doubt about the Index Skip Scan

Similar Questions

• Doubt about the Index

  Hi all
  
  Oracle Database 11 g Enterprise Edition Release 11.2.0.2.0 - 64 bit Production
  PL/SQL Release 11.2.0.2.0 - Production
  "CORE 11.2.0.2.0 Production."
  AMT for Linux: Version 11.2.0.2.0 - Production
  NLSRTL Version 11.2.0.2.0 - Production
  
  I have a question about the index. Is - this required that the index will be useful if we have a "WHERE" clause I tried to find myself there but do not.
  In this example I haven't used where clause used but group. But it gives a comprehensive analysis. Is it possible to get the scan interval or something else using Group by?
  

  SELECT tag_id FROM taggen.tag_master GROUP by tag_id 
  
  Explain Plan:
  Plan hash value: 1688408656
   
  ---------------------------------------------------------------------------------------
  | Id  | Operation             | Name          | Rows  | Bytes | Cost (%CPU)| Time     |
  ---------------------------------------------------------------------------------------
  |   0 | SELECT STATEMENT      |               |  4045 | 20225 |     6  (17)| 00:00:01 |
  |   1 |  HASH GROUP BY        |               |  4045 | 20225 |     6  (17)| 00:00:01 |
  |   2 |   INDEX FAST FULL SCAN| TAG_MASTER_PK |  4045 | 20225 |     5   (0)| 00:00:01 |
  ---------------------------------------------------------------------------------------

  Hello

  SamFisher wrote:
  Since I was on what they do full scan. Is it possible to restrict of fullscan without using where clause?
  I guess having limit clause but not quite know.

  Why?
  If this query is producing good results, then you need a full analysis.
  If fool you somehow the optimizer by doing a scan of interval, it will be slower.

• INDEX RANGE SCAN against INDEX SKIP SCAN

  Dear,
  
  Let me introduce you to the model, and then I'll ask my question
  

  SQL> select * from v$version;
  
  BANNER
  ----------------------------------------------------------------
  Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi
  PL/SQL Release 10.2.0.5.0 - Production
  CORE    10.2.0.5.0      Production
  TNS for Solaris: Version 10.2.0.5.0 - Production
  NLSRTL Version 10.2.0.5.0 - Production
  
  SQL> create table t1
    2     as select rownum                  id1,
    3      mod(rownum,1000)                  id2,
    4      lpad(rownum,10,'0')              small_vc,
    5      rpad('x',1000)                   padding
    6  from dual
    7  connect by level <= 10000;
  
  Table created.
  
  SQL> create index t1_ind_id1 on t1(id1);
  
  Index created.
  
  SQL> create index t1_ind_id2 on t1(id2, id1);
  
  Index created.
  
  SQL> exec dbms_stats.gather_table_stats(user, 't1', cascade => true);
  
  PL/SQL procedure successfully completed.
  
  SQL> select index_name, num_rows, clustering_factor
    2  from user_indexes
    3  where index_name in ('T1_IND_ID1','T1_IND_ID2');
  
  INDEX_NAME                       NUM_ROWS CLUSTERING_FACTOR
  ------------------------------ ---------- -----------------
  T1_IND_ID1                          10000              1429
  T1_IND_ID2                          10000             10000
  
  
  SQL> select *
    2  from t1
    3  where id1=6;
  
   Execution Plan
  ----------------------------------------------------------
  Plan hash value: 2367654148
  
  ------------------------------------------------------------------------------------------
  | Id  | Operation                   | Name       | Rows  | Bytes | Cost (%CPU)| Time     |
  ------------------------------------------------------------------------------------------
  |   0 | SELECT STATEMENT            |            |     1 |  1019 |     2   (0)| 00:00:01 |
  |   1 |  TABLE ACCESS BY INDEX ROWID| T1         |     1 |  1019 |     2   (0)| 00:00:01 |
  |*  2 |   INDEX RANGE SCAN          | T1_IND_ID1 |     1 |       |     1   (0)| 00:00:01 |
  ------------------------------------------------------------------------------------------
  
  Predicate Information (identified by operation id):
  ---------------------------------------------------
  
     2 - access("ID1"=6)

  So far so good.
  
  What I want is to know how I can reproduce an example of real life where an index skip scan has been chosen by the CBO despite the presence of the index 'adequate '.
  
  Here, below, I tried several examples

  SQL> alter index t1_ind_id1 unusable;
  
  Index altered.
  
