Index creation on Blob column

I am new to InterMedia. I am trying to create an index on a blob column. I am getting a error -
Can you please suggest me the solution of this problem.
Thanks.......
The following statement(s) failed to execute successfully.
CREATE INDEX temp.ind1 ON temp.student(MOL) INDEXTYPE IS CTXSYS.CONTEXT PARAMETERS('')
ORA-29855: error occurered in the execution of ODCINDEXCREATE routine
ORA-20000: interMedia Text error:
DRG-50704: Net8 listener is not running or cannot start external procedures
ORA-28575: unable to open RPC connection to external procedure agent
ORA-06512: at "CTXSYS.DRUE", line 122
ORA-06512: at "CTXSYS.TEXTINDEXMETHODS", line 34
ORA-06512: at line 1
null

Listner problems probably. Please check the FAQ at http://technet.oracle.com/products/text/

Similar Messages

Problem with blob column index created using Oracle Text.

Hi,
I'm running Oracle Database 10g 10.2.0.1.0 standard edition one, on windows server 2003 R2 x64.
I have a table with a blob column which contains pdf document.
Then, I create an index using the following script so that I can do fulltext search using Oracle Text.
CREATE INDEX DMCS.T_DMCS_FILE_DF_FILE_IDX ON DMCS.T_DMCS_FILE
(DF_FILE)
INDEXTYPE IS CTXSYS.CONTEXT
PARAMETERS('DATASTORE CTXSYS.DEFAULT_DATASTORE');
However, the index is not searchable and I check the following tables created by database for my index and found them to be empty as well !!
DR$T_DMCS_FILE_DF_FILE_IDX$I
DR$T_DMCS_FILE_DF_FILE_IDX$K
DR$T_DMCS_FILE_DF_FILE_IDX$N
DR$T_DMCS_FILE_DF_FILE_IDX$R
I wonder what's wrong with it.
My user has been granted the ctx_app role and I have other tables that store plain text which I use Oracle Text are fine. I even output the blob column and save as pdf file and they are fine.
However the database seems like not indexing my blob column although the index can be created without error.
Please advise.
Really appreciate anyone who can help.
Thank you.

The situation is I have already loaded a few pdf document into the table's blob column.
After I create the Oracle text index on this blob column, I find the system generated index tables listed in my earlier posting are empty, except for the 4th table.
Normally we'll see words inside the table where those are the words indexed by oracle text on my document.
As a result, no matter how i search for the index using select statement with contains operator, it will not give me any result.
I feel weird why the blob is not indexed. The content of the blob are actually valid because I tested this by export the content back to pdf and I can still view and search within the pdf.
Regards,
Jap.

Problem full-text in blob column index created using Oracle Text

Hi,
I'm running Oracle Database 10g 10.2 on solaris
I configure Oracle text if i look for in a varchar2 column is ok, but with blob column doesn't works the search.
I have a table with a blob column which contains document. I load document with Oracle UCM (stellent)
My index scripts is:
CREATE INDEX ORAUCM.FT_IDCCOLL1 ON ORAUCM.IDCCOLL1
(DDOCFULLTEXT)
INDEXTYPE IS CTXSYS.CONTEXT
PARAMETERS('DATASTORE CTXSYS.DEFAULT_DATASTORE FILTER CTXSYS.AUTO_FILTER FORMAT COLUMN DFULLTEXTFORMAT CHARSET
COLUMN DFULLTEXTCHARSET LEXER OCS_IDCCOLL1_LEXER SYNC (ON COMMIT)')
NOPARALLEL;
And my select retunm 0 rows although it will be many documents:
SELECT IdcColl2.dID, dDocName, dDocTitle, dDocType, dRevisionID, dSecurityGroup, dDocAuthor,
dDocAccount, dRevLabel, dFormat, dOriginalName, dExtension, dWebExtension, dInDate, dOutDate,
dPublishType, dRendition1, dRendition2, VaultFileSize, WebFileSize, URL, dFullTextFormat,
dFullTextCharset, DocMeta.*
FROM IdcColl1, DocMeta
WHERE IdcColl1.dID=DocMeta.dID AND (CONTAINS(dDocFullText,'SUBIR') > 0 )
ORDER BY dInDate Desc
Thanks in advance.

