Foglight for Oracle - Bitmap Index

Similar Questions

• All parameter memory index for Oracle text indexes

  Hi Experts,

  I'm on Oracle 11.2.0.3 on Linux and have implemented Oracle Text. I'm not an expert in this area and need help on a question. I created the Oracle text index with the default setting. However, in a white paper of oracle, I read that the default setting is perhaps not good. Excerpt from the white paper by Roger Ford:

  URL:http://www.oracle.com/technetwork/database/enterprise-edition/index-maintenance-089308.html

  "(Part of this white paper below. )" ...)

  Index memory as mentioned above, $I entries cached emptied out on the disk each time the indexing memory is exhausted. The default index to installing memory is a simple 12MB, which is very low. At the time of creating indexes, users can specify up to 50 MB, but it is still quite low.                                   

  This would be by a CREATE INDEX, something like statement:

   CREATE INDEX myindex ON mytable(mycol) INDEXTYPE IS ctxsys.context PARAMETERS ('index memory 50M');  

  Allow index of the parameters of memory beyond 50 MB, the CTXSYS user must first of all increase the value of the MAX_INDEX_MEMORY parameter, like this:

   begin ctx_adm.set_parameter('max_index_memory', '500M'); end;  

  The parameter memory must never be high point causes paging, because this will have a serious effect on indexing speed. The smallest of dedicated systems, it is sometimes advantageous to temporarily reduce the amount of memory consumed by the Oracle SGA (for example by reducing DB_CACHE_SIZE and/or SHARED_POOL_SIZE) during the index creation process. Once the index has been created, the size of the SGA can be increased again to improve query performance. & quot;

  (End of the excerpt from the white paper)

  
  My question is:

  (1) to apply this procedure (ctx_adm.set_parameter) obliged me to log on as user CTXSYS. Is this fair? or can it be avoided and will be based on the application schema? The CTXSYS user is locked by default and I had to unlock it. Is this OK to do it in production?

  (2) what value I should use for the max_index_memory there are 500 MB - my SGA is 2 GB in Dev / QA and / 3 GB in the production. Also in the creation of the index which is the value should I set for the parameter memory index - I had left to default, but how do I change now? Should it be 50 MB as shown in the example above?

  (3) the white paper also refer to the reconstruction of an index to an interval like once a month: ALTER INDEX DR$ index_name$ X REBUILD online;

  -Is this good advice? I would like to ask the experts once before doing this.  We are on Oracle 11 g and the white paper was drafted in 2003.

  Basically, while I read the book, I'm still not clear on many aspects and need help to understand this.

  Thank you

  OrauserN

  Index entries are built in memory, and then flushed to disk, memory is exhausted. With a setting of high index memory will mean the index entries can be longer and less fragmented, which provides better performance of the query.  Conversely, a small memory parameter index will mean emptied the disk pieces are smaller, so queries (especially on common words) will have to do a lot more e/s to extract several pieces of index for the words.

• Foglight for Oracle - trend

  All,

  There is a simple feature oriented in Cacti was asked to implement in Foglight. Essentially the metrics about 15 than the big trend like boss out of Oracle 10 g.

  He sent me this link for example, any ideas on how I could pull this off in foglight?

  http://forums.cacti.NET/about25495.html

  It would be an excellent suggestion to display in the Tab Foglight ideas.

  I would certainly vote it upward, and I bet others would too!

  Kind regards

  Brian Wheeldonn

• Bitmap index frequently updated useful column or not?

  I have a table of transaction with the status column.

  Table contains millions of records.

  Status, column values can be hold, dealt with, consult, error, completed.

  Initially table column populate status pending and later value will be updated to processed or see even then will be updated to completed or error.

  Is it useful to have the index bitmap on this column we update frequently on the status value

  Is it useful to have the index bitmap on this column we update frequently on the status value

  No - your is NOT a valid use for a bitmap index case.

  There would be little or NO value with only one index of bitmap on the table, if the column has been updated frequently or not.

  The power of the bitmap index is stronger when MULTIPLE indexes are used in the same query to identify/filter data.

