Query on Materialized View Logs

We need a denormalised data step-up, we decided on implementing Materialized Views and started working on them. I have created Materialized View log on a table using below mentioned syntax
CREATE MATERIALIZED VIEW LOG ON <table_name> WITH ROWID
I have tested it and its working fine.A Strange error I am facing is, after an hour or so the materialised view gets corrupted and applicatin users gets an error saying error with the materialised view log.
The log entry in the data dictionary gets deleted. Later I have to execute DROP on the log to completely remove it.
I am confused how this can happen.

What is the refresh method set as?
Could you paste the full MV log creation script and the corresponding MV creation script.

Similar Messages

Help with sql query on materialized view logs

I am in need of a query to find out what tablespace and snap shot site a long list of materialized view logs are associated with.
something like below except tablespace and snap_shot_site are not an option for this table.
select log_owner, master, log_table, tablespace, snap_shot_site from dba_mview_logs;

What is the refresh method set as?
Could you paste the full MV log creation script and the corresponding MV creation script.

Query on Materialized view and materialized view log

I am creating a materialized view something like this.but getting following error:
ERROR at line 1:
ORA-12032: cannot use rowid column from materialized view log on "SCOTT"."EMP"
SQL> create snapshot log on scott.emp;
Materialized view log created.
SQL> create materialized view scott_emp refresh fast on demand as select deptno,sum(sal) sum_sal from scott.emp group by deptno;
ERROR at line 1:
ORA-12032: cannot use rowid column from materialized view log on "SCOTT"."EMP"
Note when i have my query in materialized view as "select * from emp;" in place of
"select deptno,sum(sal) sum_sal from scott.emp group by deptno;" This code works fine.
How do i have a materialized with with a group by clause.
Thanks in Advance

Got the answer myself.
I wasnt adding all the required columns.
CREATE MATERIALIZED VIEW LOG ON scott.emp
WITH SEQUENCE, ROWID (<all the required columns>)
INCLUDING NEW VALUES;
Anyways,
Thanks guys...

Materialized View Logs Query

Hi All,
I had some problem with my Materialized views, that's why Dropped all of the Logs + Materialized Views from my Production Database. Kindly tell me that, Is there any Query, which I can run and make Materialized View Logs from my Existing Tables . Thanks
Regards,
Imran

Incremental Materialized View creation steps
Hi,
Find the below steps to create MV's with logs.
1.     Materialized view log creation at master.
2.     DB link creation at MV site to master site.
3.     Materialized view creation at MV site.
4.     Refresh the MV.
Materialized view log creation at master.
SQLPLUS <USER_MASTER_SITE>/<PASSWORD>@<MASTER_SITE>
CREATE MATERIALIZED VIEW LOG ON <TABLE_NAME>;
DB link creation at MV site.
SQLPLUS <USER_MV_SITE>/<PASSWORD>@<MV_SITE>
CREATE Database Link <MASTER_SITE> Connect To <USER_MASTER_SITE> Identified By <PASSWORD> Using ‘<tnsnames>’
Materialized view creation at MV site.
SQLPLUS <USER_MV_SITE>/<PASSWORD>@<MV_SITE>
CREATE MATERIALIZED VIEW <TABLE_NAME> BUILD
IMMEDIATE REFRESH FAST ON DEMAND
ENABLE QUERY REWRITE
AS SELECT * FROM <TABLE_NAME>@<MASTER_SITE> REFRESH ;
Refresh the MV.
SQLPLUS <USER_MV_SITE>/<PASSWORD>@<MV_SITE>
Execute DBMS_SNAPSHOT.REFRESH( '<TABLE_NAME>','f');
Regards,
Prasanna

UPDATING the query in materialized view

Hi,
i have a little doubt in Materialized view. i created a materialized view and log with the following query,
create table test_mv (a number ,b number )
alter table test_mv add constraint t_pk primary key ( a );
insert into test_mv values (1,2);
insert into test_mv values(2,2);
insert into test_mv values(3,2);
insert into test_mv values(4,2);
insert into test_mv values(5,2);
commit;
CREATE MATERIALIZED VIEW LOG ON test_mv
WITH SEQUENCE, ROWID
*(a,b)*
INCLUDING NEW VALUES;
CREATE MATERIALIZED VIEW product_sales_mv
ENABLE QUERY REWRITE
AS SELECT b from test_mv;
Now i want to update the query in the MV as 'Select a from test_mv' . for that i tried with
*'ALTER MATERIALIZED VIEW product_sales_mv AS SELECT a from test_mv;'*
But it throwing error,
Error starting at line 5 in command:
alter MATERIALIZED VIEW product_sales_mv AS SELECT b from test_mv
Error report:
SQL Error: ORA-00933: SQL command not properly ended
+00933. 00000 - "SQL command not properly ended"+
*Cause:+
*Action:+
i guess i am doing wrong. kindly help me here. i want to update it without drop and recreate.
thanks,
Jeevanand.Ke

Hi Jeeva,
No. you cannot add or drop columns to the materialized view using the ALTER Statement.
To Change the Structure of the view , drop and re-create the materialized view.
To Alter a materialized view log, You can use the ALTER MATERIALIZED VIEW LOG. By this,
You can add new columns to a materialized view log.
ALTER MATERIALIZED VIEW LOG ON sggi_mrps.emp ADD(deptno);Thanks,
Shankar
Edited by: Shankar Viji on Aug 24, 2012 2:11 AM

Can't update master table when creating a materialized view log.

