In table-dropdownkey and dropdown index

HI
i have a atable UI ,in which one column contains dropdowns in this case which is recommended drop down by key or dropdown by index.
Thanks
rahul

Hi,
In general, you can refer to SAP Library for UI Element Guide (for 7.1 release) at below link:-
http://help.sap.com/saphelp_nwce711/helpdata/en/9f/656442a1c4de54e10000000a155106/frameset.htm
Kind Regards,
Nitin

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Table partitioning and global indexing

hello all,
the requirement is to do table partitioning with global indexing! & also thr r almost 60 crores of rows are there! so can you tell me the way which can be done better and also please provide me the procedure with documents?
thanks in advance!

Hi,
have a look at online redefinition of a table, see Oracle Manual (10.2): http://download.oracle.com/docs/cd/B19306_01/server.102/b14231/tables.htm#ADMIN01514
The steps are described in the manual.
Herald ten Dam
Superconsult.nl

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After reading your response it appears that my real problem has to do with checking pointing. I've included below a copy of the error message:
Oracle process number: 8
Windows thread id: 3768, image: ORACLE.EXE (CKPT)
*** 2008-07-27 16:50:13.569
*** SERVICE NAME:(SYS$BACKGROUND) 2008-07-27 16:50:13.569
*** SESSION ID:(219.1) 2008-07-27 16:50:13.569
ORA-00206: Message 206 not found; No message file for product=RDBMS, facility=ORA; arguments: [3] [1]
ORA-00202: Message 202 not found; No message file for product=RDBMS, facility=ORA; arguments: [D:\ELLIPSE_DATABASE\CONTROL\CTRL1_ELLPROD1.CTL]
ORA-27072: Message 27072 not found; No message file for product=RDBMS, facility=ORA
OSD-04008: WriteFile() failure, unable to write to file
O/S-Error: (OS 33) The process cannot access the file because another process has locked a portion of the file.
error 221 detected in background process
ORA-00221: Message 221 not found; No message file for product=RDBMS, facility=ORA
ORA-00206: Message 206 not found; No message file for product=RDBMS, facility=ORA; arguments: [3] [1]
ORA-00202: Message 202 not found; No message file for product=RDBMS, facility=ORA; arguments: [D:\ELLIPSE_DATABASE\CONTROL\CTRL1_ELLPROD1.CTL]
ORA-27072: Message 27072 not found; No message file for product=RDBMS, facility=ORA
OSD-04008: WriteFile() failure, unable to write to file
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Can you tell me why I'm having issues with checking point and the control file?
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Thanks

WebDynpro Java: how to remove blank element from Table and Dropdown.

Hi Folks
In a webdynpro application,
I created a table and witten the below code to populate the table
     IPrivateDummyView.IFirst_TableElement First_Table_Element = null;
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As per the code, i got 2 row in the table.
But , i have one Empty row on top of the table , how to get ride of this.
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>
> how to remove blank element from Table and Dropdown
>
Change selection property of related node to from 0..1 to 1..1 (mandatory)
Re: DropdownByIndex and empty line (Thread: DropdownByIndex and empty line )
Re: Can the empty selection be removed from element dropdownbykey(Thread: Can the empty selection be removed from element dropdownbykey )
Edited by: Anagha Jawalekar on Nov 18, 2008 10:28 PM

Analyzing tables and all index

hi
What is the command to analyze the tables and all indexes and columns for a particular table
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rajesh

9i and 10g:
exec dbms_stats.gather_table_stats('<schema>' , '<table_name>', cascade=>true);

INITRANS mismatch for Table and its indexes

What will happen if the INITRANS for a table is set as 50 and its index is set as 2?
The number of simultaneous inserts is 32.
Thanks in advance
Aji

