Is this the right query to determine index fragmentation ?
SELECT AVG (tfrag)
FROM (SELECT /*+ ORDERED USE_NL(i) INDEX(i DR$TEXT_IDX$X) */
i.token_text,
(1
[code]...
The reason I am asking that before index rebuild it returned 86% but after rebuild (ALTER INDEX .. REBUILD) it returned
96% which does not make sense.
I did try ctx_report.index_stats but it takes more time to run.
How to find out who has dropped and when was the index created in database?
View 39 Replies View RelatedI am on Oracle 11.2.0.3 on Linux and have implemented Oracle Text.I created Oracle Text indexes with default setting. However in an oracle white paper I read that the default setting may not be right. Here is the excerpt from the white paper by Roger Ford:URL....(Part of this white paper below....)Index Memory.
As mentioned above, cached $I entries are flushed to disk each time the indexing memory is exhausted. The default index memory at installation is a mere 12MB, which is very low. Users can specify up to 50MB at index creation time, but this is still pretty low. This would be done by a CREATE INDEX statement something like: CREATE INDEX myindex ON mytable(mycol) INDEXTYPE IS ctxsys.context PARAMETERS ('index memory 50M'); Allow index memory settings above 50MB, the CTXSYS user must first increase the value of the MAX_INDEX_MEMORY parameter, like this: begin ctx_ adm. set_ parameter('max_index_memory', '500M'); end; The setting for index memory should never be so high as to cause paging, as this will have a serious effect on indexing speed. On smaller dedicated systems, it is sometimes advantageous to temporarily decrease the amount of memory consumed by the Oracle SGA (for example by decreasing DB_CACHE_SIZE and/or SHARED_POOL_SIZE) during the index creation process.
Once the index has been created, the SGA size can be increased again to improve query performance." (End here from the white paper excerpt)My question is:
1) To apply this procedure (ctx_adm.set_parameter) required me to login as CTXSYS user. Is that right? or can it be avoided and be done from the application schema? This user CTXSYS is locked by default and I had to unlock it. Is that ok to do in production?
2) What is the value that I should use for the max_index_memory should it be 500 mb - my SGA is 2 GB in Dev/ QA and 3GB in production. Also in the index creation what is the value I should set for index memory parameter - I had left that at default but how should I change now? Should it be 50MB as shown in example above?
3) The white paper also refer to rebuilding an index at some interval like once in a month: ALTER INDEX DR$index_name$X REBUILD ONLINE; We are on Oracle 11g and the white paper was written in 2003.
I am on 11.2.0.3 Enterprise Edition. We are using the new feature "Composite Domain Index" for a Domain index on a very large table (>250.000.000 rows). It really works with mixed queries. We added two number columns using FILTER BY.We have lots of DML on this table. Therefore, we are executing synchronize and optimize once the week. The synch behaves pretty normal. But "optimize_index" takes a very very long time to complete. I have switsched on 'logging' for the optimize process. The $I table takes some time but is finished normally. But the optimization of the $S table (that is the table created for the CDI feature) is running over 12 hours now - and far from being finished. From the logfile, I can see that it optimizes 1000 rows every 20 minutes. Here is the output of the logfile:
Oracle Text, 11.2.0.3.0
14:33:05 06/26/12 begin logging
14:33:05 06/26/12 event
14:33:05 06/26/12 process $N for optimize: SEQDEV.GEN_GES_DESCRIPTION_CTX_I
14:33:16 06/26/12
14:33:16 06/26/12
[code]....
I haven't found a recommendation from Oracle not to use "optimize_index" for Domain Indexes with CDI. But in my case, it would be much faster just to drop and recreate the Domain Index in question.
I have a question about database fragmentation.I know that fragmentation can reduce performance in query times. The blocks are distributed in many extents and scans process takes a long time. Oracle engine have to locate the address of the next extent..
I want to know if there is any system view in which you can check if your table or index has high fragmentation. If it's needed I will have to re-create, move or rebulid the table or index, but before I want to know if the degree of fragmentation is high.
Any useful script or query to do this, any interesting oracle system view?