  SQL> select *
    2  from t1
    3  where id1=6;
  
    Execution Plan
  ----------------------------------------------------------
  Plan hash value: 2497247906
  
  ------------------------------------------------------------------------------------------
  | Id  | Operation                   | Name       | Rows  | Bytes | Cost (%CPU)| Time     |
  ------------------------------------------------------------------------------------------
  |   0 | SELECT STATEMENT            |            |     1 |  1019 |  1004   (1)| 00:00:03 |
  |   1 |  TABLE ACCESS BY INDEX ROWID| T1         |     1 |  1019 |  1004   (1)| 00:00:03 |
  |*  2 |   INDEX SKIP SCAN           | T1_IND_ID2 |     1 |       |  1003   (1)| 00:00:03 |
  ------------------------------------------------------------------------------------------
  
  Predicate Information (identified by operation id):
  ---------------------------------------------------
  
     2 - access("ID1"=6)
         filter("ID1"=6)

  It's predictable. Let replace them the usable index and change its grouping factor
  

  SQL> alter index t1_ind_id1 rebuild;
  
  Index altered.
  
  SQL> select *
    2  from t1
    3  where id1=6;
  
       
  Execution Plan
  ----------------------------------------------------------
  Plan hash value: 2367654148
  
  ------------------------------------------------------------------------------------------
  | Id  | Operation                   | Name       | Rows  | Bytes | Cost (%CPU)| Time     |
  ------------------------------------------------------------------------------------------
  |   0 | SELECT STATEMENT            |            |     1 |  1019 |     2   (0)| 00:00:01 |
  |   1 |  TABLE ACCESS BY INDEX ROWID| T1         |     1 |  1019 |     2   (0)| 00:00:01 |
  |*  2 |   INDEX RANGE SCAN          | T1_IND_ID1 |     1 |       |     1   (0)| 00:00:01 |
  ------------------------------------------------------------------------------------------
  
  Predicate Information (identified by operation id):
  ---------------------------------------------------
  
     2 - access("ID1"=6)
  
  SQL> exec dbms_stats.set_index_stats(user, 'T1_IND_ID1',clstfct => 20000);
  
  PL/SQL procedure successfully completed.
  
  SQL> select index_name, num_rows, clustering_factor
    2  from user_indexes
    3  where index_name in ('T1_IND_ID1','T1_IND_ID2');
  
  INDEX_NAME                       NUM_ROWS CLUSTERING_FACTOR
  ------------------------------ ---------- -----------------
  T1_IND_ID1                          10000             20000
  T1_IND_ID2                          10000             10000
  
  
  SQL> select *
    2  from t1
    3  where id1=6;
  
      
  Execution Plan
  ------------------------------------------------------------------------------------------
  Plan hash value: 2367654148
  ------------------------------------------------------------------------------------------
  | Id  | Operation                   | Name       | Rows  | Bytes | Cost (%CPU)| Time     |
  ------------------------------------------------------------------------------------------
  |   0 | SELECT STATEMENT            |            |     1 |  1019 |     3   (0)| 00:00:01 |
  |   1 |  TABLE ACCESS BY INDEX ROWID| T1         |     1 |  1019 |     3   (0)| 00:00:01 |
  |*  2 |   INDEX RANGE SCAN          | T1_IND_ID1 |     1 |       |     1   (0)| 00:00:01 |
  ------------------------------------------------------------------------------------------
  
  Predicate Information (identified by operation id):
  ---------------------------------------------------
  
     2 - access("ID1"=6)

  Still without success to produce an INDEX SKIP SCAN on T1_IND_ID2 in the presence of the T1_IND_ID1 index
  
  Any suggestions?
  
  Thank you
  
  Mohamed Houri
  www.hourim.WordPress.com

  What I want is to know how I can reproduce an example of real life where an index skip scan has been chosen by the CBO despite the presence of the 'adequate' index

  If, on behalf of the investigation, trying to 'force' the index skip scan, you must do two things:

  1. change the factor of grouping of TI_IND_ID1 to make it more expensive.

  While Hemant and Nikolay make good points on the fact that the grouping factor SHOULD BE irrelevant for a search of a single line, you are using a non-unique index is still part of the calculation of costs for a range scan.

  It had been a unique index so the factor of grouping of piracy would have been ineffective.

  But because only the cost calculation involves selectivity * factor clustering, you must change it by an order of magnitude (relevant to num_distinct obviously) to make significant change.

  For example:

  SQL> exec dbms_stats.set_index_stats(user, 'T1_IND_ID1',clstfct => 20000000);
  
  PL/SQL procedure successfully completed.
  
  SQL> explain plan for
    2  select /*+ index(t1 t1_ind_id1) */ *
    3  from t1
    4  where id1=6;
  
  Explained.
  