Thank you for your answer.
I response your question:
- yes DDOCFULLTEXT is a BLOB column.
- The document that word, excels, whatever. We load the document with UCM (universal Content Management)
because i need full-test search form UCM tool.
- Yes 'subir' containts in the word document.
- select * from CTX_USER_INDEX_ERRORS ;
No rows returned.
- SELECT TOKEN_TEXT FROM DR$FT_IDCCOLL1$I
No rows returned.
- I tried create symplifying index and doen't work.
I tried create table and index context on oracle 10.2.0.3 (test database)and works ok.
I compared both context (test database and ucm database) and i saw a difference:
In ucm database there are these preferences "analyze text"
BEGIN ctx_ddl.create_preference('ORAUCM.', 'WORLD_LEXER'); end;
BEGIN ctx_ddl.create_preference('ORAUCM.', 'DETAIL_DATASTORE'); end;
I don't know if is important diference or no.
Please if you need more information, tell me.
Thanks for your time.

BLOB column in separate tablespace in 9i?

Should a BLOB column go in a separate tablespace in Oracle 9i? And if so, then how to do it?

Should a BLOB column go in a separate tablespacein Oracle 9i?
from documentation
(http://download.oracle.com/docs/cd/B10501_01/appdev.9
20/a96591/adl07mds.htm#117432):
TABLESPACE and LOB Index
Best performance for LOBs can be achieved by
specifying storage for LOBs in a tablespace different
from the one used for the table that contains the
LOB. If many different LOBs will be accessed
frequently, it may also be useful to specify a
separate tablespace for each LOB column or attribute
in order to reduce device contention.
The LOB index is an internal structure that is
strongly associated with LOB storage. This implies
that a user may not drop the LOB index and rebuild
it.
Note:
The LOB index cannot be altered.
And if so, then how to do it? You can specify tablespace during table creation:
create test_table (id number not null,
content blob)
tablespace data
lob (content) store as (tablespace lobs);
/pre]
For existing table:
[pre]
alter table test_table move lob (content) store as
(tablespace lobs);
Thanks for the post and the link!! Do you know if Oracle creates the LOB index on its own? From reading the link, that was the impression I had as if that was handled by Oracle.

Performance of LOB Segments for Blob Columns

Hi,
I am migrating 11,000 rows of tiff images from Informix to Oracle.In Informix the datatype for the image storage is Byte and Oracle we chose it to Blob.
The Blob column is creating lob segment and lob index.
When I do the migration I observe that the size of the lob segment object is increasing rather than the table object.
So due to creation of this lob segment for the Blob column,will there be any performance issues while retrieval of images from the database and Inserting images into into the database.
Can I get all the issues that can be encountered by storing data in blob column in terms of lob segment.
This is very important information for us as the application has lot of SQL queries for retrieving and injecting images in the database.
It will be really apprecialbe if you can provide Information about this.
Thanks & Regards
Ramanathan KrishnaMurthy

I agree with D.Morgan that object type with 250 attributes is doubtful.
I don't like object tables (tables with "row objects") too.
But, your table is a relational table with object column ("column object").
C.J.Date in An introduction to Database Systems (2004, page 885) says:
"... object/relational systems ... are, or should be, basically just relational systems
that support the relational domain concept (i.e., types) properly - in other words, true relational systems,
meaning in particular systems that allow users to define their own types."
1. How will Oracle store the data in the ADT column?...
For some answers see:
“OR(DBMS) or R(DBMS), That is the Question”
http://www.quest-pipelines.com/pipelines/plsql/tips.htm#OCTOBER
and (of course):
"Oracle® Database Application Developer's Guide - Object-Relational Features" 10g Release 2 (10.2)
http://download-uk.oracle.com/docs/cd/B19306_01/appdev.102/b14260/adobjadv.htm#i1006903
Regards,
Zlatko

