Oracle index on the specified columns

Similar Questions

• Index on the date column

  Hello
  
  I have a behavior when running a table with an indexed column date that seems a bit away from me.
  
  I have a table with many columns and rows 4.8 million (Oracle 11 g 2). One of his columns is of data type Date. This column is indexed using a b-three index.
  
  Consider the select statement. It returns only 32 thousand rows (less than 1% of the number of rows in the table). Oracle did a full scan to run the query.
  
  Field2 can be any column of the table that is not part of the index (for example, a column which is varchar2 (14)).
  
  As the used filter has a high selectivity, I expect Oracle to use the index on the date_field when executing the query. Have no idea about it? Is there a rule on the date columns indexing?
  
  Select Field2
  TABLE
  WHERE date_field > = TO_DATE('13/09/2010','DD/MM/YYYY')
  and date_field < TO_DATE('14/09/2010','DD/MM/YYYY')

  user492400 wrote:
  The clustering_factor is not too high?

  OBJECT_TYPE-> INDEX
  BLEVEL-> 2
  LEAF_BLOCKS-> 14796
  DISTINCT_KEYS-> 3249780
  AVG_LEAF_BLOCKS_PER_KEY-> 1
  AVG_DATA_BLOCKS_PER_KEY-> 1
  CLUSTERING_FACTOR-> 3620372
  NUM_ROWS-> 4823298

  If you look at your plan, it has a cost of 11156.

  The CBO estimated 29446 lines will be returned. It's a selectivity of 29446/4823298, which represents 0.61%.

  Therefore, the cost of using the index is approximately:

  2 (blevel) + 0.61% of the 14796 (pads of sheets) + 0.61% 3620372 (clustering factor) which is about 22195 (assuming that CBO based default settings).

  22195 is superior (so much) than 11156 so Full Table Scan WINS.

  See you soon

  Richard Foote
  http://richardfoote.WordPress.com/

• Creating indexes in the XMLType column

  Hello
  
  I have the following for XML document stored as an XMLType column.
  
  < ocaStatus xmlns = "http://xmlbeans.apache.org/ocastatus" > < status > < > 934 statusCode < / statusCode > < statusDate > Wed Apr 07 16:05:53 GMT + 05:30 2010 < / statusDate > < userId > u0121845 < / userId > < comment > sent to FLC < / comment > < / status > < status > < statusCode > 934 < / statusCode > < statusDate > Wed Apr 07 15:58:25 GMT + 05:30 2010 < / statusDate > < userId > u0121845 < / username > < Comment > sent to FLC < / comment > < / status > < status > < statusCode > 934 < / statusCode > < statusDate > Wed Apr 07 15:54:02 GMT + 05:30 2010 < / statusDate > < userId u0121845 > < / userId > < comment > sent to FLC < / comment > < / status > < status > < statusCode > 750 < / statusCode > < statusDate > 2010 - 03 - 31 12:39:41.580 GMT + 05:30 < / statusDate > < u0121845 userId > < / userId > < comment > metadata of the Document is correct. < / comment > < / status > < status > < statusCode > 934 < / statusCode > < statusDate > 2010 - 03 - 31 12:39:41.580 GMT + 05:30 < / statusDate > < userId > u0121845 < / userId > < comment > sent to FLC < / comment > < / status > < status > < statusCode > 932 < / statusCode > < statusDate > 2010 - 03 - 31 12:39:41.580 GMT + 05:30 < / statusDate > < userId > u0121845 < / username > < comment > loaded Novus < /. comment > < / status > < status > < > 700 statusCode < / statusCode > < statusDate > 2010 - 03 - 31 12:39:41.580 GMT + 05:30 < / statusDate > < userId u0121845 > < / userId > < comment > Document is deleted from the OCA. < / comment > < / status > < / ocaStatus >
  