Hi all,
I am facing a very strange issue when trying to update a table on which I have created a materialized view log (to enable downstream fast refresh of MV's). The database I am working on is 10.2.0.4. Here is my issue:
1. I can successfully update (via merge) a dimension table, call it TABLEA, with 100k updates. However when I create a materialized view log on TABLEA the merge statement hangs (I killed the query after leaving it to run for 8 hrs!). TABLEA has 11m records and has a number of indexes (bitmaps and btree) and constraints on it.
2. I then create a copy of TABLEA, call it TABLEB and re-created all the indexes and constraints that exist on TABLEA. I created a materialzied view log on TABLEB and ran the same update....the merge completed in under 5min!
The only difference between TABLEA and TABLEB is that the dimension TABLEA is referenced by a number of FACT tables (by FKs on the FACTS) however this surely should not cause a problem. I don't understand why the merge on TABLEA is not completing...even though it works fine on its copy TABLEB? I have tried rebuilding the indexes on TABLEA but this did not work.
Any help or ideas on this would be most appreciated.
Kind Regards
Mitesh
email: [email protected]

Thats what I thought, the MVL will only read data that has changed since it was created and wont have the option to load in all the data as though it was made before the table was created.
From what I have read, the MVL is quicker than a Trigger and I have some free code that prooved to work from a MVL using it as a reference to know what records to update. There is not that much to a MVL, a record ID and type of update, New, Update or Delete.
I think what I will have to do is work on a the same principle for the MVL but use a Trigger as this way we can do a full reload if required at any point.
Many thanks for your help.

Materialized view logs pretty huge!

Hi,
I have a table MLOG$_XXXXX, which i guess is a materialized view log table. It is huge in size (80GB) and is growing at a very alarming rate.
Could someone please help me to reduce the size of this table?
How do I find out which materialized view is causing this table to grow? Is there any query through which I can find this out?
The database is of version 10204 and is running on HP Unix (B.11.11).
Thanks!

The materialized views in the database are:
SQL> select mview_name, owner, updatable, refresh_mode, last_refresh_date from dba_mviews;
MVIEW_NAME                     OWNER      U REFRESH_MODE    LAST_REFRESH_DATE
MV_EXCH_RT                     SYS        N COMMIT          03 JUN 2010 12:02:59
ADMIN_MGMT_CO                  JJORA      N DEMAND          06 JUL 2010 01:37:39
REG                            JJORA      N DEMAND          06 JUL 2010 01:37:39
CNTRY                          JJORA      N DEMAND          06 JUL 2010 01:37:39
OPER_GRP                       JJORA      N DEMAND          06 JUL 2010 01:37:39
ADMIN_CO                       JJORA      N DEMAND          06 JUL 2010 01:37:39
MV_JJGL_SUB_CD_141P            JJGL       N DEMAND          06 JUL 2010 01:24:43
7 rows selected.The table which grows at an alarming rate is:
SQL> select sum(bytes)/1024/1024/1024 from dba_segments where segment_name like 'MLOG$_XXXXX%';
SUM(BYTES)/1024/1024/1024
               77.8789063Now how do I find out, which materilized view is causing this table to grow? Can someone please provide me the query?
Thanks!
Edited by: user9104898 on Jul 6, 2010 8:11 AM