This is an example that Oracle performs leaf node splits instead of waiting for ITL:
SQL> SQL> drop table t cascade constraints purge;
Table dropped.
SQL> create table t(id int, pad char(50));
Table created.
SQL> insert into t select rownum, 'x' from dual connect by level <= 150;
150 rows created.
SQL> create index t_indx on t(pad) pctfree 0;
Index created.
SQL> analyze index t_indx validate structure;
Index analyzed.
SQL> select lf_rows, lf_blks from index_stats;
   LF_ROWS    LF_BLKS
       150          2
SQL> set serveroutput on
SQL>
SQL> select name, value from v$statname n, v$sesstat s
2   where name like '%splits%'
3     and sid = userenv('sid')
4     and n.statistic# = s.statistic#;
NAME                                                                  VALUE
leaf node splits                                                          0
leaf node 90-10 splits                                                    0
branch node splits                                                        0
queue splits                                                              0
SQL>
SQL> declare
2      procedure do_update(p_id number)
3      is
4          pragma autonomous_transaction;
5      begin
6          update t set pad = 'y' where id = p_id;
7          if p_id <= 35 then
8              do_update(p_id + 1);
9          end if;
10          commit;
11      end;
12 begin
13      do_update(1);
14 end;
15 /
PL/SQL procedure successfully completed.
SQL>
SQL> select name, value from v$statname n, v$sesstat s
2   where name like '%splits%'
3     and sid = userenv('sid')
4     and n.statistic# = s.statistic#;
NAME                                                                  VALUE
leaf node splits                                                          1
leaf node 90-10 splits                                                    0
branch node splits                                                        0
queue splits                                                              0
SQL>
SQL> analyze index t_indx validate structure;
Index analyzed.
SQL> select lf_rows, lf_blks from index_stats;
   LF_ROWS    LF_BLKS
       186          3
SQL> select statistic_name, value from v$segment_statistics where object_name = 'T' and owner=user;
STATISTIC_NAME                                                        VALUE
logical reads                                                           176
buffer busy waits                                                         0
gc buffer busy                                                            0
db block changes                                                        688
physical reads                                                            0
physical writes                                                           0
physical reads direct                                                     0
physical writes direct                                                    0
gc cr blocks received                                                     0
gc current blocks received                                                0
ITL waits                                                                 0
row lock waits                                                            0
space used                                                                0
space allocated                                                     1048576
segment scans                                                             0
15 rows selected.But increasing number of concurrent transactions fails with a deadlock:
SQL> declare
2      procedure do_update(p_id number)
3      is
4          pragma autonomous_transaction;
5      begin
6          update t set pad = 'y' where id = p_id;
7          if p_id <= 50 then
8              do_update(p_id + 1);
9          end if;
10          commit;
11      end;
12 begin
13      do_update(1);
14 end;
15 /
declare
ERROR at line 1:
ORA-00060: deadlock detected while waiting for resource
ORA-06512: at line 6
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8
ORA-06512: at line 8V$SEGMENT_STATISTICS does not reflect ITL waits (but they present in generated trace file) and leaf block split still happens. I don't know how to explain this.

Difference between dropdown index

Hi,
Pls tell me the dif between dropdown by index and dropdown by key?

Hi,
DRP BY INDEX is used to have the custom dropdowns. Based on some condition, if you want to fill the dropdown
dynamically then this is used.
DRPBY KEY this is usaually used when we have values at DOMAIN level as fixedvalues, VALUE table.
Go through these links -
http://help.sap.com/saphelp_nw2004s/helpdata/en/dd/b0884118aa1709e10000000a155106/content.htm
http://help.sap.com/saphelp_nw2004s/helpdata/en/c5/e4884180951809e10000000a155106/content.htm
Regards,
Lekha.

ABAP-- diff between sy-sy-tabix and sy-index

Hi Guru's,
Pleae can anybody expalins me what is the difference between sy-tabix and sy-index(Loop Index) ?
Because in one case i am Modifyimg the internal table inside the do loop by giving sy-index ((Index of Internal Tables)(MODIFY scarr_tab INDEX sy-index FROM scarr_wa TRANSPORTING currcode. ) in the syntax and in other case inside loop statement i am modifyng same record by giving sy-tabix MODIFY scarr_tab INDEX sy-tabix FROM scarr_wa TRANSPORTING currcode.) in the syntax.
in both cases its working fine but i am not getting which one i have to use where to modify the internal table?
regards
SATYA

Hi Henry,
SY-INDEX is the value of the current iteration. It is applicable for the following programming constructs in ABAP -
DO...ENDDO.
WHILE...ENDWHILE.
SY-TABIX (TABle IndeX) is applicable to internal tables. If you scroll down in the link which Eddie has given, you will find a more detailed explanation for sy-tabix and which statements affect its value.
Regards,
Anand Mandalika.