  I created as a result of the clues in the XML
  CREATING INDEX 'OCA_DEV '. "' OCA_STATUS_CODE_INDEX ' ON 'OCA_DEV '. "DOCUMENT_STATUS_XML"(EXTRACTVALUE('/ocaStatus/status/statusCode'));
  CREATING INDEX 'OCA_DEV '. "' OCA_STATUS_DATE_INDEX ' ON 'OCA_DEV '. "DOCUMENT_STATUS_XML"(EXTRACTVALUE('/ocaStatus/status/statusDate'));
  
  However, the problem is that I will be having several status within each XML that violates the indexing.
  Is there a way I can still create indexes for multiple State values in each XML file?
  
  Thanks in advance.

  Hello

  Take a look at the manual xdb (which version do you use?), for the 10.2 version, see: http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14259/xdb04cre.htm#sthref596
  It describes how you can index an XMLTYPE. Because you describe how you use, take a look at your needs.

  In 11G, you have the XMLINDEX to xmltypes indexing, you will find information here: http://download.oracle.com/docs/cd/E11882_01/appdev.112/e10492/xdb_indexing.htm#CHDFCGGI

  Herald tiomela
  Superconsult.nl

• How to get the index of the list column Mult box

  Hi all

  I need little help. Please help me.

  Is there is no property to dynamically change the index position of line "Multi column list box"?

  I want to change the index location when running as below.

  

  He called the top left cell Visible. There is no as many properties.

• Creation of several indexes of the columns of same

  Oradocs a little wave, at least my current source.

  When I create 2 indices of different types, example a bitmap another b-tree, on the same order of column, can both be running at the same time or if one of them must be invisible?

  He can't do it on my own, I have standard edition that does not support bitmap indexes

  Here:

  CREATE INDEX fun1 on employees (last_name);

  create fun2 index bitmap on employees (last_name);

  Thank you

  Oradocs a little wave, at least my current source.

  Docs? I don't see a link to any docs. We cannot comment on something that we cannot see. Post links to "Oradocs" you are talking about.

  When I create 2 indices of different types, a bitmap example another tree-b,.
  on the same column order, both can be operational in even
  time, or if one of them must be invisible?

  One of them may be visible. And several index on the same columns apply only to the 12 c.

  The Blog of Tom Kyte: 12 c - more than one index column even...

• How to create indexes on the column xmtype

  Hello
  
  I have a table as follows
  
  CREATE TABLE T_TEST_XML (ID_PROCESSUS NUMBER, TXT_XML XMLTYPE);
  
  
  I query the table above very frequently with the query
  
  SELECT * FROM TXS T_TEST_XML WHERE EXISTSNODE (TXS. TXT_XML, '/ order [status = "PEN"]') = 1
  
  
  How to create function function index on the TXT_XML column for the xpath expression/order [status = "PEN"]' to improve the query performance?
  
  Thank you

  In fact if you are limited to the use of older software

  1 consider to define an XML schema and store XML using storage relational object.

  or

  2. If you need to store XML as CLOB to create the index on extractValue(), rather than existsNode() and provide the underlying value at the SQL level rather than the XPATH level.

  SQL> DROP TABLE T_TEST_XML
    2  /
  
  Table dropped.
  
  SQL> CREATE TABLE T_TEST_XML (PROCESS_ID NUMBER, TXT_XML XMLTYPE)
    2  /
  
  Table created.
  
  SQL> create INDEX T_TEXT_XML_IDX on T_TEST_XML( extractValue(TXT_XML,'/order/status'))
    2  /
  
  Index created.
  