  SQL> select * from table(dbms_xplan.display);
  
  PLAN_TABLE_OUTPUT
  ---------------------------------------------------------------------------------------------------------
  Plan hash value: 3180815200
  
  ------------------------------------------------------------------------------------------
  | Id  | Operation                   | Name       | Rows  | Bytes | Cost (%CPU)| Time     |
  ------------------------------------------------------------------------------------------
  |   0 | SELECT STATEMENT            |            |     1 |  1019 |  2002   (1)| 00:00:25 |
  |   1 |  TABLE ACCESS BY INDEX ROWID| T1         |     1 |  1019 |  2002   (1)| 00:00:25 |
  |*  2 |   INDEX RANGE SCAN          | T1_IND_ID1 |     1 |       |     1   (0)| 00:00:01 |
  ------------------------------------------------------------------------------------------
  
  Predicate Information (identified by operation id):
  ---------------------------------------------------
  
     2 - access("ID1"=6)
  
  14 rows selected.
  
  SQL>
  

  This pushes the cost of analysis of the range up above the table scan complete:

  SQL> explain plan for
    2  select *
    3  from t1
    4  where id1=6;
  
  Explained.
  
  SQL>  select * from table(dbms_xplan.display);
  
  PLAN_TABLE_OUTPUT
  -----------------------------------------------------------------------------------------------
  Plan hash value: 3617692013
  
  --------------------------------------------------------------------------
  | Id  | Operation         | Name | Rows  | Bytes | Cost (%CPU)| Time     |
  --------------------------------------------------------------------------
  |   0 | SELECT STATEMENT  |      |     1 |  1019 |   322   (1)| 00:00:04 |
  |*  1 |  TABLE ACCESS FULL| T1   |     1 |  1019 |   322   (1)| 00:00:04 |
  --------------------------------------------------------------------------
  
  Predicate Information (identified by operation id):
  ---------------------------------------------------
  
     1 - filter("ID1"=6)
  
  13 rows selected.
  
  SQL>
  

  So, now to the next step.

  2. we need to artificially reduce the cost of the analysis of Skip - and the best way to do that is by changing the separate issue of the main column in the index (currently 1000):

  SQL> begin
    2     DBMS_STATS.SET_COLUMN_STATS
    3     (ownname       => USER,
    4      tabname       => 'T1',
    5      colname       => 'ID2',
    6      partname      => NULL,
    7      stattab       => NULL,
    8      statid        => NULL,
    9      distcnt       => 1,
   10      density       => 1,
   11      nullcnt       => 0,
   12      srec          => NULL,
   13      avgclen       => 4,
   14      flags         => NULL,
   15      statown       => NULL,
   16      no_invalidate => FALSE,
   17      force         => TRUE);
   18  end;
   19  /
  
  PL/SQL procedure successfully completed.
  
  SQL> 
  

  As a Skip Scan is now taken over by default:

  SQL> explain plan for
    2  select *
    3  from t1
    4  where id1=6;
  
  Explained.
  
  SQL> select * from table(dbms_xplan.display);
  
  PLAN_TABLE_OUTPUT
  ---------------------------------------------------------------------------------------------------
  Plan hash value: 3198394326
  
  ------------------------------------------------------------------------------------------
  | Id  | Operation                   | Name       | Rows  | Bytes | Cost (%CPU)| Time     |
  ------------------------------------------------------------------------------------------
  |   0 | SELECT STATEMENT            |            |     1 |  1019 |     3   (0)| 00:00:01 |
  |   1 |  TABLE ACCESS BY INDEX ROWID| T1         |     1 |  1019 |     3   (0)| 00:00:01 |
  |*  2 |   INDEX SKIP SCAN           | T1_IND_ID2 |     1 |       |     2   (0)| 00:00:01 |
  ------------------------------------------------------------------------------------------
  
  Predicate Information (identified by operation id):
  ---------------------------------------------------
  
     2 - access("ID1"=6)
         filter("ID1"=6)
  
  15 rows selected.
  
  SQL>
  

  Hope this helps

  Published by: Dom Brooks on October 24, 2012 12:49
  Reformulated

• Why the feature multiple column indexes using index skip scan?

  Hi all

  I have just been hired by a new company and I explored its database infrastructure. Interestingly, I see several function based indexed column used for all the tables. I found it strange, but they said ' we use Axapta to connect Axapta with Oracle, function index according to should be used to improve performance. Therefore, our DBAs create several indexes of feature based for each table in the database. "Unfortunately, I can not judge their business logic.

