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APEX Deep Linking, Authentication and Special Characters

Denes Kubicek - Wed, 2013-04-24 16:36
It seem that there is a bug in APEX regarding deep linking, authentication and parsing special characters. See this thread. In this example I am showing a simple workarround which could be also applied in other similar situations where you need to transfer information using URL.




Categories: Development

Major Formspider Pricing Update for PL/SQL Developers

Gerger Consulting - Mon, 2013-04-22 07:15
We recently ran a survey among our users and asked them what we can do better. Interestingly, the biggest pain point wasn't about the product but in the way we licensed it. Our licensing made it very difficult for developers to start small. After a few email exchanges with several users it became clear that we had to do something.We are happy to announce that we are correcting the mistake we made. Starting today, Formspider is distributed with the traditional developer seat license.This simple model makes Formspider very straightforward and affordable for the two million PL/SQL Developers.Download Formspider and start building amazing web applications, today.
Categories: Development

Token Configurations in Oracle SOA Suite PS6 ( 11.1.1.7.0)

Edwin Biemond - Sat, 2013-04-20 12:11
Oracle Soa Suite PatchSet 6 or 11.1.1.7.0  now has support for Token configurations which really can help administrators in configuring or overriding external Web Service Reference parameters like the protocol ( http, oramds or https ),  the remote host etc. And more important if you do it right you can kick out the all those Soa Suite deployment plans :-) Important to know this only works on

jQuery - my first functions

Denes Kubicek - Sat, 2013-04-20 03:58
I still remember how hard it was to make something like this working before the APEX version 4.0. You needed to create a function and then attach it to each column in your tabular form. Debugging and making changes is the next issue you had to think about. Now, using jQuery it is just a two three simple steps solution with almost no hardcoding and tricks. Also, the number of code lines you need to write is quite moderate. See this example in my demo application:

https://apex.oracle.com/pls/apex/f?p=31517:279



Categories: Development

Formspider Reference Application is now online

Gerger Consulting - Wed, 2013-04-17 02:00
You may now play the Formspider Reference Application online. The Reference Application shows the best practices in Formspider for the most common use cases developers encounter when building applications.
Categories: Development

SQL*Plus tips #4: Branching execution

XTended Oracle SQL - Tue, 2013-04-16 15:38

Today I’ll show trick how we can use branching in SQL*Plus.
Although I previously showed the conditional execution of scripts and it really can be used for branching, but today I’ll show how to do it without splitting the script into several smaller scripts. In contrast to the conditional script execution, I’ll use a different method.

It is very simple, as usual – if you want to execute only one part of script, you can just comment out all unnecessary. So depending on the conditions, we can execute a script which will start a comment.

Suppose we need to create a script, which, depending on the input parameter will be required to execute a specific query.
See how this can be done:
1. “test.sql”:

def param = &1

@if &param=1
   select 1 from dual;
/* end_if */

@if &param=2
   select 2 from dual;
/* end_if */

@if &param=3
   select 3 from dual;
/* end_if */

2. “if.sql”:

col do_next new_val do_next noprint;
select 
      case 
         when &1 then 'inc/null'
         else 'inc/comment_on'
      end as do_next
from dual;
@&do_next

3. “inc/comment_on.sql” contains only 2 chars:

/*

4. “inc/null.sql” is the same as in the previous examples – just empty file.

Ok, lets test it:

SQL> @test 1

         1
----------
         1


SQL> @test 2


         2
----------
         2


SQL> @test 3


         3
----------
         3

As you see, we got what we wanted. Please note that we have to close the multiline comments in the right places only(/* end_if */). So we cannot use in these parts another “*/”. But you can use it in another child scripts.

Same way we can make an analogue of switch/case:
“test2.sql”:

@switch &1

   @when 1 then
      select 1 from dual;
   /* end when */

   @when 2 then
      select 2 from dual;
   /* end when */

   @when 3 then
      select 3 from dual;
   /* end when */

/* end switch */

Spoiler:: switch.sql SelectShow

def switch_param=&1


Spoiler:: when.sql
SelectShow

col do_next new_val do_next noprint;
select 
      case 
         when &1 = &switch_param then 'inc/null'
         else 'inc/comment_on'
      end as do_next
from dual;
@&do_next


Example:

SQL> @test2 2

         2
----------
         2

SQL> @test2 3

         3
----------
         3

Download Formspider Reference Application

Gerger Consulting - Thu, 2013-04-11 06:28
Today we released a reference application which shows the best practices in Formspider to implement the most common use cases faced by application developers. If you want to learn Formspider or just started building your first application, we strongly recommend you to install it and take a look at its source code. You can download the scripts from the Learning Center.
Categories: Development

SQL*Plus tips #3: Iterators and recursions

XTended Oracle SQL - Tue, 2013-04-09 14:35

We all used to iterators, recursions and branching in programming, but sql*plus does not have such commands. Today I will show how to do iterators/recusions.

Suppose we want to call a script 3 times. So it would be convenient if we can do it like:

@iterate 3 @some_script

It is very easy: We can recursively call the script by reducing variable until it is greater than zero. and if a variable is zero, then call an empty “NULL” script.
iterate.sql:

-- initializing input parameters as i showed in previous tips:
@inc/input_params_init.sql;
-- for example max number of input parameters = 14:
def _INIT_PARAMS = '"&3" "&4" "&5" "&6" "&7" "&8" "&9" "&10" "&11" "&12" "&13" "&14" "&15" "&16"'
def _ITER = "&1"

prompt ------   iteration &_ITER start: "@&2  -----------;
set termout off


col _SCRIPT    new_val _SCRIPT   noprint;
col _CONTINUE  new_val _CONTINUE noprint;
col _PARAMS    new_val _PARAMS   noprint;
select 
   replace('"&3" "&4" "&5" "&6" "&7" "&8" "&9" "&10" "&11" "&12" "&13" "&14" "&15" "&16"'
          ,'${ITER}'
          ,'&_ITER'
          )          as "_PARAMS"
  ,case 
      when &1 > 0 then 'iterate '||(&1 - 1)
      else 'inc/null'
   end               as "_CONTINUE"
  ,case 
      when &1 > 0 then '&2' 
      else 'inc/null'
   end               as "_SCRIPT"
from dual;
set termout on

@&_script            &_PARAMS
@&_CONTINUE &_SCRIPT &_INIT_PARAMS

As you see i also added option to pass iteration_number as input parameter, so we can call it like: @iterate 3 script.sql ${ITER}
And null.sql in “inc” directory is just empty file.