  SQL> set autotrace on explain
  SQL> --
  SQL> SELECT *
    2    FROM T_TEST_XML TXS
    3   WHERE ExistsNode(TXT_XML,'/order[status="PEN"]') = 1
    4  /
  
  no rows selected
  
  Execution Plan
  ----------------------------------------------------------
  Plan hash value: 3001212210
  
  ---------------------------------------------------------------------------------
  | Id  | Operation          | Name       | Rows  | Bytes | Cost (%CPU)| Time     |
  ---------------------------------------------------------------------------------
  |   0 | SELECT STATEMENT   |            |     1 |  2017 |    31   (0)| 00:00:01 |
  |   1 |  NESTED LOOPS SEMI |            |     1 |  2017 |    31   (0)| 00:00:01 |
  |   2 |   TABLE ACCESS FULL| T_TEST_XML |     1 |  2015 |     2   (0)| 00:00:01 |
  |*  3 |   XPATH EVALUATION |            |       |       |            |          |
  ---------------------------------------------------------------------------------
  
  Predicate Information (identified by operation id):
  ---------------------------------------------------
  
     3 - filter("P"."C_01$"='PEN')
  
  Note
  -----
     - dynamic sampling used for this statement (level=2)
  
  SQL> SELECT *
    2    FROM T_TEST_XML TXS
    3   WHERE extractValue(TXT_XML,'/order/status') = 'PEN'
    4  /
  
  no rows selected
  
  Execution Plan
  ----------------------------------------------------------
  Plan hash value: 1430727070
  
  ----------------------------------------------------------------------------------------------
  | Id  | Operation                   | Name           | Rows  | Bytes | Cost (%CPU)| Time     |
  ----------------------------------------------------------------------------------------------
  |   0 | SELECT STATEMENT            |                |     1 |  2015 |     1   (0)| 00:00:01 |
  |   1 |  TABLE ACCESS BY INDEX ROWID| T_TEST_XML     |     1 |  2015 |     1   (0)| 00:00:01 |
  |*  2 |   INDEX RANGE SCAN          | T_TEXT_XML_IDX |     1 |       |     1   (0)| 00:00:01 |
  ----------------------------------------------------------------------------------------------
  
  Predicate Information (identified by operation id):
  ---------------------------------------------------
  
     2 - access(EXTRACTVALUE(SYS_MAKEXML(0,"SYS_NC00003$"),'/order/status',null,0,0,5242
                93,133120)='PEN')
  
  Note
  -----
     - dynamic sampling used for this statement (level=2)
  
  SQL>
  SQL>
  SQL>
  SQL>
  SQL>
  SQL>
  

  This allows the index press questioning on any status value, rather than just the PEN

• How Index on a CLOB column?

  I have a need index on a CLOB column. The first attempts to index will result in ORA-02373.
  In research, I was able to find one that a LOB column could be moved to a different tablespace then indexed.
  
  So I intend to use these statements (see below), to create a text index on column CLOB STATEMENT_TEXT.
  Questions: What storage should be used for the CLOB column?
  What type of index is required to create a text index on the CLOB column?
  
  ALTER TABLE ANY_STATEMENT MOVE
  TABLESPACE INFOWH2 STORAGE (INITIAL 4096K)
  LOB (STATEMENT_TEXT) STORE lobsegment
  (TABLESPACE INFOWH2 STORAGE (INITIAL 4096K));
  
  Then:
  CREATE INDEXES IDXANYSTMTTEXTBINARY
  ON LOB (STATEMENT_TEXT)
  INDEXTYPE IS CTXSYS. CONTEXT;
  