Difference between sy-tabix and sy-index?

tell me about sy-tabix and sy-index?what is the difference between sy-tabix and sy-index?
Moderator Message: Please search before posting. Read the [Forum Rules Of Engagement |https://wiki.sdn.sap.com/wiki/display/HOME/RulesofEngagement] for further details.
Edited by: Suhas Saha on Jun 18, 2011 5:33 PM

HI,
Here is a brief description of difference between SY_TABIX and SY_INDEX and using them with several conditions.
SY-TABIX
Current line of an internal table. SY-TABIX is set by the statements below, but only for index tables. The field is either not set or is set to 0 for hashed tables.
APPEND sets SY-TABIX to the index of the last line of the table, that is, it contains the overall number of entries in the table.
COLLECT sets SY-TABIX to the index of the existing or inserted line in the table. If the table has the type HASHED TABLE, SY-TABIX is set to 0.
LOOP AT sets SY-TABIX to the index of the current line at the beginning of each loop lass. At the end of the loop, SY-TABIX is reset to the value that it had before entering the loop. It is set to 0 if the table has the type HASHED TABLE.
READ TABLE sets SY-TABIX to the index of the table line read. If you use a binary search, and the system does not find a line, SY-TABIX contains the total number of lines, or one more than the total number of lines. SY-INDEX is undefined if a linear search fails to return an entry.
SEARCH <itab> FOR sets SY-TABIX to the index of the table line in which the search string is found.
SY-INDEX
In a DO or WHILE loop, SY-INDEX contains the number of loop passes including the current pass.
Hope this helps.
Thank you,
Pavan.