Lets test it:

SQL> $cat test.sql
select &1 a,'&2' b,'&3' c from dual;

SQL> @iterate 3 test.sql 1 2 3
------   iteration 3 start: "@test.sql  -----------

         A B C
---------- - -
         1 2 3

------   iteration 2 start: "@test.sql  -----------

         A B C
---------- - -
         1 2 3

------   iteration 1 start: "@test.sql  -----------

         A B C
---------- - -
         1 2 3

------   iteration 0 start: "@test.sql  -----------

SQL> @iterate 2 test.sql 1 2 ${ITER}
------   iteration 2 start: "@test.sql  -----------

         A B C
---------- - -
         1 2 2

------   iteration 1 start: "@test.sql  -----------

         A B C
---------- - -
         1 2 1

------   iteration 0 start: "@test.sql  -----------

Note that last string “iteration 0 start” just means that it is last empty call. I made this only for showing how we can do postprocessing after all iterations.
Ok, it works good, but with a little modification we can also add option to call such script with list of values too:
Spoiler:: final iterate.sql SelectShow

@inc/input_params_init.sql;

set termout off
def _INIT_PARAMS = '"&3" "&4" "&5" "&6" "&7" "&8" "&9" "&10" "&11" "&12" "&13" "&14" "&15" "&16"'
col _ITER_CURR new_val _ITER_CURR noprint
col _ITER_NEXT new_val _ITER_NEXT noprint
select
   case 
      -- simple N iterations:
      when translate('&1','x0123456789','x') is null 
         then '&1'
      -- list iteration:
      when substr('&1',1,1)='(' 
         then decode( instr('&1',',')
                     ,0,substr('&1',2,length('&1')-2)
                     ,substr('&1',2,instr('&1',',')-2)
                    )
   end "_ITER_CURR",
   case 
      when translate('&1','x0123456789','x') is null 
         then 
            case 
               when '&1'>1 then 'iterate '||('&1' - 1)
               else 'inc/null'
            end
      when substr('&1',1,1)='(' 
         then 
            case 
               when instr('&1',',')=0 or '&1'='()' then 'inc/null'
               else 'iterate '
                  ||'('
                  ||decode( instr('&1',',')
                           ,0,')'
                           ,substr('&1',instr('&1',',')+1)
                          )
            end
   end "_ITER_NEXT"
from dual;

set termout on
prompt ******   iteration &_ITER_CURR start: "@&2  ***********;
set termout off

col _SCRIPT    new_val _SCRIPT   noprint;
col _PARAMS    new_val _PARAMS   noprint;
select 
   replace('"&3" "&4" "&5" "&6" "&7" "&8" "&9" "&10" "&11" "&12" "&13" "&14" "&15" "&16"'
          ,'${ITER}'
          ,'&_ITER_CURR'
          )          as "_PARAMS"
  ,case 
      when nvl('&_ITER_CURR',0) in ('0','()') then 'inc/null'
      else '&2'
   end               as "_SCRIPT"
from dual;
set termout on

@&_script             &_PARAMS
@&_ITER_NEXT &_SCRIPT &_INIT_PARAMS


See how it works:

-- iterate by list of values  (7,3,10):
SQL> @iterate (7,3,10) test.sql 1 2 ${ITER}
******   iteration 7 start: "@test.sql  ***********

         A B C
---------- - -
         1 2 7

******   iteration 3 start: "@test.sql  ***********

         A B C
---------- - -
         1 2 3

******   iteration 10 start: "@test.sql  ***********

         A B C
---------- - --
         1 2 10

-- now with simple 2 iterations:
SQL> @iterate 2 test.sql 1 2 ${ITER}
******   iteration 2 start: "@test.sql  ***********

         A B C
---------- - -
         1 2 2

******   iteration 1 start: "@test.sql  ***********

         A B C
---------- - -
         1 2 1

So if you call script with “iterate N …” it will iterate N times, and if you specify “iterate (X,Y,…,Z)” it will iterate by this list.

PS. About a branching i will wrote later…

Formspider in Brazil

Gerger Consulting - Tue, 2013-04-09 05:49
Brazil is known for its great soccer players and Formspider developers. Here is one of them. Meet Ricardo Monteiro...
Categories: Development

SQL*Plus tips. #2

XTended Oracle SQL - Mon, 2013-04-01 17:33

I think you know the famous print_table procedure by Tom Kyte. It is really great, but a little hard(it requires create procedure or place it in anonymous block) and in last oracle versions we can do same with one simple query with xmltable/xmlsequence:

SQL> select *
  2  from
  3     xmltable( '/ROWSET/ROW/*'
  4               passing xmltype(cursor(select * from hr.employees where rownum<3))
  5               columns
  6                  col varchar2(100) path 'name()'
  7                 ,val varchar2(100) path '.'
  8        );

COL                            VAL
------------------------------ ------------------------------------------------------
EMPLOYEE_ID                    198
FIRST_NAME                     Donald
LAST_NAME                      OConnell
EMAIL                          DOCONNEL
PHONE_NUMBER                   650.507.9833
HIRE_DATE                      21-JUN-07
JOB_ID                         SH_CLERK
SALARY                         2600
MANAGER_ID                     124
DEPARTMENT_ID                  50
EMPLOYEE_ID                    199
FIRST_NAME                     Douglas
LAST_NAME                      Grant
EMAIL                          DGRANT
PHONE_NUMBER                   650.507.9844
HIRE_DATE                      13-JAN-08
JOB_ID                         SH_CLERK
SALARY                         2600
MANAGER_ID                     124
DEPARTMENT_ID                  50

20 rows selected.

It is very easy, but for conveniency we need to add “rownum”:

SQL> select *
  2  from
  3     xmltable( 'for $a at $i in /ROWSET/ROW
  4                   ,$r in $a/*
  5                     return element ROW{
  6                                       element ROW_NUM{$i}
  7                                      ,element COL_NAME{$r/name()}
  8                                      ,element COL_VALUE{$r/text()}
  9                                      }'
 10               passing xmltype(cursor(select * from hr.employees where rownum<3))
 11               columns
 12                  row_num   int
 13                 ,col_name  varchar2(30)
 14                 ,col_value varchar2(100)
 15        );

   ROW_NUM COL_NAME                       COL_VALUE
---------- ------------------------------ ------------------------------------------
         1 EMPLOYEE_ID                    198
         1 FIRST_NAME                     Donald
         1 LAST_NAME                      OConnell
         1 EMAIL                          DOCONNEL
         1 PHONE_NUMBER                   650.507.9833
         1 HIRE_DATE                      21-JUN-07
         1 JOB_ID                         SH_CLERK
         1 SALARY                         2600
         1 MANAGER_ID                     124
         1 DEPARTMENT_ID                  50
         2 EMPLOYEE_ID                    199
         2 FIRST_NAME                     Douglas
         2 LAST_NAME                      Grant
         2 EMAIL                          DGRANT
         2 PHONE_NUMBER                   650.507.9844
         2 HIRE_DATE                      13-JAN-08
         2 JOB_ID                         SH_CLERK
         2 SALARY                         2600
         2 MANAGER_ID                     124
         2 DEPARTMENT_ID                  50

20 rows selected.

