selection in the dropdown. However the issue is takes a long time for results to appear
on the template. Read from Fact table is quick but process of deriving drop down values is very slow.
<object>
         <param name="OWNER" value="SAP_BW"/>
         <param name="CMD" value="GET_ITEM"/>
         <param name="NAME" value="DROPDOWNBOX_1"/>
         <param name="ITEM_CLASS" value="CL_RSR_WWW_ITEM_FILTER_DDOWN"/>
         <param name="DATA_PROVIDER" value="DATAPROVIDER_1"/>
         <param name="BORDER_STYLE" value="BORDER"/>
         <param name="GENERATE_CAPTION" value=""/>
         <param name="IOBJNM" value="ZPC_ORG14"/>
         <param name="BOOKED_VALUES" value="Q"/>
         <param name="TARGET_DATA_PROVIDER_1" value="DATAPROVIDER_1"/>
         ITEM:            DROPDOWNBOX_1
</object>
Do you have any suggestions on how to improve performance on drop down?
Thanks, Jay

Dear Jayant Dixit,
1) If the values in the drop down box....are NOT dependent on user selection...then webserver can send them along with the first page....and cache them on client m/c...for multiple client/server dialogs....
2) If the values are changing based on what the user selected from a previous input......then...you need to do some research on how SAP Webserver could optimize the "network traffic"......For example: a) Apache webserver has a module that compresses the content on the webserver side and then send to the client...b)A Client browser plugin decompresses the received packet and displays appropriately....
3) We may need to research the latest SAP webserver capabilities....
Good luck, BB

BIBean poor performance when using Query.setSuppressRows()

Does anyone have experience in suppressing N/A cell values using BIBean? I was experimenting the use of Query.setSuppressRows(DataDirector.NA_SUPPRESSION). It does hide the rows that contains N/A values in a crosstab.
The problem is that the performance degrades significantly when I started drilling down the hierarchy. Without calling the method, I was able to drill into the pre-aggregated hierarchy in a few seconds. But with setSuppressRows(), it took almost 15 minutes to do the same drill.
Just for a comparison, I used DML to report on the same data that I wanted to drill into. With either 'zerorow' to yes or no, the data was fetched less than a second.
Thanks for any help.
- Wei

At the moment we are hoping this will be fixed in a 10g database patch which is due early 2005. However, if you are using an Analytic Workspace then you could use OLAP DML to filter the zero and NA rows before they are returned to the query. I think this involves modifying the OLAP views that return the AW objects via SQL commands.
Hope this helps
Business Intelligence Beans Product Management Team
Oracle Corporation

Poor performance when using skip-level hierarchies

Hi there,
currently we have big performance issues when drilling in a skip-level hierarchy (each drill takes around 10 seconds).
OBIEE is producing 4 physical SQL statements when drilling f.e. into the 4th level (for each level one SQL statement). The statements runs in parallel and are pretty fast (the database doesn't need more than 0,5 seconds to produce the result), but ... and here we have probably somewhere a problem ... putting all the 4 results together in OBIEE takes another 8 seconds.
This are not big datasets the database is returning - around 5-20 records for each select statement.
The question is: why does it take so long to put the data together on the server? Do we have to reconfigure some parameters to make it faster?
Please guide.
Regards,
Rafael

If you really and exclusively want to have "OBIEE can handle such queries" - i.e. not touch the database, then you had best put a clever caching strategy in place.
First angle of attack should be the database itself though. Best sit down with a data architect and/or your DBA to find the best setup possible physically and then when you've optimized that (with regard to the kind of queries emitted against it) you can move up to the OBIS. Always try t fix the issue as close to the source as possible.

Report Using Bind Variables

Hey Everyone,
I'm having a bit of trouble creating a report. I need the FROM part of the code to use bind variables. I have come up with this peice of code below but im getting the following error:
failed to parse SQL query:
ORA-06550: line 1, column 8:
PLS-00103: Encountered the symbol "" when expecting one of the following:
begin function package pragma procedure subtype type use
form
current cursor
The symbol "" was ignored.
ORA-06550: line 2, column 24:
PLS-00103: Encountered the symbol "" when expecting one of the following:
begin function package pragma procedure subtype type use
form
current
Can anyone see where im going wrong?
Thanks in advance,
-N.S.N.O.
Code*
DECLARE
x VARCHAR2 (4000);
BEGIN
x := x || 'select *';
x := x || 'from ';
x := x || :p13_schema;
x := x || '.ddl_log@';
x := x || :p13_db_name;
x := x || '_DBAAPEX.TNTEWW.COM';
RETURN (x);
END;

Hey Roel and Daylocks,
After getting frustrated for a while i deleted the page and started again. I put in the exact same code and it worked just how i wanted in the first place :S
The only thing i did different is when i was creating the report region the first time around i used a normal SQL query, For Example:
select sysdate from dual;
Then i modified it to
DECLARE
x VARCHAR2 (4000);
BEGIN
x := x || 'select ';*
x := x || 'from ';
x := x || :p14_schema;
x := x || '.ddl_log@';
x := x || :p14_db_name;
x := x || '_DBAAPEX.TNTEWW.COM';
RETURN (x);
END;
Whereas on the second attempt i used the peice of code in question straight away. Its been a bit of a frustrating morning because i used a similar peice of code for a different application, nevermind tho :)
Thanks for your replys, much appreciated.
-N.S.N.O.

Using Bind variables in SQL PLUS Report

using Bind variables in SQL PLUS Report. This report gets the arguments from the application concurrent program. Now my need is to convert the start_date and end_date to bind Variables to improve the performance. I have commented the original code in 'prompt List of Unapproved Adjustments' and used my Bind Variable but it is giving an error
error: Bind Variable "ENDING_DATE" not declared
Report Date and Time:
26-OCT-2010 15:44:13
List of Unapproved Adjustments
Bind Variable 'ENDING_DATE" not declared
Please see below the code for the sql plus report:
define p_org_id = '&1'
define p_fy_begin_date = '&2'
define p_start_date = '&3'
define p_end_date = '&4'
define p_conversion = '&5'
declare
variable begin_date date;
exec :begin_date := p_start_date;
variable ending_date date;
exec :ending_date := p_end_date;
/* Begin
:begin_date := to_date('&p_start_date','YYYY/MM/DD HH24:MI:SS');
:ending_date := to_date('&p_end_date','YYYY/MM/DD HH24:MI:SS');
End; */
set newpage none
set termout off
set pagesize 55
set linesize 180
set heading on
set feedback off
set wrap off
set space 1
set heading on
begin
dbms_application_info.set_client_info('&p_org_id');
end;
prompt
prompt Report Date and Time:
prompt ----------------------
select to_char(sysdate,'DD-MON-YYYY HH24:MI:SS')
from dual ;
prompt
prompt List of Unapproved Adjustments
prompt -------------------------------
select b.trx_number,
a.adjustment_number,
f.user_name created_by
from apps.ar_adjustments a,
apps.ra_customer_trx b,
apps.fnd_user f
where a.customer_trx_id = b.customer_trx_id
and a.status <> 'A'
and a.created_by = f.user_id
and a.creation_date between :begin_date
and :ending_date
-- and a.creation_Date between to_date('&p_start_date','YYYY/MM/DD HH24:MI:SS')
-- and to_date('&p_end_date','YYYY/MM/DD HH24:MI:SS')
order by
b.trx_number ;

Hi
Please go to customization part of the report and verify..You have set a default value out there ..And also verify your lov and look at the values ..If it is again giving you the problem ..pl delete the report and develop it again from the scratch it will be solved...
vishnu
null

Poor performance when using bind variable in report

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