  See my answers in this thread

  https://forums.Oracle.com/forums/thread.jspa?MessageID=10217613�

  In this thread I provide more details and code examples and execution of plan that show you a more typical use of bitmap indexes and their power.

  Try this code example to get a better understanding of the proper use of the case for the bitmap index.

• When the CBO would not use bitmap indexes available?

  I have a large data warehouse table in a star schema classic, with an index number of bitmap for the dimension tables. When you run queries that contain parameters for multiple indexes, the CBO will only use generally one or rarely two bitmap index.

  It seems to me that if the indexes are valid, statistics, the values of the parameters are present, etc and the CBO uses a bitmap index in an AND condition, he would like to use all those she could.

  there all the parameters that affect or bitmap how indexes him CBO will use? I'm looking for some advice on what to look for or research.

  Database is 11.2.0.3 base with no patch.

  Thanks in advance,

  Sean

  rp0428 - who has been deliberate because my question is not "how to solve this problem", that's exactly what I pointed out in my post. Just trying to see if there are all the controls to weight the decision-making community organizations in this area.

  OK - then let me simply state it.

  No - there are NO these parameters. But most of the posters are not really looking for a simple yes/no answer even if of many word of questions like that.

  See my response as of March 18, 2012 19:21 in this thread: https://community.oracle.com/message/10219613?

  Here I provide a simple table with SIX bitmap index, a query that uses predicates that combine values since the execution plan and the six columns indicating the different INDEX of BITMAP UNIQUE BITMAP, BITMAP or operations and BITMAP CONVERSION to ROWID.

  I won't repeat everything here, but this example should show you that Oracle will limit itself the way you suggest.

• BTREE and Bitmap indexes

  How the Btree and Bitmap index works?

  Osama_mustafa wrote:
  If you google it you will find some topics/article talking about this.

  Refer to this:
  Index bitmap:
  http://www.DBA-Oracle.com/oracle_tips_bitmapped_indexes.htm

  BTREE index
  http://www.DBA-Oracle.com/t_garmany_easysql_btree_index.htm

  Better not to refer to one of these items, they contain too many errors.
  If textbooks are not good enough, then the best source of information indexing is Richard Foote's blog.

  (Or add "Richard Foote" for your research, you do it for the b-tree or bitmap index.

  Concerning
  Jonathan Lewis

• Oracle Text Index rebuilt manually or automatically by DEFAULT

  For the following statement:
  
  "The Oracle * text (officially called Oracle and Oracle Intermedia context) utility allows us to analyze through a column of large text and indexes on the words in the column."
  
  Unlike the ordinary tree or bitmap index, index of context, ctxcat and ctxrule Oracle may be * set isn't content update is changed.* like most of Oracle databases will use with standard relational tables ctxcat index, you must decide on a refresh interval.  Oracle provides the SYNC operator for this.  The default value is SY ^ NC = MANUAL and you must manually synchronize the index with CTX_DDL. SYNC_INDEX.
  
  SYNC (MANUAL |) EACH interval 'string ' | ON VALIDATION)]
  
  «As a result, Oracle Text indexes are only useful for removing full table scans when tables are read-only in large part and/or end users don't mind not having 100% search reminder»
  
  -My question: the statement above claims: "Oracle indexes context, ctxcat and ctxrule can be configured to not update the content is changed. '." " Then what is the default setting for updating the index, manual or automatic? For example:
  
  First of all, I created an index like this: create index users_address_idx on users (address) indextype is ctxsys.ctxcat;
  
  Then, I made a few changes on the table such that change the values of the column address for several lines.
  
  The Oracle system will rebuild the ctxcat index automatically?
  
  What does the ' default is SY ^ NC = MANUAL "as shown in the quote?
  
  
  Thank you for helping.
  
  Scott
  

  scottjhn wrote:
  This source: http://www.dba-oracle.com/oracle_tips_like_sql_index.htm States:

  All first upward, please do not use the Web sites which present only part of the information and instead to advertise their services.