Now we can create simple script for it with formatting:
Spoiler:: print_table.sql SelectShow

-- show output  
set termout on
-- but without echo
set echo off
-- without newpage on start:
set embedded on
-- scrolling control
set pause on
-- two lines between rows:
set newpage 2
-- text for prompt after each page:
set pause "Press Enter to view next row..."
-- new page on new "row_num"
break on row_num skip page

-- main query:
select *
from 
   xmltable( 'for $a at $i in /ROWSET/ROW
                 ,$r in $a/*
                   return element ROW{
                                     element ROW_NUM{$i}
                                    ,element COL_NAME{$r/name()}
                                    ,element COL_VALUE{$r/text()}
                                    }'
             passing xmltype(cursor( &1 ))
             columns
                row_num   int
               ,col_name  varchar2(30) 
               ,col_value varchar2(100) 
      );
-- disabling pause and breaks:
set pause off
clear breaks


Usage example:
print_table example
As you see script works fine, but it is require to pass query as parameter, though sometimes it is not so convenient. For example if we want started query and later decided to show it with print_table. In that case we can create scripts with tricks from previous part:
Spoiler:: print_last.sql SelectShow

store set settings.sql replace
-- saving previous query:
save tmp.sql replace

-- OS-dependent removing trailing slash from file, choose one:
-- 1. for *nix through head:
!head -1 tmp.sql >tmp2.sql

-- 2. for for *nix through grep:
--!grep -v tmp.sql >tmp2.sql

-- 3. for windows without grep and head:
-- $cmd /C findstr /v /C:"/" tmp.sql > tmp2.sql

-- 4. for windows with "head"(eg from cygwin)
--$cmd /C head -1 tmp.sql > tmp2.sql

-- 5. for windows with "grep":
--$cmd /C grep -v "/" tmp.sql > tmp2.sql



-- same setting as in print_table:
set termout on echo off embedded on pause on newpage 2
set pause "Press Enter to view next row..."
break on row_num skip page

-- main query:
select *
from
   xmltable( 'for $a at $i in /ROWSET/ROW
                 ,$r in $a/*
                   return element ROW{
                                     element ROW_NUM{$i}
                                    ,element COL_NAME{$r/name()}
                                    ,element COL_VALUE{$r/text()}
                                    }'
             passing dbms_xmlgen.getxmltype(
             q'[
               @tmp2.sql
             ]'
             )
             columns
                row_num   int
               ,col_name  varchar2(30)
               ,col_value varchar2(100)
      );
-- disabling pause and breaks:
set pause off
clear breaks
@settings.sql


Example: Spoiler:
SelectShow

SQL> select * from hr.employees where rownum<3;

EMPLOYEE_ID FIRST_NAME           LAST_NAME                 EMAIL                     PHONE_NUMBER      HIRE_DATE JOB_ID    SALARY COMMISSION_PCT MANAGER_ID DEPARTMENT_ID
----------- -------------------- ------------------------- ------------------------- -------------------- --------- ---------- ---------- -------------- ---------- -------------
        198 Donald               OConnell                  DOCONNEL                  650.507.9833         21-JUN-07 SH_CLERK         2600                       124            50
        199 Douglas              Grant                     DGRANT                    650.507.9844         13-JAN-08 SH_CLERK         2600                       124            50

Elapsed: 00:00:00.01
SQL> @print_last
Wrote file settings.sql
Wrote file tmp.sql

   ROW_NUM COL_NAME                       COL_VALUE
---------- ------------------------------ ----------------------------------------------------------------------------------------------------
         1 EMPLOYEE_ID                    198
           FIRST_NAME                     Donald
           LAST_NAME                      OConnell
           EMAIL                          DOCONNEL
           PHONE_NUMBER                   650.507.9833
           HIRE_DATE                      21-JUN-07
           JOB_ID                         SH_CLERK
           SALARY                         2600
           MANAGER_ID                     124
           DEPARTMENT_ID                  50
Press Enter to view next row...


PS. if you will use xmltype(cursor(…)) on versions less that 11.2.0.3 you can get errors with xml rewriting. In this case you need to disable it:

alter session set events '19027 trace name context forever, level 0x1';
Update:
Vladimir Przyjalkowski rightly pointed out that such approach will be suboptimal in case of big amount of data:

A nice toy, but i’m sure it will not tolerate big data.

It is absolutely true, because at first, “xmltype(cursor(…))” aggregated data as xmltype, and only then xmltable returns data.
But I use print_table for small amount of data only, and in case of when i want to see sample of data, i usually add limitation by rownum, which also convenient because it automatically changes optimizer mode with enabled parameter “_optimizer_rownum_pred_based_fkr” (it is default):

SQL> @param_ rownum

NAME                               VALUE   DEFLT  TYPE     DESCRIPTION
---------------------------------- ------- ------ -------- ------------------------------------------------------
_optimizer_rownum_bind_default     10      TRUE   number   Default value to use for rownum bind
_optimizer_rownum_pred_based_fkr   TRUE    TRUE   boolean  enable the use of first K rows due to rownum predicate
_px_rownum_pd                      TRUE    TRUE   boolean  turn off/on parallel rownum pushdown optimization

However, we can easily change the our query to make it optimally with a lot of data too:

select row_num
      ,t2.*
from 
   (select rownum row_num
         , column_value x
    from table(xmlsequence(cursor( &1 )))
   ) t1
  ,xmltable( '/ROW/*'
             passing t1.x
             columns
                col_num for ordinality
               ,col_name  varchar2(30) path 'name()'
               ,col_value varchar2(100) path '.'
      )(+) t2;

Lets test it with pipelined function which will pipe rows infinitely and log count of fetched rows:

-- drop table xt_log purge;
-- drop function f_infinite;

create table xt_log(n int);

create function f_infinite 
   return sys.ku$_objnumset pipelined 
as
   i int:=0;
   pragma autonomous_transaction;
begin
   loop 
      i:=i+1;
      insert into xt_log values(i);
      commit;
      pipe row(i);
   end loop;

exception 
   when NO_DATA_NEEDED then
      commit;
end;
/

Spoiler:: New version of print_table: print_table2.sql SelectShow

-- set arraysize for minimal value, so sqlplus did not fetch extra rows:
set arraysize 2
-- show output  
set termout on
-- but without echo
set echo off
-- without newpage on start:
set embedded on
-- scrolling control
set pause on
-- two lines between rows:
set newpage 2
-- text for prompt after each page:
set pause "Press Enter to view next row..."
-- new page on new "row_num"
break on row_num skip page

-- main query:
select row_num
      ,t2.*
from 
   (select rownum row_num
         , column_value x
    from table(xmlsequence(cursor( &1 )))
   ) t1
  ,xmltable( '/ROW/*'
             passing t1.x
             columns
                col_num for ordinality
               ,col_name  varchar2(30) path 'name()'
               ,col_value varchar2(100) path '.'
      )(+) t2;
-- disabling pause and breaks:
set pause off
clear breaks


And look final test:

SQL> select * from xt_log;

no rows selected

SQL> @print_table2 "select * from table(f_infinite)"
Press Enter to view next row...


   ROW_NUM    COL_NUM COL_NAME                       COL_VALUE
---------- ---------- ------------------------------ -----------
         1          1 COLUMN_VALUE                   1
Press Enter to view next row...