  
  Here is the table in part:
  CREATE TABLE ANY_STATEMENT
  (
  ANY_STATEMENT_ID TANK (18 BYTES) NOT NULL,
  CODE VARCHAR2 (4 BYTE),
  STATEMENT_TYPE_ID_FK TANK (18 BYTES) NOT NULL,
  USER DEFAULT UPDATED_BY VARCHAR2 (50 BYTES)
  LAST_DATE_UPDATED DATE DEFAULT SYSDATE,
  DESTINATION_ID_FK TANK (18 BYTES),
  LANGUAGE_ID_FK TANK (18 BYTES) NOT NULL,
  DATE OF SUPERCEDED_DATE,
  NUMBER OF FORMULA_REFERENCE
  FORMULA_SERIAL VARCHAR2 (15 BYTE),
  TANK (18 BYTES) BY DEFAULT USER CREATED_BY_ID_FK NOT NULL,
  DATE_CREATED DATE DEFAULT SYSDATE NOT NULL,.
  ON_HOLD CHAR (1 BYTE),
  NUMBER OF TEMP_REFERENCE_NUMBER
  APPLICATION_NOTES VARCHAR2 (2048 BYTE),
  HOLD_REASON VARCHAR2 (1024 BYTE),
  STATEMENT_TEXT CLOB,
  REASON CLOB
  )
  TABLESPACE INFOWH
  PCTUSED 0
  PCTFREE 10
  INITRANS 1
  MAXTRANS 255
  STORAGE)
  ORIGINAL 112K
  MINEXTENTS 1
  MAXEXTENTS UNLIMITED
  PCTINCREASE 0
  DEFAULT USER_TABLES
  )
  NOCOMPRESS
  LOB (STATEMENT_TEXT) STORE AS
  (TABLESPACE INFOWH
  ALLOW ONLINE STORAGE
  8192 CHUNK
  PCTVERSION 0
  NOCACHE
  STORAGE)
  64K INITIALS
  MINEXTENTS 1
  MAXEXTENTS UNLIMITED
  PCTINCREASE 0
  DEFAULT USER_TABLES
  )
  )
  LOB (REASON) STORE AS
  (TABLESPACE INFOWH
  ALLOW ONLINE STORAGE
  8192 CHUNK
  PCTVERSION 0
  NOCACHE
  STORAGE)
  64K INITIALS
  MINEXTENTS 1
  MAXEXTENTS UNLIMITED
  PCTINCREASE 0
  DEFAULT USER_TABLES
  )
  )
  NOCACHE
  NOPARALLEL
  MONITORING;

  See if this thread is useful.

  http://www.orafaq.com/Forum/t/8494/0/

• create indexes on the upper part of the column - reminders function is not deterministic

  Hi all

  I'm having a problem on a database. When you create an index on an existing table on the upper part of a column, Oracle triggers an ORA-30553. I've done this 40 index other databases, with the same and different versions, without problem. When you create the index on a copy of the table, it is created with success...

  Here is the code:

  SQL > select * from v version $;

  BANNER

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

  Oracle Database 11 g Release 11.2.0.3.0 - 64 bit Production

  PL/SQL Release 11.2.0.3.0 - Production

  CORE Production 11.2.0.3.0

  AMT for 64-bit Windows: Version 11.2.0.3.0 - Production

  NLSRTL Version 11.2.0.3.0 - Production

  SQL > CREATE INDEX IDX_SRE_E_MAIL_UPPER on fsynrelatie (upper (sre_e_mail)) tablespace idx;

  CREATE the INDEX IDX_SRE_E_MAIL_UPPER on idx tablespace fsynrelatie (upper (sre_e_mail))

  *

  ERROR on line 1:

  ORA-30553: the function is not deterministic

  SQL > create table fsynrelatie2 in select * from fsynrelatie;

  Table created.

  SQL > CREATE INDEX IDX_SRE_E_MAIL_UPPER on fsynrelatie2 (upper (sre_e_mail)) tablespace idx;

  The index is created.

  SQL > drop table fsynrelatie2;

  Deleted table.

  SQL > show parameter query_rewrite_enabled

  VALUE OF TYPE NAME

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

  query_rewrite_enabled string TRUE

  Hi all

  Thank you for the answers. I found the problem:

  On the table, there are 54 index:

  Select index_type, uniqueness, count (*) from user_indexes where table_name = 'FSYNRELATIE '.