  My question is, I just created similar to my local database tables in order to understand the behavior of the function index according to several columns. In order to create indexes of based function (substr and nls_lower), I have to declare the columns as varchars2. Because in my business our DBAs had created a number of columns as a varchar2 data type. I created two excatly same table for my experience. I create miltiple function according to index on the my_first table, and then I create several normal index on the my_sec table. The interesting thing is, index skip scan cannot be performed on more than one basic function index (table my_first). However, it can be performed to normal several index on my_sec table. I hope that I have to express myself clearly.

  Note: I also ask the logic of the rule function based index, they said when they index a column they don't ((column length) * 2 + 1) formula. For example, I want to create indexes on the zip code column, column data type VARCHAR2 (3), so I have to use 3 * 2 + 1 = 7, (substr (nls_lower (areacode), 1, 7). substr (nls_lower ()) notation is used nested for any function function index. I know that these things are very illogical, but they told me, they use this type of implementation for Axapta.

  Anyway, in this thread, my question is reletad to function function with index index skip scan, not logical bussiness, because I can not change the business logic.

  Also, can you please give hints or clues for multiple function based indexes?

  Thanks for your help.

  
  SQL > create table my_first as select '201' codeZone, to_char (100 + rownum) account_num, dbms_random.st
  Ring name ('A', 10) from dual connect by level < = 5000;

  Table created.

  SQL > create table my_sec as select '201' codeZone, to_char (100 + rownum) account_num, dbms_random.st

  Ring name ('A', 10) from dual connect by level < = 5000;

  Table created.

  SQL > alter table my_first change account_num varchar2 (12);

  Modified table.

  
  SQL > alter table my_sec change account_num varchar2 (12);

  Modified table.

  SQL > alter table my_first change codeZone VARCHAR2 (3);

  Modified table.

  SQL > alter table my_sec change codeZone VARCHAR2 (3);

  Modified table.

  SQL > create index my_first_i on my_first (substr (nls_lower (areacode), 1, 7), substr (nls_lower (account_num), 1, 15));

  The index is created.

  SQL > create index my_sec_i on my_sec (area code, account_num);

  The index is created.

  SQL > analyze table my_first computing statistics for all columns indexed for all indexes.

  Parsed table.

  SQL > analyze table my_sec computing statistics for all columns indexed for all indexes.

  Parsed table.

  SQL > exec dbms_stats.gather_table_stats (USER, 'MY_FIRST');

  PL/SQL procedure successfully completed.

  SQL > exec dbms_stats.gather_table_stats (USER, 'MY_SEC');

  PL/SQL procedure successfully completed.

  SQL > my_first desc;
  Name                                      Null?    Type
  ----------------------------------------- -------- ----------------------------
  CODEZONE VARCHAR2 (3)
  ACCOUNT_NUM VARCHAR2 (12)
  NAME VARCHAR2 (4000)

  SQL > desc my_sec
  Name                                      Null?    Type
  ----------------------------------------- -------- ----------------------------
  CODEZONE VARCHAR2 (3)
  ACCOUNT_NUM VARCHAR2 (12)
  NAME VARCHAR2 (4000)

  SQL > select * from my_sec where account_num = '4000';

  
  Execution plan
  ----------------------------------------------------------
  Hash value of plan: 1838048852

  --------------------------------------------------------------------------------
  --------

  | ID | Operation | Name | Lines | Bytes | Cost (% CPU). TI
  me |

  --------------------------------------------------------------------------------
  --------

  |   0 | SELECT STATEMENT |          |     1.    19.     3 (0) | 00
  : 00:01 |

  |   1.  TABLE ACCESS BY INDEX ROWID | MY_SEC |     1.    19.     3 (0) | 00
  : 00:01 |

  |*  2 |   INDEX SKIP SCAN | MY_SEC_I |     1.       |     2 (0) | 00
  : 00:01 |

  --------------------------------------------------------------------------------
  --------

  
  Information of predicates (identified by the operation identity card):
  ---------------------------------------------------

  2 - access ("ACCOUNT_NUM" = '4000')
  Filter ("ACCOUNT_NUM" = '4000')

  
  Statistics
  ----------------------------------------------------------
  1 recursive calls
  0 db block Gets
  Gets 7 compatible
  0 physical reads
  0 redo size
  543 bytes sent via SQL * Net to client
  384 bytes received via SQL * Net from client
  2 SQL * Net back and forth to and from the client
  0 sorts (memory)
  0 sorts (disk)
  1 rows processed

  SQL > select * from my_first where substr (nls_lower (account_num), 1: 25) = '4000';

  
  Execution plan
  ----------------------------------------------------------
  Hash value of plan: 1110109060