Help needed in index creation and its impact on insertion of records

Hi All,
I have a situation like this, and the process involves 4 tables.
Among the 4 tables, 2 tables have around 30 columns each, and the other 2 has 15 columns each.
This process contains validation and insert procedure.
I have already created some 8 index for one table, and an average of around 3 index on other tables.
Now the situation is like, i have a select statement in validation procedure, which involves select statement based on all the 4 tables.
When i try to run that select statement, it takes around 30 secs, and when checked for plan, it takes around 21k memory.
Now, i am in a situation to create new index for all the table for the purpose of this select statement.
The no.of times this select statement executes, is like, for around 1000 times of insert into table, 200 times this select statement gets executed, and the record count of these tables would be around one crore.
Will the no.of index created in a table impacts insert statement performace, or can we create as many index as we want in a table ? Which is the best practise ?
Please guide me in this !!!
Regards,
Shivakumar A

Hi,
index creation will most definitely impact your DML performance because when inserting into the table you'll have to update index entries as well. Typically it's a small overhead that is acceptable in most situations, but the only way to say definitively whether or not it is acceptable to you is by testing. Set up some tests, measure performance of some typical selects, updates and inserts with and without an index, and you will have some data to base your decision on.
Best regards,
Nikolay

Fast index creation suggestions wanted

Hi:
I've loaded a table with a little over 100,000,000 records. The table has several indexes which I must now create. Need to do this as fast as possible.
I've read the excellent article by Don Burleson (http://www.dba-oracle.com/oracle_tips_index_speed.htm) but still have a few questions.
1) If the table is not partitioned, does it still make sense to use "parallel"?
2) The digit(s) following "compress" indicate the number of consective columns at the head of the index that have duplicates. True?
3) How will the compressed index effect query performance (vs not compressed) down the line?
4) In the future I will be doing lots and lots of updates on the indexed columns of the records as well as lots of record deletes and inserts into/out-of the table. Will these updates/inserts/deletes run faster or slower given that the indexes are compressed vs if they were not?
5) In order to speed up the sorting, is it better to add datafiles to the TEMP table or create more TEMP tables (remember, running "parallel")
Thanks in Advance

There are people who would argue that excellent and Mr. Burleson do not belong in the same sentence.
1) Yes, you can still use parallel (and nologging) to create the index, but don't expect 20 - 30 times faster index creation.
2) It is the number of columns to compress by, they may not neccesarily have duplicates. For a unique index the default is number of columns - 1, for a non-unique index the default is the number of columns.
3) If you do a lot of range scans or fast full index scans on that index, then you may see some performance benefit from reading fewer blocks. If the index is mostly used in equality predicates, then the performance benefit will likely be minimal.
4) It really depends on too many factors to predict. The performance of inserts, updates and deletes will be either
A) Slower
B) The same
C) Faster
5) If you are on 10G, then I would look at temporary tablespace groups which can be beneficial for parallel operations. If not, then allocate as much memory as possible to sort_area_size to minimize disk sorts, and add space to your temporary tablespace to avoid unable to extend. Adding additional temporary tablespaces will not help because a user can only use one temporary tablespace at a time, and parallel index creation is only one user.
You might want to do some searching at Tom Kyte's site http://asktom.oracle.com for some more responsible answers. Tom and Don have had their disagreements in the past, and in most of them, my money would be on Tom to be corerct.
HTH
John

Associative array type for each blob column in the table

i am using the code in given link
http://www.oracle.com/technology/oramag/oracle/07-jan/o17odp.html
i chnages that code like this
CREATE TABLE JOBS
JOB_ID VARCHAR2(10 BYTE),
JOB_TITLE VARCHAR2(35 BYTE),
MIN_SALARY NUMBER(6),
MAX_SALARY NUMBER(6),
JOBPIC BLOB
CREATE OR REPLACE PACKAGE associative_array
AS
-- define an associative array type for each column in the jobs table
TYPE t_job_id IS TABLE OF jobs.job_id%TYPE
INDEX BY PLS_INTEGER;
TYPE t_job_title IS TABLE OF jobs.job_title%TYPE
INDEX BY PLS_INTEGER;
TYPE t_min_salary IS TABLE OF jobs.min_salary%TYPE
INDEX BY PLS_INTEGER;
TYPE t_max_salary IS TABLE OF jobs.max_salary%TYPE
INDEX BY PLS_INTEGER;
TYPE t_jobpic IS TABLE OF jobs.jobpic%TYPE
INDEX BY PLS_INTEGER;
-- define the procedure that will perform the array insert
PROCEDURE array_insert (
p_job_id IN t_job_id,
p_job_title IN t_job_title,
p_min_salary IN t_min_salary,
p_max_salary IN t_max_salary,
p_jobpic IN t_jobpic
END associative_array;
CREATE OR REPLACE package body SHC_OLD.associative_array as
-- implement the procedure that will perform the array insert
procedure array_insert (p_job_id in t_job_id,
p_job_title in t_job_title,
p_min_salary in t_min_salary,
p_max_salary in t_max_salary,
P_JOBPIC IN T_JOBPIC
) is
begin
forall i in p_job_id.first..p_job_id.last
insert into jobs (job_id,
job_title,
min_salary,
max_salary,
JOBPIC
values (p_job_id(i),
p_job_title(i),
p_min_salary(i),
p_max_salary(i),
P_JOBPIC(i)
end array_insert;
end associative_array;
this procedure is called from .net. from .net sending blob is posiible or not.if yes how