  -My question: the statement above claims: "Oracle indexes context, ctxcat and ctxrule can be configured to not update the content is changed. '." " Then what is the default setting for updating the index, manual or automatic? For example:

  First of all, I created an index like this: create index users_address_idx on users (address) indextype is ctxsys.ctxcat;

  Then, I made a few changes on the table such that change the values of the column address for several lines.

  The Oracle system will rebuild the ctxcat index automatically?

  No, the deafult is SYNC = MANUAL
  http://docs.Oracle.com/CD/B28359_01/text.111/b28304/csql.htm#CIHGAAFI
  >

  What does the ' default is SY ^ NC = MANUAL "as shown in the quote?

  This means that the need for the Index to synchronize manually
  http://docs.Oracle.com/CD/B28359_01/text.111/b28304/cddlpkg.htm#i998469

• CBO: full instead of bitmap index use, why table scan?

  I have a query in which it is clearly benefitial to use the bitmap index, rather oracle goes for the full table scan. Could you please shed some light on this? Because even a hint does not help, I guess that something prevents oracle (11.1.0.7.0) to use it in a sort of range index scan pass.
  
  installation program:

  create table test_distance (
  x_display number,
  y_display number,
  x_rough number(5,2) as (trunc(x_display,2)),
  y_rough number(5,2) as (trunc(y_display,2)));
  
  insert into test_distance (x_display,y_display) 
  (select dbms_random.value(-180,180), dbms_random.value(-90,90) from dual connect by level < 200000);
  
  create bitmap index test_bm_xrough on test_distance(x_rough);
  create bitmap index test_bm_yrough on test_distance(y_rough);
  
  create or replace function  western_bbox_longitude(x binary_double, y binary_double, radius binary_double) return number
  is
  begin
    --simplified
   return x - 0.0001*radius;
  end;
  /
  
  exec dbms_stats.gather_table_stats(user,'TEST_DISTANCE',cascade=>true,estimate_percent=>100);

  several select statements:

  --remember x and y values and use them in the subsequent queries.
  select * from test_distance where rownum = 1;
  
  alter session set statistics_level = all;
  
  --no bind variable, no function call -> proper plan
  select * from test_distance where x_rough = 16.14 and y_rough = -35.53;
  select * from table(dbms_xplan.display_cursor(null,null,'ALLSTATS LAST'));
  
  --with bind variable, no function call -> still proper plan
  select * from test_distance where x_rough = :xin and y_rough = :yin;
  select * from table(dbms_xplan.display_cursor(null,null,'ALLSTATS LAST'));
  
  --using between, bind variable, no function call -> proper plan
  select * from test_distance where x_rough between :xin-0.01 and :xin and y_rough between :yin-0.01 and :yin;
  select * from table(dbms_xplan.display_cursor(null,null,'ALLSTATS LAST'));
  
  
  --full table scan, why?
  select td.*,
  trunc(western_bbox_longitude(:xin,:yin,:radius),2)
  from test_distance td 
  where x_rough = trunc(
  western_bbox_longitude(:xin,:yin,:radius),2);
  select * from table(dbms_xplan.display_cursor(null,null,'ALLSTATS LAST'));
  
  --forcing oracle to use the index results in bitmap index full instead of range scan, why?
  select /*+ index( td test_bm_xrough) */ td.*,
  trunc(western_bbox_longitude(:xin,:yin,:radius),2)
  from test_distance td 
  where x_rough = trunc(
  western_bbox_longitude(:xin,:yin,:radius),2);
  select * from table(dbms_xplan.display_cursor(null,null,'ALLSTATS LAST'));
  
  --guessing it might be related to the selectivity of the function doesn't change the plan either
  associate statistics with functions western_bbox_longitude default selectivity 0.001;

  Ah sorry, I somehow read the wrong line in your initial statement where it between the function has been used.

  Yes it is possible that the selectivity of the function plays a role here. More likely may be the order of execution for the undeterministic functions is then different for literals. However, you can try to work around this problem by using a few different approaches.

  encapsulate the function inside a double subseelct

  select /*+ index( td test_bm_xrough) */ td.*,
     (select trunc(western_bbox_longitude(:xin,:yin,:radius),2))
  from test_distance td
  where x_rough = (select trunc(western_bbox_longitude(:xin,:yin,:radius),2) from dual);
  

  This should allow to cache the result of the function to a certain extent. Otherwise, the result of the function may be recalculated for each row in the test_distance table.