  ------------------------------------------------------------------------------
  | ID | Operation | Name | Lines | Bytes | Cost (% CPU). Time |
  ------------------------------------------------------------------------------
  |   0 | SELECT STATEMENT |          |     1.    20.     9 (12) | 00:00:01 |
  |*  1 |  TABLE ACCESS FULL | MY_FIRST |     1.    20.     9 (12) | 00:00:01 |
  ------------------------------------------------------------------------------

  Information of predicates (identified by the operation identity card):
  ---------------------------------------------------

  1 Filter (SUBSTR (NLS_LOWER ("MY_FIRST". "" "" ACCOUNT_NUM")(, 1, 15) ="4000"
  AND SUBSTR (NLS_LOWER ("ACCOUNT_NUM"), 1, 25) = '4000')

  
  Statistics
  ----------------------------------------------------------
  15 recursive calls
  0 db block Gets
  Gets 26 consistent
  0 physical reads
  0 redo size
  543 bytes sent via SQL * Net to client
  384 bytes received via SQL * Net from client
  2 SQL * Net back and forth to and from the client
  0 sorts (memory)
  0 sorts (disk)
  1 rows processed

  SQL > Select / * + INDEX_SS (MY_FIRST) * / * from my_first where substr (nls_lower (account_num), 1: 25) = '4000';

  
  Execution plan
  ----------------------------------------------------------
  Hash value of plan: 2466066660

  --------------------------------------------------------------------------------
  ----------

  | ID | Operation | Name | Lines | Bytes | Cost (% CPU).
  Time |

  --------------------------------------------------------------------------------
  ----------

  |   0 | SELECT STATEMENT |            |     1.    20.    17 (6) |
  00:00:01 |

  |*  1 |  TABLE ACCESS BY INDEX ROWID | MY_FIRST |     1.    20.    17 (6) |
  00:00:01 |

  |*  2 |   INDEX SCAN FULL | MY_FIRST_I |     1.       |    16 (7) |
  00:00:01 |

  --------------------------------------------------------------------------------
  ----------

  
  Information of predicates (identified by the operation identity card):
  ---------------------------------------------------

  1 - filter (SUBSTR (NLS_LOWER ("ACCOUNT_NUM"), 1, 25) = '4000')
  2 - access (SUBSTR (NLS_LOWER ("ACCOUNT_NUM"), 1, 15) = '4000')
  Filter (substr (NLS_LOWER ("ACCOUNT_NUM"), 1, 15) = '4000')

  
  Statistics
  ----------------------------------------------------------
  15 recursive calls
  0 db block Gets
  857 consistent gets
  0 physical reads
  0 redo size
  543 bytes sent via SQL * Net to client
  384 bytes received via SQL * Net from client
  2 SQL * Net back and forth to and from the client
  0 sorts (memory)
  0 sorts (disk)
  1 rows processed

  Check MoS for a bug with the FBI and Skip Scan - it sounds like it could be a bug.

  On 11.2.0.4 with your sample code 10053 trace shows the optimizer whereas an index FULL scan to the point where she should consider an index SKIP scan for "unique table path".

  A person with 12.1.0.1 practice would like to run your test and see if it's fixed in this version.

  Concerning

  Jonathan Lewis

• Question on the composite index and index skip scan

  Hello
  I have a confusion.
  I read the post of Burleson on the column of the composite index command (http://www.dba-oracle.com/t_composite_index_multi_column_ordering.htm) where he writes that
  
  «.. . for composite indexes the most restrictive value of the column (the column with the highest unique values) should be made first to cut down the result set in... »
  
  
  But 10g performance tuning book tells the subject INDEX SKIP SCAN:
  
  "... Index scan Skip allows a composite index that is logically divided into smaller subindex. In Dumpster
  scanning, the first column in the composite index is not specified in the query. In other words, it is ignored.
  The number of logic subindex is determined by the number of distinct values in the first column.
  
  Skip scanning is advantageous if there are few distinct values in the main column of the composite index and many distinct values in the key do not tip of the index... »
  
  If design us a composite index according to what said Burleson, then how can we take advantage of index skip scan. These two staements to oppose each other, Don't they?
  
  Can someone explain this?

  Even if you're not skip scanning, it is best to put the column with less distinct values in the main column of the index.

  If a query specifies two key as predicates of equality columns, it doesn't really matter how columns are sorted in the index.
  If a query specifies a range on a key column, it is most likely on the second column of the index.

  BTW, sometimes even a column 3 or the index of the column 4 is useful. In order to not restrict simply yourself in 2 columns. However, do not create too many clues - especially if there is overlap between the index.

  Hemant K Collette

• Basic query - Index Skip Scan

  Hello
  
  I have a very basic question.
  