Access path difference between Primary Key and Unique Index

Hi All,
Is there any specific way the oracle optimizer treats Primary key and Unique index differently?
Oracle Version
SQL> select * from v$version;
BANNER
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
PL/SQL Release 11.2.0.3.0 - Production
CORE    11.2.0.3.0      Production
TNS for IBM/AIX RISC System/6000: Version 11.2.0.3.0 - Production
NLSRTL Version 11.2.0.3.0 - Production
SQL> Sample test data for Normal Index
SQL> create table t_test_tab(col1 number, col2 number, col3 varchar2(12));
Table created.
SQL> create sequence seq_t_test_tab start with 1 increment by 1 ;
Sequence created.
SQL> insert into t_test_tab select seq_t_test_tab.nextval, round(dbms_random.value(1,999)) , 'B'||round(dbms_random.value(1,50))||'A' from dual connect by level < 100000;
99999 rows created.
SQL> commit;
Commit complete.
SQL> exec dbms_stats.gather_table_stats(USER_OWNER','T_TEST_TAB',cascade => true);
PL/SQL procedure successfully completed.
SQL> select col1 from t_test_tab;
99999 rows selected.
Execution Plan
Plan hash value: 1565504962
| Id | Operation         | Name       | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT |            | 99999 |   488K|    74   (3)| 00:00:01 |
|   1 | TABLE ACCESS FULL| T_TEST_TAB | 99999 |   488K|    74   (3)| 00:00:01 |
Statistics
          1 recursive calls
          0 db block gets
       6915 consistent gets
        259 physical reads
          0 redo size
    1829388 bytes sent via SQL*Net to client
      73850 bytes received via SQL*Net from client
       6668 SQL*Net roundtrips to/from client
          0 sorts (memory)
          0 sorts (disk)
      99999 rows processed
SQL> create index idx_t_test_tab on t_test_tab(col1);
Index created.
SQL> exec dbms_stats.gather_table_stats('USER_OWNER','T_TEST_TAB',cascade => true);
PL/SQL procedure successfully completed.
SQL> select col1 from t_test_tab;
99999 rows selected.
Execution Plan
Plan hash value: 1565504962
| Id | Operation         | Name       | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT |            | 99999 |   488K|    74   (3)| 00:00:01 |
|   1 | TABLE ACCESS FULL| T_TEST_TAB | 99999 |   488K|    74   (3)| 00:00:01 |
Statistics
          1 recursive calls
          0 db block gets
       6915 consistent gets
          0 physical reads
          0 redo size
    1829388 bytes sent via SQL*Net to client
      73850 bytes received via SQL*Net from client
       6668 SQL*Net roundtrips to/from client
          0 sorts (memory)
          0 sorts (disk)
      99999 rows processed
SQL> Sample test data when using Primary Key
SQL> create table t_test_tab1(col1 number, col2 number, col3 varchar2(12));
Table created.
SQL> create sequence seq_t_test_tab1 start with 1 increment by 1 ;
Sequence created.
SQL> insert into t_test_tab1 select seq_t_test_tab1.nextval, round(dbms_random.value(1,999)) , 'B'||round(dbms_random.value(1,50))||'A' from dual connect by level < 100000;
99999 rows created.
SQL> commit;
Commit complete.
SQL> exec dbms_stats.gather_table_stats('USER_OWNER','T_TEST_TAB1',cascade => true);
PL/SQL procedure successfully completed.
SQL> select col1 from t_test_tab1;
99999 rows selected.
Execution Plan
Plan hash value: 1727568366
| Id | Operation         | Name        | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT |             | 99999 |   488K|    74   (3)| 00:00:01 |
|   1 | TABLE ACCESS FULL| T_TEST_TAB1 | 99999 |   488K|    74   (3)| 00:00:01 |
Statistics
          1 recursive calls
          0 db block gets
       6915 consistent gets
          0 physical reads
          0 redo size
    1829388 bytes sent via SQL*Net to client
      73850 bytes received via SQL*Net from client
       6668 SQL*Net roundtrips to/from client
          0 sorts (memory)
          0 sorts (disk)
      99999 rows processed
SQL> alter table t_test_tab1 add constraint pk_t_test_tab1 primary key (col1);
Table altered.
SQL> exec dbms_stats.gather_table_stats('USER_OWNER','T_TEST_TAB1',cascade => true);
PL/SQL procedure successfully completed.
SQL> select col1 from t_test_tab1;
99999 rows selected.
Execution Plan
Plan hash value: 2995826579
| Id | Operation            | Name           | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT     |                | 99999 |   488K|    59   (2)| 00:00:01 |
|   1 | INDEX FAST FULL SCAN| PK_T_TEST_TAB1 | 99999 |   488K|    59   (2)| 00:00:01 |
Statistics
          1 recursive calls
          0 db block gets
       6867 consistent gets
          0 physical reads
          0 redo size
    1829388 bytes sent via SQL*Net to client
      73850 bytes received via SQL*Net from client
       6668 SQL*Net roundtrips to/from client
          0 sorts (memory)
          0 sorts (disk)
      99999 rows processed
SQL> If you see here the even though statistics were gathered,
     * In the 1st table T_TEST_TAB, the table is still using FULL table access after creation of index.
     * And in the 2nd table T_TEST_TAB1, table is using PRIMARY KEY as expected.
Any comments ??
Regards,
BPat