Ok, that won't work...you need to generate an image tag and provide the contents of the blob column as the src for the image tag.
If you look at my blog entry -
http://jes.blogs.shellprompt.net/2007/05/18/apex-delivering-pages-in-3-seconds-or-less/
and download that Whitepaper that I talk about you will find an example of how to do what you want to do. Note the majority of that whitepaper is discussing other (quite advanced) topics, but there is a small part of it that shows how to display an image stored as a blob in a table.

Need to create link to Word Doc in blob column in search results report

I got the Oracle Text boolean search of word documents in a blob column of a table working.
Now I need to be able to create a link in the results report.
I know that Oracle creates a link for each document in the column when you attach a file, I just need to know what the link should be to allow users to open the document in the search results report.
Right now the application is set to do a search in the attached word documents, and in the results window it shows the names of the people who match the search, but it won't allow me to create a link to their resume in the results report.
the name of the table is CONTRACTOR_LIST and the blob column is RESUME.
How would you go about creating a simple link to the word file in the results window?
Here is the code for the query
select score(1) relevance, Name, Resume
from contractor_list
where CONTAINS (resume, :P1_SEARCH, 1) > 0
order by 1 desc
That works, but I can't get it to link to the resume file.
Here is the code I'm using for the link
javascript:popupURL("#RESUMEL#")
This just give me an error page and the the link is
http://server-namer:8080/apex/[datatype]
the error is
Bad Request
The HTTP client sent a request that this server could not understand.
Thanks again!
Edited by: gjones77 on Dec 2, 2008 6:14 AM
Edited by: gjones77 on Dec 2, 2008 7:08 AM

It is within the table I believe (I'm not a DBA or a developer) since I created a BLOB column and then used the file browse feature to allow users to attach a resume to the table in order to be able to perform a search of the attached documents.
I'm just having a hard time pointing the link in the search results report to the document in the blob column.
The information on that page is great if you're trying to create a link to the document on the initial report.
But I created a query using Oracle Text to run a report that does a boolean search of the attached word documents in the table.
When it displays the search results, it doesn't create a link to the document and I can't figure out how to do it.
Here's a link the the instructions I used to create the initial search report with Oracle Text, mind you I only created the index and query, I didn't add in all the link data since they're using documents on websites and I'm using documents in a table.
http://www.oracle.com/technology/products/database/application_express/pdf/apex_text_application_v1.6.pdf
If you can help me with this I'd really appreciate it.
Thanks again.
Greg
Edited by: gjones77 on Dec 2, 2008 8:14 AM

How to store PDF file in BLOB column without using indirect datastore

Hi ,
I want to store a pdf file in a BLOB column.
But , it should be a direct store. I cannot usre indirect datastore.
BLOB column doesn't support indirect datastore. I get the following error.
ERROR at line 1:
ORA-29855: error occurred in the execution of ODCIINDEXCREATE routine
ORA-20000: Oracle Text error:
DRG-10581: indirect datastores cannot be used with long or lob text columns
ORA-06512: at "CTXSYS.DRUE", line 160
ORA-06512: at "CTXSYS.TEXTINDEXMETHODS", line 365
can anyone give me any clue onhow to manage this issue?