I have a query which had a join:
a.c1=b.c1 and a.c2=@var
where @var is user supplied input at runtime...We had a index on a.c2 . The CBO would use this index to generate an opitimised query plan.We found some records from table "b" were dropping due to inner join. So we made a change in join. It'd be like
a.c1(+)=b.c1 and nvl(a.c2,@var)=@var
This query is no longer using the index, instead its doing a full table scan causing the query to slowdown.I have tried creating index on nvl(a.c2,'31-dec-9999')
But the CBO won't use it.Anyway to create index on this col so that full table scan can be avoided?
We have a table called address and having the address fields and city ,state etc. The table will store huge amount of data .We need to query on the table. I would like to know how can we fasten the query and improve the performance of the query by creating index on these columns...Query is given below . note that the nullable columns can have data
SELECT *
FROM address
WHERE address1 = 'a'
[Code]....
I've been successfully setting up text indexes on multiple columns on the same table (using MULTI_COLUMN_DATASTORE preferences), but now I have a situation with a one-to-many data collection table (with a FK to a lookup table), and I need to search columns across both of these tables. Sample code below, more of my chattering after the code block:
CREATE TABLE SUBMISSION
( SUBMISSION_ID NUMBER(10) NOT NULL,
SUBMISSION_NAME VARCHAR2(100) NOT NULL
);
CREATE TABLE ADVISOR_TYPE
[code]...
I've looked at DETAIL_DATASTORE and USER_DATASTORE, but the examples in Oracle Docs for DETAIL_DATASTORE leave me a little bit perplexed. It seems like this should be pretty straightforward. I'm trying to avoid creating new columns, and keeping the trigger adjustments to a minimum.
I have table of 60 gb(indexes 60gb ) and it is subject to fragmentation around 10gb .
I m going to remove fragmentation . As i know i have three options
1.expdp/impdp .
2.CTAS (create table ........as.......) with parallel option .
3.Moving table into another tablespace with parallel option .
I have 4 physical and 4 logical cores(total 8 cores) on server .
find out whether the rowmovement option in a partitioned table will cause fragmentation or not?
View 3 Replies View RelatedI am trying to get query output into textfile.The following procedure is working fine by creating directory as follows in sys user.The output is getting onto text file and it seen on server machine even.My question is I want to see the text file on local machine also instead of everytime connecting to server machine drive.How can I perform that?
create or replace directory INFO_DIR as 'D:Swapna';
grant read, write on directory INFO_DIR to fairpoint;
CREATE OR REPLACE PROCEDURE FAIRPOINT.utl_file_test_write_xls(filename in VARCHAR2 )
IS
output_fileutl_file.file_type;
v_pathVARCHAR2(500);
v_stringVARCHAR2(4000);
v_sqlstrVARCHAR2(2000);
BEGIN
BEGIN
[code]....
A query to find the table fragmentation.
View 1 Replies View RelatedI got the error ORA-01653: unable to extend table <OWNER.TABLE_NAME> by <BYTE> in tablespace <TABLESPACE> in my production database. But I could see 4GB of free space available in the tablespace. But this was resolved after increasing the Tablespace size by 1 more GB. So I wanted to know how I can I reclaim the 4GB space ?
While searching in internet I got few tips like there will be a fragmentation in the tablespace, the free space available in the tablespace may not be a continuous block. To avoid this we need to reorganize the tables using ALTER TABLE <TABLE_NAME> MOVE <TABLESPACE>; command.
But in my tablespace there are huge number of tables exists I cannot do reorganization of all the tables. So I need to know how to identify particularly what are the tables has more fragmentation? so that I can go for reorganizing those tables only.
My Database version in 9.2.0.7
Tablespaces are Locally Managed
To remove fragmentation which is the best method.
First one :
-----------------
1)Created a backup table from the Fragmented table (This table is a partitioned one).
2)Analyzed this table.
3)DROP the Fragmented table
4)Inserted the backuped up data from backup table to the Re-created table.
5)Analyze this table.
Second method
-------------------
1) Create a backup table newly, with PCTFREE =0
2) Inserted the data from Fragmented table ( This is a partitioned table) to backup table
3) Analyzed this table.