Thanks.
Yes, ignored the NOT NULL part.Did a test and now it is working as expected
SQL> create table t_test_tab(col1 number not null, col2 number, col3 varchar2(12));
Table created.
SQL>
create sequence seq_t_test_tab start with 1 increment by 1 ;SQL>
Sequence created.
SQL> insert into t_test_tab select seq_t_test_tab.nextval, round(dbms_random.value(1,999)) , 'B'||round(dbms_random.value(1,50))||'A' from dual connect by level < 100000;
99999 rows created.
SQL> commit;
Commit complete.
SQL> exec dbms_stats.gather_table_stats('GREP_OWNER','T_TEST_TAB',cascade => true);
PL/SQL procedure successfully completed.
SQL> set autotrace traceonly
SQL> select col1 from t_test_tab;
99999 rows selected.
Execution Plan
Plan hash value: 1565504962
| Id | Operation         | Name       | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT |            | 99999 |   488K|    74   (3)| 00:00:01 |
|   1 | TABLE ACCESS FULL| T_TEST_TAB | 99999 |   488K|    74   (3)| 00:00:01 |
Statistics
          1 recursive calls
          0 db block gets
       6912 consistent gets
          0 physical reads
          0 redo size
    1829388 bytes sent via SQL*Net to client
      73850 bytes received via SQL*Net from client
       6668 SQL*Net roundtrips to/from client
          0 sorts (memory)
          0 sorts (disk)
      99999 rows processed
SQL> create index idx_t_test_tab on t_test_tab(col1);
Index created.
SQL> exec dbms_stats.gather_table_stats('GREP_OWNER','T_TEST_TAB',cascade => true);
PL/SQL procedure successfully completed.
SQL> select col1 from t_test_tab;
99999 rows selected.
Execution Plan
Plan hash value: 4115006285
| Id | Operation            | Name           | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT     |                | 99999 |   488K|    63   (2)| 00:00:01 |
|   1 | INDEX FAST FULL SCAN| IDX_T_TEST_TAB | 99999 |   488K|    63   (2)| 00:00:01 |
Statistics
          1 recursive calls
          0 db block gets
       6881 consistent gets
          0 physical reads
          0 redo size
    1829388 bytes sent via SQL*Net to client
      73850 bytes received via SQL*Net from client
       6668 SQL*Net roundtrips to/from client
          0 sorts (memory)
          0 sorts (disk)
      99999 rows processed
SQL>

Difference between primary key and primary index

Dear All,
Hi... .Could you pls tell me the difference between primary key and primary index.
Thanks...

Hi,
Primary Key : It is one which makes an entry of the field unique.No two distinct rows in a table can have the same value (or combination of values) in those columns.
Eg: first entry is 111, if you again enter value 111 , it doesnot allow 111 again. similarly for the strings or characters or numc etc. Remember that for char or numc or string 'NAME' is not equal to 'name'.
Primary Index: this is related to the performance .A database index is a data structure that improves the speed of operations in a table. Indices can be created using one or more columns, providing the basis for both rapid random lookups and efficient ordering of access to records. The disk space required to store the index is typically less than the storage of the table (since indices usually contain only the key-fields according to which the table is to be arranged, and excludes all the other details in the table), yielding the possibility to store indices into memory from tables that would not fit into it. In a relational database an index is a copy of part of a table. Some databases extend the power of indexing by allowing indices to be created on functions or expressions. For example, an index could be created on upper(last_name), which would only store the uppercase versions of the last_name field in the index.
In a database , we may have a large number of records. At the time of retrieving data from the database based on a condition , it is a burden to the db server. so whenever we create a primary key , a primary index is automatically created by the system.
If you want to maintain indices on other fields which are frequently used in where condition then you can create secondary indices.
Reward points if helpful.
Thanks,
Sirisha..

Difference between primary eindex and secondary index?

hi experts
pls answer me
difference between primary eindex and secondary index?
rewads apply.
thanks.
naresh.

hi,
check this link.
http://help.sap.com/saphelp_47x200/helpdata/en/cf/21eb2d446011d189700000e8322d00/frameset.htm
A difference is made between Primary & Secondary indexes to a table. the primary index consists of the key fields of the table and a pointer to the non-keys-fields of the table. The Primary index is generated automatically when a table is created and is created in the datebase as the same times as the table. It is also possible to define further indexes to a table in the ABAP/4 dictionary, which are then referred to as Secondary indexes.
Always it is not mandatory that an index should have all the key fields of a table. To see the index of a table
goto SE11->specify table name->click on the indexes... button on the application toolbar.
Based on your requirement you can you any of those index fields in the where clause of your query. Always its a better practice to use the index fields in the order specified. While selecting the records from a table it is always better to select the fields in the same order as specified in the table.