Thanks This really helped.
For other readers, I am summarising what I did.
create table test
id number primary key,
docs BLOB
create or replace directory doc_loc
as 'c:\test';
CREATE OR REPLACE PROCEDURE Load_BLOB_From_File (file_name in varchar2)
AS
src_loc bfile:= bfilename('DOC_LOC',Load_BLOB_From_File.file_name);
dest_loc BLOB;
begin
insert into tkctsf15t values(1,empty_blob()) returning docs
into dest_loc;
dbms_lob.open(src_loc,DBMS_LOB.LOB_READONLY);
DBMS_LOB.OPEN(dest_loc, DBMS_LOB.LOB_READWRITE);
DBMS_LOB.LOADFROMFILE(
dest_lob => dest_loc
,src_lob => src_loc
,amount => DBMS_LOB.getLength(src_loc));
DBMS_LOB.CLOSE(dest_loc);
DBMS_LOB.CLOSE(src_loc);
COMMIT;
end;
show errors;
exec Load_BLOB_From_File('test.pdf');
exec ctx_ddl.create_preference('mylex','BASIC_LEXER');
create index testx on test(docs) indextype is ctxsys.context
parameters
('filter ctxsys.AUTO_FILTER LEXER mylex ');
select id from test where contains(docs,'patch')>0;
Thanks Roger once more

Table with BLOB column re-partitioning

Currently I have a table with a blob column Z partitioned on Column X I want to re-partition the table on Column Y is there a quick way of doing this.
INSERT INTO SELECT * has limitations on the blob size I guess.
Can someone explain this?
Edited by: user10229350 on Mar 1, 2010 7:36 AM

I am using hash partitioning looks like split partition doesn't apply for hash partition:
"The SPLIT PARTITION clause of the ALTER TABLE or ALTER INDEX statement is used to redistribute the contents of a partition into two new partitions. Consider doing this when a partition becomes too large and causes backup, recovery, or maintenance operations to take a long time to complete. You can also use the SPLIT PARTITION clause to redistribute the I/O load.
This clause cannot be used for hash partitions or subpartitions."

Importing a table with a BLOB column is taking too long

I am importing a user schema from 9i (9.2.0.6) database to 10g (10.2.1.0) database. One of the large tables (millions of records) with a BLOB column is taking too long to import (more that 24 hours). I have tried all the tricks I know to speed up the import. Here are some of the setting:
1 - set buffer to 500 Mb
2 - pre-created the table and turned off logging
3 - set indexes=N
4 - set constraints=N
5 - I have 10 online redo logs with 200 MB each
6 - Even turned off logging at the database level with disablelogging = true
It is still taking too long loading the table with the BLOB column. The BLOB field contains PDF files.
For your info:
Computer: Sun v490 with 16 CPUs, solaris 10
memory: 10 Gigabytes
SGA: 4 Gigabytes

Legatti,
I have feedback=10000. However by monitoring the import, I know that its loading average of 130 records per minute. Which is very slow considering that the table contains close to two millions records.
Thanks for your reply.

BLOB column not updating using automated row processing

I have fiddled around with creating a simple application to understand how APEX handles images stored in blobs - did a simple app that stores them, gets them, displays them. it all works great.
so i have this existing table/application that i am trying to add a BLOB column to here's what i did:
it's a pretty simple form on a table with report application. just one table.
I added the BLOB to the table (and the other mimetype etc cols as well).
i added the page items to the form page.
i basically made everything identical in terms of page item settings and such to the working simple application.
so here's the problem... when i run the application and update a row, the BLOB column isn't updating. neither are the mimetype or filename columns. the activity date col is.
and here's another interesting thing. i quickly created another form and report pair on the same table, and when i ran it, it updates the blob col just fine.
why is my original form not updating it? what can i do to remedy this? any ideas? i've gone though setting by setting for the blob page item and the one that works is identical to the one that doesn't.
i'm using the automatic row processing to update the table.
Edited by: moo on Jun 23, 2011 5:33 AM

Gary,
The DML processes (and the creation wizards for them) are for use with items having source type Database Column. If your page items don't use this source type, then neither the Automated Row Fetch nor the Automatic Row Processesing (DML) process types will work.
Scott

CONTEXT index creation - performance!