  The same can be achieved with a WITH clause
  not tested

  with wboxlong as (select trunc(western_bbox_longitude(:xin,:yin,:radius),2) xrough from dual)
  select /*+ index( td test_bm_xrough) */ td.*,
     x.xrough
  from test_distance td
  join wboxlong x on td.x_rough = x.xrough
  

  Also note that your tip worked. Oracle uses the bitmap indexes to access the data. Index indicator indicates to the CBO to use this index if possible, but is not on the path. If you want a different plan, you can try to apply also the path combined with a suspicion as NO_INDEX_FFS (http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/sql_elements006.htm#SQLRF50413).

  Published by: Sven w. on January 3, 2011 18:57

• Local Bitmap Index confusion

  Hello
  I use Oracle 10.2.0.3.0 on Solaris 5.10.
  
  I have a range based to 60 partitions partition table. It is a fact table. I load the data for 60 days in this table. I created a partition for each day, and the partition key is the column date. I've created the table with the partition, but does not create the local bitmap index on the partition keys $vdate, because as far as I know oracle makes the local bitmap index unusable before insert you and then to rebuild it after the charge. Is this fair?
  
  So the best strategy is first load the data in the partition, and then create a local on this partition, is bitmap index - this exact?
  
  For example, in the future, some lines get inserted into an existing partition where the local bitmap index is present, then I should still once rebuild the index on that partition, as in the case of insertion Oracle would have it turned off?
  
  
  In this table, it has a vactivity column that is a foreign key to a dimension. Several queries use this column here where clause. I also want to create an index of bitmap on this column? On this not partitioned key column, the local bitmap index should be created. Is this fair?
  
  Please also suggest as which is faster, a local bitmap index rebuild after making it unusable, or the deletion and recreation it?
  
  Thank you and best regards

  If you insert only a few lines, you don't need to score the unusable bitmap index partition. The insert will not fail.

  However, if you perform a bulk insert several lines, it would be desirable mark it unusable and rebuild after insertion.

  You can certainly create an index on the column of the FK.

  Hemant K Collette

• Flow of business process for Oracle Cloud

  Hello

  Where can I find the business process / model (BPM) runs for Oracle Cloud (Financials, HCM, sales, Service, Taleo)?

  
  Something similar to the reference model to the Oracle BPA Suite retail (Business process architect) would be good, as long as it is relevant to Oracle Cloud.

  
  

  I'm looking for the level 0 (Oracle Cloud) and 1 (HCM, sales, Service, financial services, Taleo) process flow (level 2 and 3 in option).
  

  
  

  Thank you

  Franklin
  

  I found the information required in the assistance of merger:

  https://fusionhelp.Oracle.com/helpPortal/BPM/index.htm

• INI_TRANS for TABLE and INDEX

  Hello
  
  My version of DB is 10.2.0.3
  
  As default, the INI_TRANS of the tables is 1 and for the index is 2. For some reason I have to increase the INI_TRANS of a table at 5, then what value set for INI_TRANS of indexes on the table?
  
  I read somewhere that INI_TRANS of the index to be set twice from INI_TRANS. means of the table if table INI_TRANS is 5 then INI_TRANS of the index must be set to 10. Is this true? If Yes, then what is the logic behind this?
  
  
  
  Thank you
  Oratest
  
  Published by: oratest on February 4, 2013 15:26

  oratest wrote:

  My version of DB is 10.2.0.3

  As default, the INI_TRANS of the tables is 1 and for the index is 2. For some reason I have to increase the INI_TRANS of a table at 5, then what value set for INI_TRANS of indexes on the table?

  I read somewhere that INI_TRANS of the index to be set twice from INI_TRANS. means of the table if table INI_TRANS is 5 then INI_TRANS of the index must be set to 10. Is this true?