  I use Autotrace to check the Plan for this query
  
  Table definition:
  ------------------------------------
  create table tb_emp)
  sextype varchar2 (1).
  EmpID number
  );
  
  Array of values
  -----------------------------------------------
  insert into tb_emp values ('F', 98);
  insert into tb_emp values ('F', 100);
  insert into tb_emp values ('F', 102);
  insert into tb_emp values ('F', 104);
  insert into tb_emp values('M',101);
  insert into tb_emp values('M',103);
  insert into tb_emp values('M',105);
  commit;
  
  Index:
  -----------------------------------------------------------------------------
  create index EMP_SEXTYPE_EMP_IDX on tb_emp (SEXTYPE, empid);
  
  
  Query:
  --------------------------------------------------------------------------------------------------------------
  Select * from tb_emp where empid = 101;
  
  ---------------------------------------------------------------------------------------------------------------
  Execution plan
  ----------------------------------------------------------
  0 SELECT STATEMENT Optimizer = ALL_ROWS (cost = 0 card = 1 bytes = 15)
  1 INDEX 0 (COMPLETE ANALYSIS) OF 'EMP_SEXTYPE_EMP_IDX' (INDEX) (cost = 0 card = 1 bytes = 15)
  
  According to b14211 this should translate into an index Skip Scan,
  
  A pointer to what am I missing or other parameters that could affect the execution plan.
  Thank you and best regards,
  Ashish.

  The case of test used by you is not a real. With 7 records in a table is important if the optimizer goes for a systematic index scan or a full scan?

  make it a little big and try

  SQL> truncate table tb_emp
    2  /
  
  Table truncated.
  
  SQL> set autotrace off
  
  SQL> edit
  Wrote file afiedt.buf
  
    1  insert into tb_emp
    2  select decode(mod(level,2),0,'M','F'), level
    3    from dual
    4* connect by level <= 10000
  SQL> /
  
  10000 rows created.
  
  SQL> commit
    2  /
  
  Commit complete.
  
  SQL> select sextype, count(*) from tb_emp group by sextype
    2  /
  
  S   COUNT(*)
  - ----------
  M       5000
  F       5000
  
  SQL> exec dbms_stats.gather_table_stats(user,'TB_EMP',cascade=>true)
  
  PL/SQL procedure successfully completed.
  
  SQL> set autotrace traceonly explain
  SQL> select * from tb_emp where empid = 3000
    2  /
  
  Execution Plan
  ----------------------------------------------------------
     0      SELECT STATEMENT Optimizer=ALL_ROWS (Cost=3 Card=1 Bytes=5)
     1    0   INDEX (SKIP SCAN) OF 'EMP_SEXTYPE_EMP_IDX' (INDEX) (Cost=3 Card=1 Bytes=5)
  

• index skip scan

  Hi all
  excerpt from the page of doc guide 11-18 of rel2 11g performance tuning:

  Skip scanning is advantageous when there are few distinct
  values in the leading column of the composite index and many distinct values in the
  nonleading key of the index

  Anyone could explain it means by "nonleading key of the index?
  
  Best regards
  Val

  The key to an index is all the columns included in the index. The 'leader' or keys are the first column in the index. So, with an index on col1, col2, col3, you could make a request like:

  select * from table
  where col1 = value
  

  and have it use the index for a range scan. In this case, col1 is the main key. You could also do:

  select * from table
  where col1 = value and
        col2 = value
  

  In this case, col1 and col2 run keys. However, something like:

  select * from table
  where col2 = value and
        col3 = value
  

  does not use the main key to the index. According to a number of factors, Oracle may be able to skip scan this index to respond to your request.

  John

• I have a doubt about the file .folio and publications

  Hello, I m new here.

  I want to start working with DPS, but I have a doubt about which version to buy.

  At the moment I have one customer just wants to publish a magazine, but my intention is to have more customers and publish more magazines.

  If I buy the unique edition of DPS, I read that I can publish a single file .folio. What it means? Each folio file represents a publication?

  Please, I need help to understand this before you purchase the software.

  Thank you very much

  Paul

  Here's a quick blog I wrote to compare the simple edition and

  multifolio apps:

  http://boblevine.us/Digital-Publishing-Suite-101-single-Edition-vs-multi-Folio-apps/

  Bob

• Some doubts about the topology, interfaces and security modules

  Hello
  
  Below, some questions about the ODI:
  
  
  1. to use an LKM ODI always ask to use two different DATASERVERS (one for the SOURCE) and another to the TARGET?
  
  2. what would be the best way to create a new IKM with GROUP BY clauses?
  
  3. What is the required minimum PROFILE for developers users could import projects created in other ODI environments?
  
  4. If a particular WORK_REP is lost, it is possible that retrieve projects from version control information stored in the MASTER_REP?