Hi,
I have a table with about 5Million rows. The content that needs to be indexed is of RAW datatype. The average size (length) of this field is about 50 characters (it could be more).
I am trying to index this column to perform a keyword search. DEtails are furnished below.
table:
SQL> desc kwtai
Name Null? Type
TSD_HH24 DATE
COUNTRY_CODE_ALPHA_2 VARCHAR2(2)
ONETWORK NUMBER(6)
OADDRESS VARCHAR2(25)
DNETWORK NUMBER(6)
DADDRESS VARCHAR2(25)
MESSAGE_LENGTH NUMBER
MESSAGE_CONTENT RAW(2000)
Preferences:-
begin
Ctx_Ddl.Create_Preference('mc_storage', 'BASIC_STORAGE');
ctx_ddl.set_attribute('mc_storage','I_TABLE_CLAUSE',
'tablespace large_index storage (initial 10M next 10M)');
ctx_ddl.set_attribute('mc_storage', 'K_TABLE_CLAUSE',
'tablespace large_index storage (initial 10M next 10M)');
ctx_ddl.set_attribute('mc_storage', 'R_TABLE_CLAUSE',
'tablespace large_index storage (initial 1M) lob (data) store as (cache)');
ctx_ddl.set_attribute('mc_storage', 'N_TABLE_CLAUSE',
'tablespace large_index storage (initial 1M)');
ctx_ddl.set_attribute('mc_storage', 'I_INDEX_CLAUSE',
'tablespace large_index storage (initial 1M) compress 2');
ctx_ddl.create_preference('mc_lex', 'BASIC_LEXER');
ctx_ddl.set_attribute('mc_lex', 'skipjoins', '_-"''`~!@#$%^&*()+=|}{[]\:;<>?/.,');
ctx_ddl.set_attribute('mc_lex', 'INDEX_STEMS','NONE');
end;
create index kwtaidx on kwtai (message_content) indextype is ctxsys.context
parameters (' lexer mc_lex storage mc_storage memory 500M ')
parallel 16;
This create index takes about 4 hours to complete on a 8CPU dual core machine.
This is on Oracle 10g (10.2.0.4)
The reason i am creating the index as opposed to syncing it is because the data gets loaded into this table only once a day and it gets cleared once my keyword analysis is done.
Any pointers to speed up the index creation will be really appreciated! Thanks in advance!