  Index_type group, uniqueness

  INDEX_TYPE	SINGLE CHARACTER	COUNT (*)
  FIELD	ARE NOT UNIQUE	1
  BASED ON A NORMAL FUNCTION	ARE NOT UNIQUE	4
  NORMAL	UNIQUE	3
  NORMAL	ARE NOT UNIQUE	46

  3 unique indexes are the primary key and 2 another witch number field contains unique identifiers for rows in other systems. The domain index is an index of Oracle text on a couple of fields. There are 3 indices of function based on a high on a field and 1 on an individual function. This last clue has caused the problem. Apparently, on the creation, this function is deterministic, but when rolling a new version of the software. It became a non-deterministic function. When I delete the index, my original index on upper (sre_e_mail) has been created successfully! Now, I did the deterministic function again and could recreate the function without problem.

  Thanks for your comments!

• An update on an index column with the same value generates an index to the top

  An update on an index column with the same value generates an update of the index?
  
  
  Thank you

  In addition to my previous answer, see also

  http://orainternals.WordPress.com/2010/11/04/does-an-update-statement-modify-the-row-if-the-update-modifies-the-column-to-same-value/

  Riyaj Shamsudeen has this to say:
  "+ We have an index on this column v1 and we update this column indexed too." Oracle was updating the indexed column? N ° if the values match the level of the indexed column, then the code of RDBMS isn't up-to-date index, a feature for optimization again. Only the row of table is updated, and the index is not updated. + "

  Hemant K Collette

• index on the column of low cardinality

  Hello
  Standard edition Oracle 10.2
  
  I have a 'status' column in my table. table contains about 100000 records.
  The possible values of status will be 1 or 2 (digital). This column will be 5 to 10 percent of the population, and the rest is null.
  
  Because it is seems that bitmap index is candidate for low cardinality column, but this picture has high of DML operations. SO by web research I learned about this bitmap causes problems of blocking on high DML operations.
  
  So I think that B-tree is only option left. Can you suggest a good index to improve performance on such a column?

  You don't need an index based on a function, do you think?

  You have a STATUS column where a small percentage of values is not null.

  To effectively access these lines whose STATUS is non-zero, simply create an index on the column State.

  This should be plenty effective.

  The effectiveness of this index (or the fbi if she was forced) is based on the fact that an index b-tree contains entry when the value is null (or all of the values in the case of a composite).

  There are those that 100000 is small and 5-10% is not particularly selective and you tell the width of the table, etc., so, even with the index here, it might not if used - i.e. depending on the circumstances it might be more efficient to do a FTS.

  It depends on what you want to do.

  See:
  http://asktom.Oracle.com/pls/asktom/f?p=100:11:0:P11_QUESTION_ID:4433887271030
  http://richardfoote.WordPress.com/2008/05/12/index-scan-or-full-table-scan-the-magic-number-magic-dance/

  Published by: Dom Brooks on February 10, 2011 12:58

• index on the column using custom function

  Can we create index on the column using custom function?

  http://www.dbasupport.com/Oracle/ora8/FBI.shtml

  Kind regards
  Kaila Mahesh

• The Oracle index

  Hi all
  I have 3 indexes on a table. The first clue is a combination of 8 columns, 2nd is a combination of 3 columns and the 3rd is a combination of two columns.
  
  I want to know is if I can write a query to join of two tables do I need to use all of the columns in where clause indexed to make it faster. Can I use either the column indexed to joints such as indexed scan happens.
  
  I also saw that oracle does not use the index that I defined in some places. Anyone know what is the circumstance where Oracle does not take account of the index.
  
  Thank you...

  user627047 wrote:
  Hi all
  I have 3 indexes on a table. The first clue is a combination of 8 columns, 2nd is a combination of 3 columns and the 3rd is a combination of two columns.

  I want to know is if I can write a query to join of two tables do I need to use all of the columns in where clause indexed to make it faster. Can I use either the column indexed to joints such as indexed scan happens.

  Your join must be written to meet the business logic of the application.

  I also saw that oracle does not use the index that I defined in some places. Anyone know what is the circumstance where Oracle does not take account of the index.