Difference between unique constraint and unique index

1. What is the difference between unique constraint and unique index when unique constraint is always indexed ? Which one is better in this case for better performance ?
2. Is Composite index of 3 columns x,y,z better
or having independent/ seperate indexes on 3 columns x,y,z is better for better performance ?
3. It has been very confusing for me to decide which columns to index, I have indexed most foreignkey columns, is it a good idea ? We do lot of selects and DMLS on most of our tables. Is there any query that I can run and find out if indexes are really being used and if they are improving any performance. I have analyzed and computed my indexes using ANALYZE index index_name validate structure and COMPUTE STATISTICS;
null

1. Unique index is part of unique constraint. Of course you can create standalone unique index. But is is no point to skip the logical view of business if you spend same effort to achive.
You create unique const. Oracle create the unique index for you. You may specify index characteristic in unique constraint.
2. Depends. You can't utilize the composite index if the searching condition is not whole or front part of the indexing key. You can't utilize your index if you query the table for y=2. That is.
3. As old words in database arena, Index may be good or bad for a table depending on the size of table, number of columns in the table... etc. It is very environmental dependent. In fact, It is part of database nomalization. Statistic is a way oracle use to determine the execution plan.
Steve
null

What's difference between ASC and DESC index

1 select count(*)
2* from big_emp e where hiredate >= to_date('1980-01-01', 'YYYY-MM-DD') and hiredate <= to_date('1983-12-31', 'YYYY-MM-DD')
COUNT(*)
11971
SQL> create index i_big_emp_hiredate on big_emp(hiredate);
Index created.
SQL> set autot trace
SQL> select empno, ename, hiredate
2 from big_emp e where hiredate >= to_date('1980-01-01', 'YYYY-MM-DD') and hiredate <= to_date('1983-12-31', 'YYYY-MM-DD') ;
11971 rows selected.
Execution Plan
| Id | Operation | Name | Rows | Bytes | Cost |
| 0 | SELECT STATEMENT | | 11766 | 218K| 19 |
|* 1 | TABLE ACCESS FULL| BIG_EMP | 11766 | 218K| 19 |
SQL> drop index i_big_emp_hiredate;
Index dropped.
SQL> create index i_big_emp_hiredate on big_emp(hiredate desc);
Index created.
SQL> select empno, ename, hiredate
2 from big_emp e where hiredate >= to_date('1980-01-01', 'YYYY-MM-DD') and hiredate <= to_date('1983-12-31', 'YYYY-MM-DD') ;
11971 rows selected.
Execution Plan
| Id | Operation | Name | Rows | Bytes | Cost |
| 0 | SELECT STATEMENT | | 29 | 551 | 4 |
| 1 | TABLE ACCESS BY INDEX ROWID| BIG_EMP | 29 | 551 | 4 |
|* 2 | INDEX RANGE SCAN | I_BIG_EMP_HIREDATE | 53 | | 2 |
i have 2 questions
1. In "Expert one-on-one Oracle", Tom said, there is no deference between ASC and DESC index in case of one column because Oracle can just read in reverse order. but my test made me confused. why Oracle did "full table scan" only in ASC index???
2. using "set autot trace" command. i believed the the "Rows" column mean the rows that Oracle access. Can you explain why the rows are 29(DESC) and 11766(ASC) in spite of the result is 11971. what is the exact meaning of "Rows" column in execution plan

I think what you're seeing is a bug in the optimizer. If you had printed up the predicate section of the execution plan, this would be more obvious. I have the query:
select *
from   t1
where d1 between to_date('01-jan-2001')
          and     to_date('31-dec-2003')
;This returns one row per day for 3 years, and when a normal index is created on it, the optimizer calculates the correct cardinality and uses a sensible set of predicates. But when I use a descending index, this is what I get:
Execution Plan
Plan hash value: 1429545322
| Id | Operation                   | Name | Rows | Bytes | Cost |
|   0 | SELECT STATEMENT            |       | 1097 | 21940 |     2 |
|   1 | TABLE ACCESS BY INDEX ROWID| T1    | 1097 | 21940 |     2 |
|* 2 |   INDEX RANGE SCAN          | T1_I1 |     5 |       |     2 |
Predicate Information (identified by operation id):
   2 - access(SYS_OP_DESCEND("D1")>=HEXTORAW('8798F3E0FEF8FEFAFF') AND
              SYS_OP_DESCEND("D1")<=HEXTORAW('879AFEF8FEF8FEFAFF') )
       filter(SYS_OP_UNDESCEND(SYS_OP_DESCEND("D1"))>=TO_DATE('2001-01-0
              1 00:00:00', 'yyyy-mm-dd hh24:mi:ss') AND
              SYS_OP_UNDESCEND(SYS_OP_DESCEND("D1"))<=TO_DATE('2003-12-31 00:00:00',
              'yyyy-mm-dd hh24:mi:ss'))Note the introduction of the strange sys_op_descend() function - which is related to the descending index implemention, and the extra FILTER predicates which introduce a significant extra selectivity effect. The optimizer is double-counting on selectivity effects, and introducing extra factors of 1% and 5% (I haven't checked exact details) due to the functions applied to columns and the range-based predicates.
Regards
Jonathan Lewis
http://jonathanlewis.wordpress.com
http://www.jlcomp.demon.co.uk