  1.) Yes. LKM always loads data from one root to another.
  More than once I saw that even if there is a single physical server, several servers are configured in the topology Manager. This would lead to the use of a LKM because ODI consider 2 different servers.
  If the physical server is set only once, LKM won't be necessary.

  2.) IKM automatically adds a GROUP BY clause if it detects an aggregation function in the Interface implementation.

  3.) try to use the profile of the creator of NG.

  4.) this is not an easy task. But all the versioned objects are compressed and stored in a BLOB field in the master repository.
  You will need to know the names and versions you need to recover.
  SNP_VERSION and SNP_DATA have this information. Retrieves the field BLOB SNP_DATA and unpack using a zip utility. This will give you the XML property of the object that was transferred.
  Now, you can import this xml file and retrieve the object.

  You will need to loop through all the records in order of I_DATA, then extract to .xml file, and then import them to build the work rep.

• Some doubts about the navigation in unifying

  Hi all

  I had a few questions about unifying navigation.

  Is it possible to move the admin mode user mode access level?

  I mean, if a particular feature as Manager of the shell I can only access from admin mode is it possible to provide access even in user mode?

  If so, how?

  My 2nd question of doubt is, currently, we can access company BPs level "Journal of society" or "Resource Manager" under shell 'Company Workspace'.

  Is it possible to move the "journal of the society" or "Resource Manager" in the folder? If yes how?

  I tried in "navigation user mode" to move the company BPs level at shell of the House, but I can't do it.

  To answer your questions:

  (1) User-Mode browser can have the user feature included. You cannot change the view mode Admin or move functions admin for user mode.

  (2) you cannot move these on the Home tab.

• Doubts about the speed

  Hello gentlemen;

  I have a few questions, I would like to ask more experienced people here. I have a program running on a computer that has a processor i7 processor. In this computer that I have programmed in LabVIEW, meanwhile in another lab, we have another PC, a little older, a dual core 2.3 Ghz, in this pc, we perform a testing platform for a couple of modems, let us not get into the details.

  My problem is that I discovered recently that my program, I programmed in the computer, i7, much slower work in the other machine, the dual core, so the timings are all wrong and the program does not run correctly. For example, there is a table with 166 values, which, in the i7 machine are filled quickly, leaving almost without delay, however, the double machine heart, it takes a few milliseconds to fill about 20 values in the table, and because of the timing, it can fill more values and so the waveform that I use is all wrong. This, of course, live of the whole program and I can't use it as a test I need to integrate.

  I have create a .exe program in labview and try it in the different PC that's how I got to this question.

  Now, I want to know if there is actually a big problem due to the characteristics of the computer, the program is slow in one machine. I know that, to ensure the eficiently program, I need to use States, sub - vi, idea of producer-consumer machines and other things. However, I discovered this is not a problem of the speed generated by the program, because, if that were the case, the table would eventually fill it completely, however in slow computer, it is not filled more with 20 values.

  Else, helps to hide unnecessary variables in the front panel?, because the time beeing I have keep track of lots of variables in the program, so when I create the .exe I still see them runing to keep this follow-up. In the final version, that I won't need them so I'll delete some and hide front panel some. It helps that require less condition?

  I would like to read your comments on this topic, if you have any ideas in machines to States, sub - vi, etc., if there is a way to force the computer to use more resources in the Labview program, etc.
  I'm not add any VI because, in the current state, I know you will say, state machines, sub.vi and so on, and I think that the main problem is between the difference in computers, and I'm still working in the things of the State/sub-VI/etc

  Thank you once again, we just let this hollow.

  Kind regards

  IRAN.

  Get started with, using suitable as a machine for States stream you can ensure that your large table would be always filled completely before moving on, regardless of how long it takes. Believe it or not add that a delay to your curls will do more all the program run faster and smoother, because while loops are eager and can consume 100% of CPU time just a loop waiting for a button press, at the same time all other processes are fighting for time CPU.

• Doubt about the persistent object

  Hi friends,

  I've stored data object persistent after that some time, my Simulator has taken a lot of time to load the application so I run clear.bat do fast Simulator. But after I run clear.bat. The values of what I stored in the persistent object had disappeared. Someone at - he said, therefore, it is the persistent object data are parties to cause of the performer, the clear.bat or any other reason. pls clarify my doubt friends...

  Kind regards

  s.Kumaran.

  It is b'caz of clean.bat. Clean.bat will remove all applications and unnecessary files, etc...

• Doubts about the migration parallel to Lync 2013-&gt; Skype4B 2015 on VCS - C (not clustered)

  Hello everyone!