My base table has the text that needs to be indexed stored in the "MESSAGE_CONTENT" column which for now is RAW data type. The data stored in this table are in hex representation.
Some examples -
MESSAGE_CONTENT
616C70686120626574612067616D6D612064656C746120657073696C6F6E207A657461206E69F16F
616C70686120626574612067616D6D612064656C746120657073696C6F6E207A657461
616C70686120626574612067616D6D612064656C746120657073696C6F6E207A657461206E69C3B16F
6865792E2C2C77686174277320676F696E67206F6E2E2E2E7066206368616E67277320697320736F6D652072657374617572616E742E2074686579206172652070736564756F2D636F6F6C
54686520477265656B20616C7068616265742069732074686520736372697074207468617420686173206265656E
54686520477265656B20616C7068616265742069732074686520736372697074207468617420686173206265656E20706F73742D64617461
Now with your suggestion i tried to bypass this. So what i did was added a format column to my base table and updated it to "TEXT". My database is in UTF8.
Now when i create the index with the following preferences it takes less than a minute.
begin
Ctx_Ddl.Create_Preference('kwta_storage', 'BASIC_STORAGE');
ctx_ddl.set_attribute('kwta_storage','I_TABLE_CLAUSE',
'tablespace TEXT_INDEX storage (initial 10M next 10M)');
ctx_ddl.set_attribute('kwta_storage', 'K_TABLE_CLAUSE',
'tablespace TEXT_INDEX storage (initial 10M next 10M)');
ctx_ddl.set_attribute('kwta_storage', 'R_TABLE_CLAUSE',
'tablespace TEXT_INDEX storage (initial 1M) lob (data) store as (cache)');
ctx_ddl.set_attribute('kwta_storage', 'N_TABLE_CLAUSE',
'tablespace TEXT_INDEX storage (initial 1M)');
ctx_ddl.set_attribute('kwta_storage', 'I_INDEX_CLAUSE',
'tablespace TEXT_INDEX storage (initial 1M) compress 2');
ctx_ddl.create_preference('mylex', 'BASIC_LEXER');
ctx_ddl.set_attribute('mylex', 'skipjoins', '_-"''`~!@#$%^&*()+=|}{[]\:;<>?/,');
ctx_ddl.set_attribute('mylex','punctuations','.?!');
ctx_ddl.set_attribute('mylex', 'INDEX_STEMS','NONE');
ctx_ddl.set_attribute('mylex', 'continuation','\-');
Ctx_Ddl.Create_Stoplist ( 'mystop' );
Ctx_Ddl.Add_Stopword ( 'mystop', 'is' );
Ctx_Ddl.Add_Stopword ( 'mystop', 'has' );
Ctx_Ddl.Add_Stopword ( 'mystop', 'the' );
Ctx_Ddl.Add_Stopword ( 'mystop', 'that' );
end;
create index kwtaidx on kwtai (message_content) indextype is ctxsys.context
parameters ('filter ctxsys.auto_filter format column fmt stoplist mystop lexer mylex storage kwta_storage memory 500M')
parallel 16;
When i select distinct tokens from the $I table i get the following
TOKEN_TEXT
RESTAURANT
GREEK
WHATS
ARE
DELTA
ZETA
ALPHA
ALPHABET
EPSILON
PF
PSEDUOCOOL
SOME
CHANGS
NIÃO
ON
POSTDATA
SCRIPT
BEEN
GAMMA
GOING
HEY
NI
O
THEY
BETA
Now what i am also wondering is if the text (message_content column) is being converted to UTF8 (database characterset) by using AUTO_FILTER. Is my assumption correct? Not sure how to validate this?
And, would you kindly share of why RAW must not be used in this case?
Thanks for all your pointers!

Index creation online - performance impact on database

hi,
I have oracle 11.1.0.7 database running on Linux as 3 node RAC.
I have a huge table which has more than 255 columns and is about 400GB in size which is also highly fragmented because of constant DML activities.
Questions:
1. For now i am trying to create an index Online while the business applications are running.
Will there be any performance impact on the database to create index Online on a single column of a table 'TBL' while applications are active against the same table? So basically my question will index creation on a object during DML operations on the same object have performance impact on the database? is there a major performance impact difference in the database in creating index online and not online?
2. I tried to build an index on a column which has NULL value on this same table 'TBL' which has more than 255 columns and is about 400GB in size highly fragmented and has about 140 million rows.
I requested the applications to be shutdown, but the index creation with parallel of 4 a least took more than 6 hours to complete.
We have a Pre-Prod database which has the exported and imported copy of the Prod data. So the pre-Prod is a highly de-fragmented copy of the Prod.
When i created the same index on the same column with NULL, it only took 15 minutes to complete.
Not sure why on a highly fragmented copy of Prod it took more than 6 hours compared to highly defragmented copy of Pre-Prod where the index creation took only 15 minutes.
Any thoughts would be helpful.
Thanks.
Phil.

How are you measuring the "fragmentation" of the table ?
Is the pre-prod database running single instance or RAC ?
Did you collect any workload stats (AWR / Statspack) on the pre-prod and production systems while creating (or failing to create) the index ?
Did you check whether the index creation ended up in-memory, single pass or multi pass in in the two environments ?
The commonest explanation for this type of difference is two-fold:
a) the older data needs a lot of delayed block cleanout, which results in a lot of random I/O to the undo tablespace - slowing down I/O generally
b) the newer end of the table is subject to lots of change, so needs a lot of work relating to read-consistency - which also means I/O on the undo system
-- UPDATED: but you did say that you had stopped the application so this bit wouldn't have been relevant.
On top of this, an online (re)build has to lock the table briefly at the start and end of the build, and in a busy system you can wait a long time for the locks to be acquired - and if the system has been busy while the build has been going on it can take quite a long time to apply the journal file to finish the index build.
Regards
Jonathan Lewis

Index creation on Blob column

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