What is Short Dump Analysis and secendry index ?

Dear Experts .
1.) What is purpose of T-codes SE30 and ST22 ?
What is Short Dump Analysis ?
2.) What is secendry index , How to use it ? How it effects the Performance of a report ?
Please it is urgent ...
Regards : Rajneesh

Hi
A dump analysis is a comprehensive list that should enable you to identify the causes and possible solutions of program errors. The ABAP Workbench generates a short dump whenever a report or transaction terminates due to a serious error. The system enters the error in the system log and writes a snapshot of the program at the moment when it terminated into a special database table called SNAP.
Dump analyses give the user or programmer information about the causes of the error that has caused the program to terminate. Experienced users can use them to identify very quickly where and why this occurred. He or she can them solve the problem.
The snapshot contains the following information:
Why the program has terminated
What caused the program termination
Where in the program code the termination occurred
What you can do to correct the error
The values of the relevant system fields when the program terminated
The calls or events that were active when the program terminated
Any other programs that are affected.
http://help.sap.com/saphelp_nw70/helpdata/en/c6/617d0ce68c11d2b2ab080009b43351/content.htm
Index: Technical key of a database table.
Primary index: The primary index contains the key fields of the table and a pointer to the non-key fields of the table. The primary index is created automatically when the table is created in the database.
Secondary index: Additional indexes could be created considering the most frequently accessed dimensions of the table.
Structure of an Index
An index can be used to speed up the selection of data records from a table.
An index can be considered to be a copy of a database table reduced to certain fields. The data is stored in sorted form in this copy. This sorting permits fast access to the records of the table (for example using a binary search). Not all of the fields of the table are contained in the index. The index also contains a pointer from the index entry to the corresponding table entry to permit all the field contents to be read.
When creating indexes, please note that:
An index can only be used up to the last specified field in the selection! The fields which are specified in the WHERE clause for a large number of selections should be in the first position.
Only those fields whose values significantly restrict the amount of data are meaningful in an index.
When you change a data record of a table, you must adjust the index sorting. Tables whose contents are frequently changed therefore should not have too many indexes.
Make sure that the indexes on a table are as disjunctive as possible.
(That is they should contain as few fields in common as possible. If two indexes on a table have a large number of common fields, this could make it more difficult for the optimizer to choose the most selective index.)
Accessing tables using Indexes
The database optimizer decides which index on the table should be used by the database to access data records.
You must distinguish between the primary index and secondary indexes of a table. The primary index contains the key fields of the table. The primary index is automatically created in the database when the table is activated. If a large table is frequently accessed such that it is not possible to apply primary index sorting, you should create secondary indexes for the table.
The indexes on a table have a three-character index ID. '0' is reserved for the primary index. Customers can create their own indexes on SAP tables; their IDs must begin with Y or Z.
If the index fields have key function, i.e. they already uniquely identify each record of the table, an index can be called a unique index. This ensures that there are no duplicate index fields in the database.
When you define a secondary index in the ABAP Dictionary, you can specify whether it should be created on the database when it is activated. Some indexes only result in a gain in performance for certain database systems. You can therefore specify a list of database systems when you define an index. The index is then only created on the specified database systems when activated

In table-dropdownkey and dropdown index

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