   ROW_NUM    COL_NUM COL_NAME                       COL_VALUE
---------- ---------- ------------------------------ -----------
         2          1 COLUMN_VALUE                   2
Press Enter to view next row...


   ROW_NUM    COL_NUM COL_NAME                       COL_VALUE
---------- ---------- ------------------------------ -----------
         3          1 COLUMN_VALUE                   3
Press Enter to view next row...


   ROW_NUM    COL_NUM COL_NAME                       COL_VALUE
---------- ---------- ------------------------------ -----------
         4          1 COLUMN_VALUE                   4
Press Enter to view next row...

   ROW_NUM    COL_NUM COL_NAME                       COL_VALUE
         5          1 COLUMN_VALUE                   5
Press Enter to view next row...


6 rows selected.
-------------------------------
SQL> select * from xt_log;

         N
----------
         1
         2
         3
         4
         5
         6
         7

7 rows selected.

So we got what we wanted!

PS. Full scripts:
1. Simple:
print_table.sql
2. For big queries: print_table2.sql

Categories: Development

Working with the Sunburst ADF Component

Shay Shmeltzer - Mon, 2013-04-01 14:49

JDeveloper 11.1.1.7 just hit the streets and among the new features it contains are several new data visualization ADF Faces components including timeline, treemap, and sunburst.

I got to play with the sunburst component a while back while building some internal demos - so I thought I'll provide a quick overview of some of the things you can do with it, and how to work with it at design time.

The sunburst component is used to visually show numerical data along one or two axises relating to something. One axis of data will show as the size of slices and the other data will show as a color. You can think about it as a two axis pie chart. The sunburst also allow for drilling into detail levels.

In the below example I'm showing just one set of data that has to do with the total orders broken in several levels - region->country->customer.

So here is the demo:

For those interested in the actual JSF code it is below:

          <dvt:sunburst id="s1" value="#{bindings.RegionSales1.treeModel}"
                        var="row" animationOnDataChange="alphaFade"
                        animationOnDisplay="fan" displayLevelsChildren="0"
                        styleClass="AFStretchWidth"
                        inlineStyle="height:620.0px;" legendSource="ag1"
                        colorLabel="Sales">
            <af:switcher facetName="#{row.hierTypeBinding.name}" id="s2">
              <f:facet name="RegionSales10">
                <dvt:sunburstNode value="#{row.Total}" label="#{row.Name}"
                                  id="sn3" drilling="insert">
                  <dvt:attributeGroups id="ag1" value="#{row.Total}"
                                       label="#{row.Total}" type="color"
                                       attributeType="continuous" minValue="0"
                                       maxValue="3000000" minLabel="0"
                                       maxLabel="3M">
                    <f:attribute name="color1" value="11AA55"/>
                    <f:attribute name="color2" value="44BB77"/>
                    <f:attribute name="color3" value="77DD99"/>
                  </dvt:attributeGroups>
                </dvt:sunburstNode>
              </f:facet>
              <f:facet name="RegionSales11">
                <dvt:sunburstNode value="#{row.Total}" label="#{row.Country}"
                                  id="sn1" drilling="insert">
                  <dvt:attributeGroups id="ag2" value="#{row.Total}"
                                       label="#{row.Total}" type="color"
                                       attributeType="continuous" minValue="0"
                                       maxValue="2800000" minLabel="0"
                                       maxLabel="2.8M">
                    <f:attribute name="color1" value="11AA55"/>
                    <f:attribute name="color2" value="44BB77"/>
                    <f:attribute name="color3" value="77DD99"/>
                  </dvt:attributeGroups>
                </dvt:sunburstNode>
              </f:facet>
              <f:facet name="RegionSales12">
                <dvt:sunburstNode value="#{row.Total}" label="#{row.Name1}"
                                  id="sn2" drilling="insertAndReplace"/>
              </f:facet>
            </af:switcher>
          </dvt:sunburst>



Categories: Development

Testing Activiti BPM on WebLogic 12c

Edwin Biemond - Fri, 2013-03-29 14:33
Activiti is a great open source workflow + BPM platform, which you can use in your own java application (embedded) or test it in the provided Rest or Web demo applications. Activiti also provides  an Eclipse designer plugin which you can use to create your own BPMN 2.0 definitions and export this to the Activiti applications. In blogpost I will show you the steps how to get this working on the

SQL*Plus tips. #1

XTended Oracle SQL - Thu, 2013-03-28 17:58

If you are using SQL*Plus, you are likely to use the input parameters. And if you omit one of them, SQL*Plus will show prompt for it, like this:

SQL> get test.sql
  1  select 'Input variable 1 = &1' from dual
  2  union all
  3  select 'Input variable 2 = &2' from dual
  4  union all
  5* select 'Input variable 3 = &3' from dual
SQL> @test var1 var2
Enter value for 3:

'INPUTVARIABLE1=VAR1'
-----------------------
Input variable 1 = var1
Input variable 2 = var2
Input variable 3 =

Elapsed: 00:00:00.01

It is allright, if all variables are needed, but what if we don’t want to press enter for all omitted variables or specify they(especially if script can be start in silent, non interactive mode) and want to use default values for omitted variables or these variables can be unnecessary?
Strictly speaking, there are many different techniques for solving it, see some of them:
Spoiler:: Comma-separated params SelectShow

SQL> get test1
  1  col var1 new_value var1 noprint
  2  col var2 new_value var2 noprint
  3  col var3 new_value var3 noprint
  4  set termout off
  5  with any_splitting_technique as (
  6       select *
  7       from xmltable('ora:tokenize(.,",")[position()>1]'
  8                      passing ','||'&1'
  9                      columns
 10                        i for ordinality
 11                       ,"." varchar2(30)
 12                    )
 13  )
 14  select
 15    nvl("1",'default1') var1
 16   ,nvl("2",'default2') var2
 17   ,nvl("3",'default3') var3
 18  from any_splitting_technique
 19  pivot (max(".") for i in (1,2,3))
 20  /
 21  set termout on
 22* prompt var1 = &var1, var2 = &var2, var3 = &var3;
SQL> @test1 1,2,3
var1 = 1, var2 = 2, var3 = 3
SQL> @test1 1,2
var1 = 1, var2 = 2, var3 = default3


Spoiler:: With SPOOL and DEFINE
SelectShow

SQL> get test2
  1  set termout off
  2  spool tmp.sql
  3  def 1
  4  def 2
  5  def 3
  6  spool off
  7  col var1 new_value var1
  8  col var2 new_value var2
  9  col var3 new_value var3
 10  with tmp as (
 11  select '
 12  @tmp.sql
 13  ' params from dual
 14  )
 15  select
 16    nvl(regexp_substr(params,'DEFINE 1\s+ = "([^"]*)',1,1,'i',1),'default1') var1
 17  , nvl(regexp_substr(params,'DEFINE 2\s+ = "([^"]*)',1,1,'i',1),'default2') var2
 18  , nvl(regexp_substr(params,'DEFINE 3\s+ = "([^"]*)',1,1,'i',1),'default3') var3
 19  from tmp
 20  ;
 21  col var1 clear;
 22  col var2 clear;
 23  col var3 clear;
 24  set termout on
 25  prompt var1 = &var1, var2 = &var2, var3 = &var3;
 26  undef 1
 27  undef 2
 28* undef 3
 29  .
SQL> @test2 1 2 3
var1 = 1, var2 = 2, var3 = 3
SQL> @test2 1 2
var1 = 1, var2 = 2, var3 = default3