4) Truncate Fragmented table
4) Did Exchange partition of Fragmented table with Backup table.
The second method is not found to be removing the Fragmentation. Before the fragmentation was 28% after Second method the fragmentation is still the same. While the first method the fragmentation reduced to 16%.
Query used to find Fragmentation.
select table_name,
round((blocks*8),2) "table size kb",
round((num_rows*avg_row_len/1024),2) "actual data in table kb",
round((blocks*8),2)- round((num_rows*avg_row_len/1024),2) "wasted space kb",
[code]...
Query
SELECT case.case_objid FROM clrods.case@clrods.equant.com case, table_x_cwp_tickect_details_vw t WHERE CASE.case_condition_cd IN ('OPEN', 'OPEN-DISPATCH', 'OPEN-REJECT', 'OPEN-RETURNED') AND case.case_type_cd in ('CUSTOMER FAULT', 'CHRONIC','SCHEDULED ACTIVITY','PROBLEM') AND ROWNUM <= 500 AND case.case_objid = t.ticket_objid AND ( ( case.account_id = '672286' ) ) ORDER BY case.case_id DESC
From PROD
Plan
SELECT STATEMENT HINT: FIRST_ROWS Cost: 2,629 Bytes: 221,500 Cardinality: 500
37 SORT ORDER BY Cost: 2,629 Bytes: 221,500 Cardinality: 500
36 COUNT STOPKEY
[code]...
From DEV platform
Plan
SELECT STATEMENT HINT: FIRST_ROWS Cost: 591 Bytes: 61,134 Cardinality: 138
37 SORT ORDER BY Cost: 591 Bytes: 61,134 Cardinality: 138
36 COUNT STOPKEY
[code]...
1. Index is rebuild
2. stats are up to date
3. Redef on table is done.
Does "Update on a Partitioned Column" cause fragmentation ?
See example below :
Suppose I have a table as below that has approx 3 million rows and growing :
1) Table ABC :
file_id number
status_flag varchar2(1)
file_Content clob
date_created date
2) This table is list partitioned on Column "status_flag".
Column "status_flag" can take 3 values "A" or "B" or "C"
3) A file_id can transition from 1 "Status_flag" to another. [ A--> B , C--> B, B-->C, A --> C, etc ]
This means its possible to UPDATE the "status_flag " - the partitioned column.
Question :
-------------
1) Would the movement of rows from 1 partition to another cause fragmentation ?
2) Or Instead, should this be achieved by maintaining 3 tables - 1 each for every "status_Flag" as Table_A, Table_B, Table_C
This would mean that, if file_id 1, changes "status_flag" from 'A' to 'B' :
-- The corresponding row from Table_A will be created in Table_B
--- The same will be deleted from Table_A
This would still cause fragmentation ... with the overhead of Inserting a CLOB column from 1 table to another.
3) How to determine how much percent of the table is fragmented ?
i have deleted 20 lak rows from a table which has 30 lak rows,
and i wanted to release the fragmented space, what is the procedure other than exp/imp or alter table move
and also the recommended way to do this prod env... (coalesce /alter move etc.. )
db version is 11.2
Oracle DB version : 10.2.0.5.0
OS version HP-UX B.11.31 U ia64
DB size : 2TB
We have the above configuration for one of our oracle database. One of our DBA acts like he is only the person on this earth who is managing the process of fragmentation removal from the tablespaces in order to improve the performance and wastage of the space. He performs that task at weekends and takes one-off day extra. I am not sure how the fragmentation removal improves the performance and deallocates the space.
Is it compulsory to perform the rebuild process weekly in order to remove fragmented space from tablespaces? Do we have any other method to automatically re-organize objects occupying waste space?
Why the reuild of indexes using separate tablespace improves performance? is there any specifi reason for it?
oracle: 10.2.0.5.7...I can get this to work, but not the way the docs seem to say. I am wondering if I am reading the docs wrong or missing something.
The docs seem to say to get a query to run in parallel using an index you use the PARALLEL_INDEX hint. This doesn't seem to work for me. I have to do one of the following
1. change the parallel degree with an alter index, then use the PARALLEL hint (parallel index hint does nothing in this case)
2. use both the parallel_index and parallel hint
i am binding a string to a CONTAINS search (oracle text) and its throwing an error because of characters within the string.
this causes the error.