  N °
  There is no useful guidelines for a generic parameter. Consider the conflicting scenes:

  (a) five sessions insert five rows separated in a single table block - with 5 locations of ITL. There is an index on the table, but the five inserted rows just keep these different values that their index entries go to 5 different leaf blocks: the index didn't need initrans 5.

  (b) using the different sessions to insert a row in a table - the nature of the SAMS means that (on average) there are 5 rows of SAMS 80 inserted into 16 different blocks - the SAMS table must be 5. However, in this case the indexed column is generated by a sequence and all 80 index entries should be inserted in the same block of sheets, so you initrans 80 on the index. (Except Oracle will make sheets index block split to work around the problems of initrans was too small on the concurrent inserts.)

  You need to consider the nature of the index and model of changing data for each unique index separately - and then you could assign initrans on the index to do NO MORE THAN the initrans + 1 table because (a) who will lose not too much space (b) he is not likely to let the too great claim to happen (c) Oracle will extend dynamically LAUGHED in most cases (d) if it is bad for an index special you will notice it pretty quickly - and there will be other problems (buffer waits occupied) deal anyway on this index.

  Concerning
  Jonathan Lewis

• Oracle Text Index

  Hi all
  
  I have a question about the Oracle text Index:
  
  The used Oracle text index after entering data in the CLOB column or before? or anytime.
  
  
  CREATE the INDEX Ora_TXT_Index_ON_Test ON te1 (name) INDEXTYPE IS CTXSYS. CONTEXT;
  
  EXEC DBMS_STATS. GATHER_TABLE_STATS (waterfall of the USER 'TE1' = > TRUE);
  
  concerning

  Hello
  a text index is not used in the normal way. You must use a clause in your SQL statement that is looking for your text by using the keyword Index of contains. An Oracle text Index will be refreshd of way manual or if you specify validation to your index.

  Perhaps this links help
  http://Oracle-text-de.blogspot.co.at/2008/06/scoring-MIT-Oracle-text.html
  http://docs.Oracle.com/CD/B19306_01/text.102/b14218/cqoper.htm

  concerning
  Peter

• Model reusable SQL Oracle to create a DDL/DML Scripts for Oracle database

  Hello
  
  
  I have an obligation to set up a model of Oracle SQL to create the Scripts DDL/DML reusable for Oracle databases.
  Only the Oracle DBA will run scripts permissions is not a problem.
  
  The workflow for any DOF is as follows:-
  
  (1) new table
  
  a. check whether the table exists in the views system/admin.
  b. If the table exists then give message "Table exists".
  c. If the table does not exist then run DDL code
  
  (2) add the column
  
  a. check if the column exists for a given table of the system/admin views
  b. If the column exists in the specified table.
  B1. backup table.
  B2. ALTER table alter column
  B3. check data or execute convert dml sauvegardΘ to the new change script.
  c. If the column does not exist
  C1. backup table
  C2. ALTER table add column
  C3. Run dml to populate the column with the default value.
  
  The DML scripts are to populate the base tables with the data required for business operations.
  
  (3) addition of new line
  
  a. check if the line exists by comparing the old values of each column with the new values to be added for the new record.
  b. If there is, to give message line is
  c. If not exists, add the new record.
  
  (4) update existing record (we createtime columns in these tables as well as changes can be tracked)
  
  a. check if the row exists using the primary key.
  b. If there is.
  B1. off the record by using the "active" column of the table
  B2. Add new record with the necessary changes.
  c. If does not exist, add the new record with the necessary changes.
  
  Could you please help with some ideas that can get this done with precision?
  I tried several ways, but I am not able to set up something that meets all the requirements.
  
  Thank you

  If it helps at all. Sometimes we have a requirement for a DDL statement to be rerunable and her only error if something completely unexpected happens.