Last example also shows a very useful way to read file into a variable.
But i think, the best option for initializing parameters is the
solution by Vladimir Begun:

SQL> get test3
  1  set termout off
  2  COLUMN 1 NEW_VALUE 1    noprint
  3  COLUMN 2 NEW_VALUE 2    noprint
  4  COLUMN 3 NEW_VALUE 3    noprint
  5  SELECT '' "1", '' "2", '' "3" FROM dual WHERE 1=0;
  6  SELECT nvl('&1','default1') "1"
  7       , nvl('&2','default2') "2"
  8       , nvl('&3','default3') "3"
  9    FROM dual;
 10  col var1 clear;
 11  col var2 clear;
 12  col var3 clear;
 13  set termout on
 14  prompt var1 = &1, var2 = &2, var3 = &3;
 15  undef 1
 16  undef 2
 17* undef 3
 18  .
SQL> @test3 1 2 3
var1 = 1, var2 = 2, var3 = 3
SQL> @test3 1 2
var1 = 1, var2 = 2, var3 = default3

So i can create 2 include files – for execution at the start and at the end of all scripts. I created directory “inc” for include files and files:
Spoiler:: inc/s_begin.sql SelectShow

store set splus_restore.sql replace
set termout off
COLUMN  1  NEW_VALUE  1    noprint
COLUMN  2  NEW_VALUE  2    noprint
COLUMN  4  NEW_VALUE  4    noprint
COLUMN  3  NEW_VALUE  3    noprint
COLUMN  5  NEW_VALUE  5    noprint
COLUMN  6  NEW_VALUE  6    noprint
COLUMN  7  NEW_VALUE  7    noprint
COLUMN  8  NEW_VALUE  8    noprint
COLUMN  9  NEW_VALUE  9    noprint
COLUMN 10  NEW_VALUE 10    noprint
COLUMN 11  NEW_VALUE 11    noprint
COLUMN 12  NEW_VALUE 12    noprint
COLUMN 13  NEW_VALUE 13    noprint
COLUMN 14  NEW_VALUE 14    noprint
COLUMN 15  NEW_VALUE 15    noprint
COLUMN 16  NEW_VALUE 16    noprint


SELECT ''  "1", '' "5", ''  "9", '' "13"
      ,''  "2", '' "6", '' "10", '' "14"
      ,''  "3", '' "7", '' "11", '' "15"
      ,''  "4", '' "8", '' "12", '' "16"
  FROM dual
 WHERE 1=0;
set termout on;


and Spoiler:: inc/s_end.sql
SelectShow

undef 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
@splus_restore;

And for example get_index.sql: Spoiler:: get_index.sql SelectShow

@inc/s_begin;
col table_owner format a12
col column_name format a30
col index_owner format a12
col index_name  format a30

col "#" format 99
break on table_owner on table_name on index_owner on index_name on partition_name on mbytes on bytes on blocks
select 
         ic.table_owner
        ,ic.table_name
        ,ic.index_owner
        ,ic.index_name
        ,s.partition_name
        ,round(s.bytes/1024/1024) mbytes
        ,s.blocks
        ,ic.column_position "#"
        ,decode(ic.column_position,1,'','  ,')||ic.column_name column_name
from dba_ind_columns ic 
    ,dba_segments s
where
     upper(ic.table_name) like upper('&1')
 and upper(ic.table_owner) like nvl(upper('&2'),'%')
 and s.owner        = ic.index_owner
 and s.segment_name = ic.index_name
order by
         1,2,3,4,8
/
clear break;
col "#" clear;
@inc/s_end;

Spoiler:: Sample output SelectShow

SQL> @get_indexes wrh$%tab%stat xtender
Wrote file splus_restore.sql

no rows selected

Elapsed: 00:00:05.79
SQL> @get_indexes wrh$%undostat
Wrote file splus_restore.sql

TABLE_OWNER  TABLE_NAME     INDEX_OWNER  INDEX_NAME        PARTITION_NAME  MBYTES  BLOCKS   # COLUMN_NAME
------------ -------------- ------------ ----------------- -------------- ------- ------- --- --------------------
SYS          WRH$_UNDOSTAT  SYS          WRH$_UNDOSTAT_PK                       0      16   1 BEGIN_TIME
                                                                                            2   ,END_TIME
                                                                                            3   ,DBID
                                                                                            4   ,INSTANCE_NUMBER

As you see i can omit owner parameter and in this case it will search in all schemas.

Maliakos-Kleidi Construction Uses Formspider

Gerger Consulting - Tue, 2013-03-19 06:31
Maliakos-Kleidi Construction Company uses an application built with Formspider to manage the design documents used during the construction of the Temp Tunnel in Greece. http://goo.gl/VSP0ZContinue reading the story on the Formspider web site.
Categories: Development

Select List with Dynamic LOV and ORA-06502: PL/SQL: numeric or value error: character string buffer too small

Denes Kubicek - Tue, 2013-03-19 01:45
If you need to create a dynamic SQL for a select list or any other type of a LOV, your query should not exceed 4000 characters. In case it does, you will get the "ORA-06502: PL/SQL: numeric or value error: character string buffer too small" error. That is the internal limitation of the APEX table storing the item attribute information. In case you can't rewrite your SQL to satisfy this limitation, you may use the package I created for that purpose. It is quite simple and it does the following:

1. It will use the apex_collection package to parse the query and crate a collection

2. It will query the collection and use a pipelined function to return a simple LOV (SELECT d, r FROM table)

You can also use the get_long_dynamic_query function in the package to generate your dynamic SQL. The example at apex.oracle.com I provided extends the query with "dummy" conditions in order to make it long enough and prove the concept.



Categories: Development

Example of controlling “direct path reads” decision through SQL profile hints (index_stats/table_stats)

XTended Oracle SQL - Sun, 2013-03-17 17:33

Previously i showed not obvious example with hint INDEX_STATS(“OWNER”.”TABLE_NAME”, “INDEX_NAME”, scale, blocks=X, rows=Y). Strictly speaking i don’t know how exactly cbo calculates number of index leaf blocks in that case: in those examples they was 1981 for “blocks=1, rows=50″ and 49525 for “blocks=5, rows=10″.
But i know that with “INDEX_STATS(“OWNER”.”TABLE_NAME”, “INDEX_NAME”, scale, blocks=X)” i can set exact blocks number.
Also those test-cases didn’t show when occurs decision changing. So todays my test will show it.