Quote:
(A. A.)
if i take out ( and ) it works
Quote:
A. A.
i thought binding took care of these issues as well as sql injection?
example:
SELECT
score(1) the_score,
id
FROM
t_table
WHERE
contains(text_column, :BINDVAR1, 1) > 0
how can i get around this and other character errors on the fly?
I want to do horizontal fragmentation of a table say employee. But fragmentation is often related to distributed databases. So i want to ask how can i do this on my single home computer? list out the steps that should be performed. I saw the concept of link but really failed to understand that.
View 14 Replies View RelatedI have tried below steps for removing the table fregmentation but for some table i am not getting good result here.
1. It will collect the data which are having more than 100MB fragmentation.
select owner,table_name,blocks,num_rows,avg_row_len,round(((blocks*8/1024)),2)||'MB' "TOTAL_SIZE", round((num_rows*avg_row_len
/1024/1024),2)||'Mb' "ACTUAL_SIZE", round(((blocks*8/1024)-(num_rows*avg_row_len/1024/1024)),2) ||'MB' "FRAGMENTED_SPACE" from
dba_tables where owner in('a','b','c','d') and round(((blocks*8/1024)-(num_rows*avg_row_len/1024/1024)),2)
> 100 order by 8 desc;
2. then move the object(table) to the same tablespace.
alter table abc move;
alter table bcd move;
alter table efg move;
3. also rebuild the dependent objects.
alter index abc_PK rebuild online;
4. Then analyze the table which are having more than 100MB of fragmentation.
exec dbms_stats.gather_table_stats('a','abc');
exec dbms_stats.gather_table_stats('b','bcd');
exec dbms_stats.gather_table_stats('c','cdf');
after that when check the table fragmentation, i am getting the same result, which i have collected from the 1st query.
I have already created large no of indexes on my Database without specifying specific tablespace, now I would like to move all the created indexes into particular tablespace.
View 3 Replies View RelatedI have the below query for which ename column has an index. As of my knowledge below queries 1st and 2st will not use index. Hence i used the 3rd statement and that too its not using the index. Finally i used the 4th query, but even the 4th query is not using the index. Then how do i make this query to use my index??? Do i need to create a function based index for this?
1. select * from emp where ename !='BH' ;
2. select * from emp where ename <> 'BH';
3. select * from emp where ename not in ('BH');
4. select * from emp where ename < 'BH' or ename > 'BH';
Suppose i have two columns ID and Status (or any number of columns ) belongs to table customer. Now I want to create below index
Ex. create index test1 on customer (ID , Status )
But before creating this index i want to check that whether there is already index on these 2 columns ? May be by other name ?
I want to execute a query which automatically saves the result of a set of queries in a text file and have to send that as an attachment thru a mail (using UTL_MAIL or UTL_SMTP) thru a stored procedure...saving the result in a text file in Toad.
View 2 Replies View RelatedI'm running this query on sql developer trying to export large file but its not executing.
set head off
spool c:myoracle.txt
select txt_name_insurer||'~'||txt_policy_number from Table_Name where rownum<'10';
spool off
set head on
Error:- line 1: SQLPLUS Command Skipped: set head on
I am using dbms_sql for creation and execution of dynamic query. But after execution,the results returned are not correct. Just wanted to know is there some way by which I can find the final text of dynamic query created by dbms_sql?
View 14 Replies View RelatedI would like to store my sql query output into text file.Like for example:
select name from emp where emp_id=101;
Here output should be in text file as
swapna.
I dont want to use spool statement here,since If I use it,spool statement will also be printed in text file which is not my requirement.I just want to take only output.
I have a SQL query where I am making UNION of two select statements. The table that I am joining in each select statement have indexes defined for those tables.
Now the UNION of the two select statements again in enclosed in an inline view , from which I fetching my final field values.
The select statements inside the inline view returns huge number of row (like 50 million rows).
The whole query fails with time out.
How can I optimize this query further?
Is there a way to pass Oracle Hints so that Oracle uses indexes?