  It's a little monstrous, but basically, we wrap all DDL in a dynamic statement and capture errors that would indicate that the DDL script has already been run:

  Here's a bit of a model:

  declare
     w_ddl varchar2(32767);
  begin
     begin
        --
        dbms_output.put_line('Creating table TABLE_NAME');
        --
        w_ddl := 'CREATE TABLE MY_SCHEMA.TABLE_NAME
                  ( COLUMN_1     DATE          NOT NULL
                   ,COLUMN_2  VARCHAR2(10)  NOT NULL
                   ,COLUMN_3  DATE
                  )';
         --
        execute immediate w_ddl;
        --
        dbms_output.put_line('Successfully created table TABLE_NAME');
        --
     exception
        when others then
           if sqlcode = -955 then
              dbms_output.put_line('Table Already exists.');
           else
              dbms_output.put_line('creation of table TABLE_NAME failed:');
              dbms_output.put_line(sqlerrm);
              raise;
           end if;
     end;
  
    begin
        --
        dbms_output.put_line('Creating unique primary key constraint for TABLE_NAME');
        --
        w_ddl := 'ALTER TABLE MY_SCHEMA.TABLE_NAME ADD (
                 CONSTRAINT TABLE_NAME
                 PRIMARY KEY
                 (TABLE_NAME_ID) USING INDEX)';
         --
        execute immediate w_ddl;
        --
        dbms_output.put_line('Successfully created primary key on TABLE_NAME_ID');
        --
     exception
        when others then
           if sqlcode = -02264 then
              dbms_output.put_line('constraint already exists.');
           else
              dbms_output.put_line('creation of primary key failed:');
              dbms_output.put_line(sqlerrm);
              raise;
           end if;
     END;   
  
  <>
  

  It works well with our scripts to autmoated and help us when we iterate through development and back in if needed test environments.

  In this way, we can add the DDL statements to the deployment script and run the script again without error to set the database to the State required without having to run the newly created statement only.

  Sometimes this approach translates into a creation followed a statement alter table statement to add a column, but the end result of the script is always the same, and the deployment script can be controlled at source between iterations of development that is without having to restore the ddl changes to test the modified DDL script.

  hope that gives you some ideas.

• DM 3.1 how to create a Bitmap Index?

  How to create a bitmap with SQL Developer Data Modeler 3.1 index? In the relational model, the properties of the General table allows to enumerate the indexes of a table and to clarify some of their attributes as such as columns and uniqueness. In addition, the properties of the plain index allows more options to set the properties of the index. Unfortunately, I'm unable to find the right place to specify that an index is an index of bitmap.
  
  However, maker of data tend to support bitmap indexes because the generated DDL statements for a table with bitmap indices, which was initially imported into the data dictionary, have correct index bitmap creation instructions. However, when I compare all B tree index with bitmap index in Data Modeler I can't find an option that specifies the index type as bitmap. So, I would be very happy if someone could tell me how to create bitmap with Data Modeler 3.1 indices.
  
  Best regards
  
  Miikka

  Hey Miikka,

  physical model is the place where you can define the specifications of database objects created in the relational model. So you open the physical model and you can find the node index under the node for the related table - use dialog for index set to the index of the bitmap image.

  Philippe

• KPI for oracle databases

  Hello guys,.
  
  I'm working on a report to my management on the capacity planning of our databases (GR 11, 2 on Sparc 64). For me the ability to forecast, I need my current performance of the document. So I'm basically looking for key performance indicators against which the capacity planning could be made. Any one who worked on the same requirement please share your approach and if you can you please recommend a suitable tools.
  
  Kind regards
  
  BMP

  I'm working on a report to my management on the capacity planning of our databases (GR 11, 2 on Sparc 64). For me the ability to forecast, I need my current performance of the document. So I'm basically looking for key performance indicators against which the capacity planning could be made. Any one who worked on the same requirement please share your approach and if you can you please recommend a suitable tools.

  Please see these links/docs.

  Master Index user experience Insight (RUEI) [ID 1305008.1]
  Oracle Real user experience Insight - software and documentation download site [579348.1 ID]
  Activation of the lap times for Oracle user experience Insight (RUEI) with e-Business Suite [ID 811866.1]
  FAQ, tips and tricks for the user experience Insight User Interface [1305827.1 ID]

  http://bit.LY/ygyH70
  http://bit.LY/w3FJlV

  Thank you
  Hussein