BTW, it is very interesting that a turning point was _very_large_object_threshold, but not 5 * _small_table_threshold. AFAIK, direct path reads decision depends on many factors (such as number of object blocks in buffer cache), and would be great to know all of them.
You can download script as file: controlling_direct_reads_with_profiles.sql
Spoiler:: Test code SelectShow

/** SQLPLUS Example of controlling adaptive serial direct path reads through SQL profiles.
*/
set serverout on termout on timing off feed off;
clear scr;
def _IF_XT_RUNSTATS_EXISTS="--"
col if_xt_runstats_exists new_value _IF_XT_RUNSTATS_EXISTS noprint;
select decode(count(*),1,'  ','--') if_xt_runstats_exists 
from all_objects where object_name='XT_RUNSTATS' and rownum=1;
/**
 * Main test.
 * You can use it also in other clients, 
 * but in that case you have to manually 
 * set substitution variable _IF_XT_RUNSTATS_EXISTS:
 *  if you have not this package - to "--" 
 *  otherwise                    - to space(" ")
 * Latest version of XT_RUNSTATS you can get from:
 *  https://github.com/xtender/xt_runstats
 */

declare

   C_SQL_TEXT      constant varchar2(300):='SELECT SUM(A) FROM XT_IFFS T';
   C_PROFILE_NAME  constant varchar2(30) :='PRF_ADPR_TEST';
   v_small_table_threshold        int;
   v_db_block_buffers             int;
   v_very_large_object_threshold  int;
   v__db_cache_size               int;
      
   procedure exec(p varchar2) is
     e_table_is_not_created_yet exception;
     e_index_is_not_created_yet exception;
     pragma exception_init(e_table_is_not_created_yet, -942);
     pragma exception_init(e_index_is_not_created_yet, -1418);
   begin
     execute immediate p;
   exception 
      when e_table_is_not_created_yet 
        or e_index_is_not_created_yet
        then null;
   end;

   /** Creating table and setting stats */   
   procedure create_table is
   begin
     exec('drop table xt_iffs purge');
     exec('create table xt_iffs as 
           with gen as(
                       select level a,mod(level,10) b,lpad(1,50,1) c
                       from dual 
                       connect by level<=1e3
           )
           select gen.* 
           from gen,gen gen2'
         );
     --dbms_stats.set_table_stats('','XT_IFFS',numrows => 1e6,numblks => 5e5,avgrlen => 800);
     dbms_stats.gather_table_stats('','XT_IFFS');
   end;
   
   /** Recreating index and setting stats */
   procedure create_index is
   begin
     exec('drop index ix_iffs');
     exec('create index ix_iffs on xt_iffs(a,b)');
     dbms_stats.set_index_stats('','IX_IFFS',numrows => 1e6,numlblks => 1e4);
   end;
   
   /** Setting index numblks for query through SQL profile */
   procedure set_numblks(p_numblks int) is
     e_profile_not_created_yet  exception;
     pragma exception_init( e_profile_not_created_yet, -13833);
   begin
     begin
        dbms_sqltune.drop_sql_profile(C_PROFILE_NAME);
     exception when e_profile_not_created_yet then null;
     end;
     dbms_sqltune.import_sql_profile(
        sql_text    => C_SQL_TEXT,
        profile     => sys.sqlprof_attr(
                                 'INDEX_FFS(@"SEL$1" "T"@"SEL$1" ("XT_IFFS"."A"))'
                                ,'INDEX_STATS("'||user||'"."XT_IFFS", "IX_IFFS", scale, blocks='||p_numblks||')'
                       ),
        category     => 'DEFAULT',
        name        => C_PROFILE_NAME,
        force_match => false,
        replace     => true
     );
   end; 
     
   procedure test( p_description varchar2
                 , p_numblks int default null) is

     type t_seg_stat is 
        table of number 
        index by v$segstat_name.name%type;
     -- segments statistics by index:
     cursor c_stats is
        select sn.name,nvl(st.value,0) value
        from v$segstat_name sn
            ,v$segment_statistics st 
        where 
              sn.statistic#     = st.statistic#(+)
          and st.owner(+)       = user 
          and st.object_name(+) ='IX_IFFS';
     -- var for previous stats:
     v_pre     t_seg_stat;
     v_delta   number;
     n         number;
   begin
     dbms_output.put_line('-');
     dbms_output.put_line('-');
     dbms_output.put_line(lpad('-',150,'-'));
     dbms_output.put_line(lpad('-',150,'-'));
     dbms_output.put_line(  '###                ' 
                         || p_description||': '
                         ||nvl(to_char(p_numblks),'default')||' blocks');
     dbms_output.put_line('-');

     create_index;
     -- if p_numblks is null then default stats used
     if p_numblks is not null then
       set_numblks(p_numblks);
     end if;
     execute immediate C_SQL_TEXT into n;
     exec('alter system flush buffer_cache');
     -- saving segment statistics
     for r in c_stats loop
        v_pre(r.name) := r.value;
     end loop;

     &_IF_XT_RUNSTATS_EXISTS  xt_runstats.init(p_latches => false);
     -- executing query
     execute immediate C_SQL_TEXT into n;
   &_IF_XT_RUNSTATS_EXISTS  xt_runstats.snap;
   &_IF_XT_RUNSTATS_EXISTS  xt_runstats.print(
   &_IF_XT_RUNSTATS_EXISTS     p_stats_mask => '(reads (cache|direct)\.)|index fast full scans \((full|direct)'
   &_IF_XT_RUNSTATS_EXISTS    ,p_sta_diff_pct => 0);

     -- printing segments stats delta:
     for r in c_stats loop
        v_delta:= r.value - v_pre(r.name);
        if v_delta!=0 then
          dbms_output.put_line( rpad(r.name,40,'.')||v_delta );
        end if;
     end loop;
   end;

   procedure load_and_print_params is
   begin
      select
         max(decode(a.ksppinm, '_small_table_threshold'       ,b.ksppstvl)) 
        ,max(decode(a.ksppinm, '_db_block_buffers'            ,b.ksppstvl))
        ,max(decode(a.ksppinm, '_very_large_object_threshold' ,b.ksppstvl))
        ,max(decode(a.ksppinm, '__db_cache_size'              ,b.ksppstvl))
         into v_small_table_threshold,v_db_block_buffers,v_very_large_object_threshold,v__db_cache_size
      from
        sys.x$ksppi a
       ,sys.x$ksppcv b
      where
           a.indx = b.indx
       and a.ksppinm in('_small_table_threshold','_db_block_buffers','_very_large_object_threshold','__db_cache_size');
      dbms_output.put_line('_small_table_threshold       = '||v_small_table_threshold);
      dbms_output.put_line('_db_block_buffers            = '||v_db_block_buffers);
      dbms_output.put_line('_very_large_object_threshold = '||v_very_large_object_threshold);
      dbms_output.put_line('__db_cache_size              = '||v__db_cache_size);
      
   end;
begin
  create_table;
  load_and_print_params;