  Oracle ignores the index when the query optimizer determines that it is more expensive to use the index, or the index cannot be used. Is an example of the first case, if it determines that you will be during extraction, so many lines that it makes more sense to just do a FTS that incur additional IO tha of thing looking up in the index. An example of the second is the place where you can reference a column in your WHERE clause indexed, but apply you a function:

  SELECT *
  FROM mytable
  WHERE UPPER(indexed_col) = 'SOMEVALUE'
  

  In the snippet above, even the optimizer must determine I'm alone during extraction 1 row of 1 million, the UPPER() function will prevent the use of the index.

  Thank you...

• Index on the seeding Table Oracle Applications

  Hi all
  
  Can I create an index on a column to the table of the seeds of the oracle applications. If so, then, what are the implications? If not, what are the reasons... Can anyone give some input on this...
  
  Why I need this...
  
  I have a validation on the column 'JOURNAL_COMMENT' in Table 'IC_JRNL_MST' in my custom Interface program. It takes 2.5 minutes to complete the validation of a record. I created the index on this column in the process of development and validation time is reduced to less than a second. So, I need to create this index on an instance of production to reduce the time of validation.
  
  can I do it? (create the index on the production instance) forgot to mention... I can't ignore that particular column validation...
  
  Thanks in advance...
  Melanie

  You can certainly create indexes custom table seeded so this improvement in performance has to offer. I did it several times.
  As you know, a new index is provided with a cost (storage and maintenance), but it will be significantly smaller than your gains.
  A new index will not harm any validations / business logic.
  Just keep in mind that if you or a patch happens to drop and re-create the table, you must remember to rebuild the index.
  Hope that answers your question

  Sandeep Gandhi
  Independent consultant
  513-325-9026.

• MapViewer and index of the oracle

  Hi all
  The Oracle index can take over all the mapviewer API?. According to Oracle spatial UG (Appendix B), the Oracle index supports SDO_GEOM. SDO_BUFFER, SDO_GEOM. SDO_DISTANCE,
  SDO_GEOM. VALIDATE_GEOMETRY_WITH_CONTEXT, SDO_GEOM. VALIDATE_LAYER_WITH_CONTEXT. Other than the method, index of the Oracle can't stand not the other functions like SDO_GEOM SDO_GEOM. WITHIN_DISTANCE.
  API of the mapviewer as queryWithinRadius (...), identify (...) methods can use SDO_GEOM. Method WITHIN_DISTANCE internally. Is there a any restriction for the oracle mapviewer on index?
  
  Please specify.
  
  Sujnan

  Sujnan,
  MapViewer uses space as operators: sdo_within_distance, sdo_filter and sdo_nn and sdo_relate and not the
  Functions package SDO_GEOM.
  And all of the operators used by MapViewer are part of landmark (as long as you do not use the themes GeoRaster or network topology).

  Siva

• How it warns Oracle to use an index for the join of two tables...

  How to prevent the Oracle to use an index for the join of two tables to get a view online that is used in an update statement?
  
  O.K. I think I should explain what I mean:
  
  When you join two tables that have many entries sometimes there're better is not to use an index on the column that is used as a criterion to join.
  
  I have two tables: table A and table B.
  
  Table A has 4,000,000 entries and table B has 700,000 entries.
  
  I have a join of two tables with a numeric column as join criteria.
  
  There is an index on this column in A table.
  
  So I instead of
  

    where (A.col = B.col)

  I want to use
  

    where (A.col+0 = B.col)

  in order to avoid Oracle using the index.
  
  When I use the join in a select query, it works.
  
  But when I use the join as inline in an update statement I get the error ORA-01779.
  
  When I remove the '+ 0' the update statement works. (The column is unique in table B).
  
  Any ideas why this happens?
  
  Thank you very much in advance for any help.
  
  Hartmut cordially

  You plan to use a NO_INDEX hint as shown here: http://www.psoug.org/reference/hints.html