  As I saw on Cisco documents, applying "B2BUA/Microsoft Interoperability" on VCS can "communicate" with just an instance Microsoft Lync pool servers, but we need to migrate the Lync server on parallel to the servers of Skype, we need to have a few "maintenance window" to migrate all users!

  Can we keep 'UP' communication for VCS (lync and Skype) pool of two servers until the end of the migration? The lync Server legacy 2013 (shared resources) with VCS today can communicate with users (migrated) for 2015 of Skype with trunk Lync existing TLS today?

  I think we generate another certificate for TLS and affecting some Skype server on the option "host approved", that's okay, I forgot something? Or I have other ways to communicate two pools Microsoft server with a VCS - C with the application "B2BUA/Microsoft Interoperability?

  Thanks for help me!

  To see some possible examples of deployment options, refer to Appendix 3 of the infrastructure Microsoft (X8.8) Deployment Guide and totalled, suggest that you also look over the guide in full as it might answer some of your questions about what is supported.

• doubts about the css class...

  I tried to load a background image in the theme universal apex 5 in the login page.

  and I used the code found in the following link and got it works

  Apex 5.0: Theme Roller and background image

  But I doubt that can be very simple for the css professionals.

  .t-PageBody-.t-body connection

  {

  Background: URL("Sports.jpg") repeat top center white scroll;

  Color: #000000;

  do-family: Arial, Helvetica, Sans-serif;

  do-size: 12px;

  line-height: 17px;

  }

  .t - PageBody.t - body

  How do you know .t-PageBody - .t-body connection was the main class to change...

  Let me know if my interpretation is correct

  .t-PageBody - login is the main class

  and .t-Body is the upper class?

  
  

  pauljohny100 wrote:

  I tried to load a background image in the theme universal apex 5 in the login page.

  and I used the code found in the following link and got it works

  Apex 5.0: Theme Roller and background image

  But I doubt that can be very simple for the css professionals.

  .t-PageBody-.t-body connection

  {

  Background: URL("Sports.jpg") repeat top center white scroll;

  Color: #000000;

  do-family: Arial, Helvetica, Sans-serif;

  do-size: 12px;

  line-height: 17px;

  }

  .t - PageBody.t - body

  How know .t-PageBody-.t-body connection was the main class change...

  Let me know if my interpretation is correct

  .t-PageBody - login is the main class

  and .t-Body is the upper class?

  .t-PageBody--login .t-Bodyis a descendant selector. It matches any element with a class attribute that contains a t-Body value having an element ancestor with a class attribute that contains a t-PageBody--login value. There is no concept of 'main' class or 'slot' in CSS. The required selector is likely to have been determined on the supplement page using a web Inspector.

  It is advisable to take some tutorials to get at least a basic understanding of web technologies when you work with APEX.

• Doubt about the LDAP synchronization

  Hi all
  
  I have sync LDAP enabled on my server of IOM. I also installed OID connector. I installed it since I want a user to be able to see DIO user resource in service to him in the "resources" tab. Now, whenever I create a new user, the user is created successfully. Now I have an access policy that grants the user the user OID resource based on its role. Now, once the user is created, I see in the OID I use. Of course, it is placed in service in the cn = default user directory but I read here that it is configurable from the LDAP container rules xml file. Now this provisioning in OID arrives with LDAP synchronization, and so I do not see any resource under the tab "resources". Then I grants it the user the OID resource by attaching the role to him and now he gets put in service to the OID as well. Now I see that based on the pre fill out cards that I put in place, this user gets provisioned to the correct container in the OID. But the question is now I find myself with two users with the same name and details in the directory of the OID. I don't want that to happen. Is there some way I can cut the somehow OID LDAP synchronization over the create user operation? Commissioning product only when I apply the role and therefore in the correct container?
  
  Thank you
  $id

  This is where, with a solid knowledge of the IOM is required. Should be re-evaluated the connector. For example, if the user exists, you know that you can not use the default create the task from the user. You will need to put just a spot of AutoComplete, since you know that each user will exist. You must also remove all your form variables that are managed from the user profile of the IOM.

  I suggest the following:

  Change your form to include only the user ID, the common name and the OrclGUID and name of the organization. You can use a pre-fill adapter on all those who will come from the user profile, because they already exist. If you need to move them to a different OU, after execution of the AutoComplete that defines the status of provisioned, you could start an update task the organization name field, which then the user to the appropriate ORGANIZATIONAL unit.

  You really need to think about all the tasks, and what is involved and change the connector. When you implement two methods that accomplish the same thing, you need to remove a few pieces of one of them. If you need to look at all of the tasks that will be required and the actions which are carried out. Some of them will have to be autocomplété so you can always view the status of correct resource.

  -Kevin