  test( '_very_large_object_threshold + 1'
       ,v_db_block_buffers * v_very_large_object_threshold/100 + 1 );
  test( '_very_large_object_threshold'
       ,v_db_block_buffers * v_very_large_object_threshold/100     );
  test( '_very_large_object_threshold - 1'
       ,v_db_block_buffers * v_very_large_object_threshold/100 - 1 );

  test( '_db_block_buffers + 1'
       ,v_db_block_buffers + 1 );
  test( '_db_block_buffers - 1'
       ,v_db_block_buffers - 1 );
  
  test( '_small_table_threshold * 5 + 1'
       ,v_small_table_threshold * 5 + 1 );
  test( '_small_table_threshold * 5 - 1'
       ,v_small_table_threshold * 5 - 1 );

  test( ' 1 block ', 1);
  test( ' Default ', null);

  test( ' Again _very_large_object_threshold + 1'
       ,v_db_block_buffers * v_very_large_object_threshold/100 + 1 );
  test( ' Again _very_large_object_threshold'
       ,v_db_block_buffers * v_very_large_object_threshold/100     );

end;
/


Spoiler:: Test results
SelectShow

_small_table_threshold       = 166
_db_block_buffers            = 8347
_very_large_object_threshold = 500
__db_cache_size              = 4194304
-
-
------------------------------------------------------------------------------
------------------------------------------------------------------------------
###                _very_large_object_threshold + 1: 41736 blocks
-
################     Results:      ##################
Run #  01 ran in 11 hsecs
##########################################################
Statistics                               | Run # 1
##########################################################
physical reads cache.................... |              1
physical reads direct................... |          2,491
index fast full scans (full)............ |              1
index fast full scans (direct read)..... |              1
##########################################################
-
logical reads...........................2496
physical reads..........................2492
physical read requests..................86
physical reads direct...................2491
segment scans...........................1
-
-
------------------------------------------------------------------------------
------------------------------------------------------------------------------
###                _very_large_object_threshold: 41735 blocks
-
################     Results:      ##################
Run #  01 ran in 6 hsecs
##########################################################
Statistics                               | Run # 1
##########################################################
physical reads cache.................... |          2,494
physical reads direct................... |              0
index fast full scans (full)............ |              1
index fast full scans (direct read)..... |              0
##########################################################
-
logical reads...........................2496
physical reads..........................2494
physical read requests..................95
segment scans...........................1
-
-
------------------------------------------------------------------------------
------------------------------------------------------------------------------
###                _very_large_object_threshold - 1: 41734 blocks
-
################     Results:      ##################
Run #  01 ran in 11 hsecs
##########################################################
Statistics                               | Run # 1
##########################################################
physical reads cache.................... |          3,386
physical reads direct................... |              1
index fast full scans (full)............ |              1
index fast full scans (direct read)..... |              0
##########################################################
-
logical reads...........................2512
physical reads..........................2494
physical read requests..................95
segment scans...........................1
-
-
------------------------------------------------------------------------------
------------------------------------------------------------------------------
###                _db_block_buffers + 1: 8348 blocks
-
################     Results:      ##################
Run #  01 ran in 6 hsecs
##########################################################
Statistics                               | Run # 1
##########################################################
physical reads cache.................... |          2,494
physical reads direct................... |              0
index fast full scans (full)............ |              1
index fast full scans (direct read)..... |              0
##########################################################
-
logical reads...........................2512
physical reads..........................2494
physical read requests..................95
segment scans...........................1
-
-
------------------------------------------------------------------------------
------------------------------------------------------------------------------
###                _db_block_buffers - 1: 8346 blocks
-
################     Results:      ##################
Run #  01 ran in 8 hsecs
##########################################################
Statistics                               | Run # 1
##########################################################
physical reads cache.................... |          2,494
physical reads direct................... |              0
index fast full scans (full)............ |              1
index fast full scans (direct read)..... |              0
##########################################################
-
logical reads...........................2512
physical reads..........................2494
physical read requests..................95
segment scans...........................1
-
-
------------------------------------------------------------------------------
------------------------------------------------------------------------------
###                _small_table_threshold * 5 + 1: 831 blocks
-
################     Results:      ##################
Run #  01 ran in 6 hsecs
##########################################################
Statistics                               | Run # 1
##########################################################
physical reads cache.................... |          2,494
physical reads direct................... |              0
index fast full scans (full)............ |              1
index fast full scans (direct read)..... |              0
##########################################################
-
logical reads...........................2512
physical reads..........................2494
physical read requests..................95
segment scans...........................1
-
-
------------------------------------------------------------------------------
------------------------------------------------------------------------------
###                _small_table_threshold * 5 - 1: 829 blocks
-
################     Results:      ##################
Run #  01 ran in 7 hsecs
##########################################################
Statistics                               | Run # 1
##########################################################
physical reads cache.................... |          2,494
physical reads direct................... |              0
index fast full scans (full)............ |              1
index fast full scans (direct read)..... |              0
##########################################################
-
logical reads...........................2496
physical reads..........................2494
physical read requests..................95
segment scans...........................1
-
-
------------------------------------------------------------------------------
------------------------------------------------------------------------------
###                 1 block : 1 blocks
-
################     Results:      ##################
Run #  01 ran in 6 hsecs
##########################################################
Statistics                               | Run # 1
##########################################################
physical reads cache.................... |          2,494
physical reads direct................... |              0
index fast full scans (full)............ |              1
index fast full scans (direct read)..... |              0
##########################################################
-
logical reads...........................2512
physical reads..........................2494
physical read requests..................95
segment scans...........................1
-
-
------------------------------------------------------------------------------
------------------------------------------------------------------------------
###                 Default : default blocks
-
################     Results:      ##################
Run #  01 ran in 7 hsecs
##########################################################
Statistics                               | Run # 1
##########################################################
physical reads cache.................... |          2,494
physical reads direct................... |              0
index fast full scans (full)............ |              1
index fast full scans (direct read)..... |              0
##########################################################
-
logical reads...........................2496
physical reads..........................2494
physical read requests..................95
segment scans...........................1
-
-
------------------------------------------------------------------------------
------------------------------------------------------------------------------
###                 Again _very_large_object_threshold + 1: 41736 blocks
-
################     Results:      ##################
Run #  01 ran in 6 hsecs
##########################################################
Statistics                               | Run # 1
##########################################################
physical reads cache.................... |              1
physical reads direct................... |          2,491
index fast full scans (full)............ |              1
index fast full scans (direct read)..... |              1
##########################################################
-
logical reads...........................2496
physical reads..........................2492
physical read requests..................86
physical reads direct...................2491
segment scans...........................1
-
-
------------------------------------------------------------------------------
------------------------------------------------------------------------------
###                 Again _very_large_object_threshold: 41735 blocks
-
################     Results:      ##################
Run #  01 ran in 7 hsecs
##########################################################
Statistics                               | Run # 1
##########################################################
physical reads cache.................... |          2,494
physical reads direct................... |              0
index fast full scans (full)............ |              1
index fast full scans (direct read)..... |              0
##########################################################
-
logical reads...........................2496
physical reads..........................2494
physical read requests..................95
segment scans...........................1

PL/SQL procedure successfully completed.

Formating and Exporting a Report Column

Denes Kubicek - Sat, 2013-03-16 04:54
Sometimes you need to format a report column and if you need to do that in the report SQL, you will be faced with a problem while exporting the report - the formatted values will be exported 1:1 and you will see those ugly html tags among the exported data. In early days of APEX people recommended using two columns - one to display in a report and hide it while exporting and one hidden column used for exports only instead. You would then use a condition like this:

apex_application.g_excel_format = FALSE

to says not to export or the opposite one:

apex_application.g_excel_format = TRUE

to say to export.This solution may work with a standard report but it can't be used efficiently with Interactive Reports.

Just in case you didn't know, you can solve that problem easily. See this example at apex.oracle.com. There, I am using a function to format a string and use the value of the current request to see if the report is simply getting rendered on the page or exported. If the report is exported, I will not use the formatting tags and return the values as it was parsed.



Categories: Development

Scrabble Puzzle

FeuerThoughts - Fri, 2013-03-15 14:03
I like Scrabble, for many reasons.

I like words. I like to write. I like to read.

But one of the things I like best about Scrabble is how it is so much like life.

Every time I play a game of Scrabble, something totally amazing about the pattern of play in that game will strike me:

"Check it out! Ten turns and not a single letter E was used!"

"Whoa, that's amazing. Every word that contains an A also contains the letter I!"

and so on.

So why do I say Scrabble is like life? Because both Scrabble and life are filled with patterns that seem to be very amazing and profound, but in fact are meaningless, nothing more than coincidences to which our brain happens to be attuned.

OK, time for the Scrabble Puzzle:

A week ago, I played a game of Scabble with Veva and scored 36 points by placing the word "SEEN" on the board.

Now, every letter in "SEEN" is worth 1 point, making it very difficult to get to 36 points. But I attached "SEEN" to a word on the board (of course!) and I got my 36 points by using a total of 8 letters, two of which were worth 3 points and the other 5 were worth 1 point each.

Still not a whole lot of points to work from.

So how was I able to get to 36 points? I will post the answer next week.
Categories: Development

APEX Collections and Joins

Denes Kubicek - Thu, 2013-03-14 05:55
APEX Collections is one of the best features of APEX. There are situations where solutions wouldn't be possible if this feature would not be available. However, the collections have some limitations. One of the limitations is if you need to store number values and use those values to join a collection with other tables. The consequences may be that you receive something like

ORA-01722: invalid number


The strange thing with this error is that it may occur sporadic and you can't realy understand why it happens. If you operate on different systems (development, testing, production) you may receive this error on one of the instances and never on the other one. I asked Patrick Wolf about the reasons and he answered that this has to do with the way the cost based optimizer works. If it uses a different plan from the one you would expect, it may find non numeric values in the same column comming from a different collection. In that case the solution is to use the numeric columns in the collection (n0xx) for storing numeric values used in later joins.
Categories: Development

Unresolved quiz: Avoiding in-list iterator

XTended Oracle SQL - Wed, 2013-03-13 16:34

A couple days ago i had very interesting quiz, which is not resolved yet.
Look at this simplified query:

  select *
  from xt1,xt2
  where
       xt1.b=10
   and xt1.a=xt2.a
   and xt2.b in (1,2);

PLAN_TABLE_OUTPUT
----------------------------------------------------------------------------------------
Plan hash value: 2715236140

----------------------------------------------------------------------------------------
| Id  | Operation                     | Name   | Rows  | Bytes | Cost (%CPU)| Time     |
----------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT              |        |   100 | 36900 |   501   (0)| 00:00:07 |
|   1 |  NESTED LOOPS                 |        |       |       |            |          |
|   2 |   NESTED LOOPS                |        |   100 | 36900 |   501   (0)| 00:00:07 |
|   3 |    TABLE ACCESS BY INDEX ROWID| XT1    |   100 | 31000 |   101   (0)| 00:00:02 |
|*  4 |     INDEX RANGE SCAN          | IX_XT1 |   100 |       |     1   (0)| 00:00:01 |
|   5 |    INLIST ITERATOR            |        |       |       |            |          |
|*  6 |     INDEX RANGE SCAN          | IX_XT2 |     1 |       |     3   (0)| 00:00:01 |
|   7 |   TABLE ACCESS BY INDEX ROWID | XT2    |     1 |    59 |     4   (0)| 00:00:01 |
----------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   4 - access("XT1"."B"=10)
   6 - access("XT1"."A"="XT2"."A" AND ("XT2"."B"=1 OR "XT2"."B"=2))

Spoiler:: Full test case SelectShow

create table xt1 as
select 
   level a
 , mod(level,1000) b
 , lpad(1,300,1) padding 
from dual
connect by level<=1e5;

create index ix_xt1 on xt1(b);

create table xt2 as
select 
   level        a
 , mod(level,5) b
 , lpad(1,50,1) padding 
from dual
connect by level<=1e6;

alter table xt2 
  add constraint uq_xt2
  unique (a)
  using index(create index ix_xt2 on xt2(a,b));

exec dbms_stats.gather_table_stats('','XT1',cascade=>true);
exec dbms_stats.gather_table_stats('','XT2',cascade=>true);

explain plan for 
select *
from xt1,xt2
where 
     xt1.b=10
 and xt1.a=xt2.a
 and xt2.b in (1,2);

@?/rdbms/admin/utlxpls.sql


As you see, in such queries cbo always generating plans with INLIST ITERATOR, and it is reasonably in cases when there are many rows with different values of field B for most values of A, and this number is much larger than number of values in the “INLIST”. But in such case as shown, will be better to use index range scan with access by A and filter by B:

SQL> select *
  2  from xt1,xt2
  3  where
  4       xt1.b=10
  5   and xt1.a=xt2.a
  6   and xt2.b in (1,2);

no rows selected

Statistics
----------------------------------------------------------
        ...
        505  consistent gets
SQL> -- without inlist iterator:
SQL> select *
  2  from xt1,xt2
  3  where
  4       xt1.b=10
  5   and xt1.a=xt2.a
  6   and xt2.b+0 in (1,2);

no rows selected

Statistics
----------------------------------------------------------
        ...
        305  consistent gets

But how we can do it? I know 5 options:
1. Trace event 10157
2. Rewrite code. for example replacing “b in (1,2)” to “b+0 in (1,2)”
3. Changing query with “Advanced query rewrite” (DBMS_ADVANCED_REWRITE.DECLARE_REWRITE_EQUIVALENCE)
4. Recreating index from xt2(a,b) to xt2(a,1,b)
5. Changing optimizer_mode to “rule” through hint or SQL profile/baseline

But unfortunately all of them are inapplicable for the my real problem, because i cannot for some reasons rewrite query or change query with advanced rewrite, cannot recreate/add index, and can’t change optimizer_mode, because execution plan for the real query will become worst than plan generated with CBO with inlist iterator(some operations aren’t exists in RBO).

Could anybody suggest any another solution?