Materialized View Log

Hi,
I would like to create Fast refresh Materialized View in owb
Create Materialized View F_CALL_DAY_MV PARALLEL LOGGING BUILD IMMEDIATE REFRESH FAST ENABLE QUERY REWRITE AS
SELECT
FCALL.ACCOUNT_DIM_ID,
FCALL.INVOICE_DIM_ID,
FCALL.SCHEDULER_DIM_ID,
FCALL.CHAIRPERSON_DIM_ID,
FCALL.DATE_DIM_ID,
FCALL.RESERVATION_DIM_ID,
FCALL.PRODUCT_DIM_ID,
FCALL.CALL_STATUS_DIM_ID,
FCALL.REVENUE_CENTER_DIM_ID,
FCALL.CAMPAIGN_DIM_ID,
FCALL.SALESPERSON_DIM_ID,
count(*),
count (FCALL.CAMPAIGN_ELAPSED_DAYS_TO_CALL) cnt_CAMP_ELAPSED_DAYS_TO_CALL,
AVG(FCALL.CAMPAIGN_ELAPSED_DAYS_TO_CALL) AVG_CAMP_ELAPSED_DAYS_TO_CALL,
SUM(FCALL.SCHEDULED_CONNECTIONS) SCHEDULED_CONNECTIONS,
SUM(FCALL.ACTUAL_CONNECTIONS) ACTUAL_CONNECTIONS,
DDATE.THE_DATE,
DDATE.YEAR_NUM,
DDATE.MONTH_NUM,
DDATE.WEEK_OF_THE_YEAR,
DACCOUNT.BILL_ACCOUNT_CD,
DACCOUNT.ACCOUNT_NM,
DCHAIRPERSON.CONTACT_FULL_NAME,
DCHAIRPERSON.CONTACT_FULL_ADDRESS,
DCHAIRPERSON.MAIN_PHONE_NUM,
DCHAIRPERSON.MOBILE_PHONE_NUM,
DCHAIRPERSON.EMAIL_ADDR
FROM F_CALL FCALL,
D_ACCOUNT DACCOUNT,
D_CALL DCALL,
     D_INVOICE D_INVOICE,
     D_SCHEDULER DSCHEDULER,
     D_CHAIRPERSON DCHAIRPERSON,
     D_DATE DDATE,
     D_RESERVATION DRESERVATION,
D_PRODUCT DPRODUCT,
     D_CALL_STATUS DCALLSTATUS,
     D_REVENUE_CENTER DREVENUECENTER,
     D_CAMPAIGN DCAMPAIGN,
     D_SALESPERSON DSALESPERSON
WHERE FCALL.ACCOUNT_DIM_ID = DACCOUNT.ACCOUNT_DIM_ID
AND FCALL.CALL_DIM_ID = DCALL.CALL_DIM_ID
AND FCALL.INVOICE_DIM_ID = D_INVOICE.INVOICE_DIM_ID
AND FCALL.SCHEDULER_DIM_ID = DSCHEDULER.SCHEDULER_DIM_ID
AND FCALL.CHAIRPERSON_DIM_ID = DCHAIRPERSON.CHAIRPERSON_DIM_ID
AND FCALL.DATE_DIM_ID = DDATE.DATE_DIM_ID
AND FCALL.RESERVATION_DIM_ID = DRESERVATION.RESERVATION_DIM_ID
AND FCALL.PRODUCT_DIM_ID = DPRODUCT.PRODUCT_DIM_ID
AND FCALL.CALL_STATUS_DIM_ID = DCALLSTATUS.CALL_STATUS_DIM_ID
AND FCALL.REVENUE_CENTER_DIM_ID = DREVENUECENTER.REVENUE_CENTER_DIM_ID
AND FCALL.CAMPAIGN_DIM_ID = DCAMPAIGN.CAMPAIGN_DIM_ID
AND FCALL.SALESPERSON_DIM_ID = DSALESPERSON.SALESPERSON_DIM_ID
GROUP BY
FCALL.ACCOUNT_DIM_ID,
FCALL.INVOICE_DIM_ID,
FCALL.SCHEDULER_DIM_ID,
FCALL.CHAIRPERSON_DIM_ID,
FCALL.DATE_DIM_ID,
FCALL.RESERVATION_DIM_ID,
FCALL.PRODUCT_DIM_ID,
FCALL.CALL_STATUS_DIM_ID,
FCALL.REVENUE_CENTER_DIM_ID,
FCALL.CAMPAIGN_DIM_ID,
FCALL.SALESPERSON_DIM_ID,
DDATE.THE_DATE,
DDATE.YEAR_NUM,
DDATE.MONTH_NUM,
DDATE.WEEK_OF_THE_YEAR,
DACCOUNT.BILL_ACCOUNT_CD,
DACCOUNT.ACCOUNT_NM,
DCHAIRPERSON.CONTACT_FULL_NAME,
DCHAIRPERSON.CONTACT_FULL_ADDRESS,
DCHAIRPERSON.MAIN_PHONE_NUM,
DCHAIRPERSON.MOBILE_PHONE_NUM,
DCHAIRPERSON.EMAIL_ADDR
For this i need to create Materialized View Log as specified below for all the tables
used for creating above MV
CREATE MATERIALIZED VIEW LOG ON D_SALESPERSON
WITH ROWID, SEQUENCE(SALESPERSON_DIM_ID)
INCLUDING NEW VALUES;
But i'm not able to create MV log in oracle warehouse builder as specified above. When i specify base tables in owb it creates default mv log as
CREATE MATERIALIZED VIEW LOG ON D_SALESPERSON but i need to create MV log with "WITH ROWID, SEQUENCE(SALESPERSON_DIM_ID)
INCLUDING NEW VALUES"
Please could you help me to resolve this issue
Thanks
Kavitha

Hi,
I would just create the MV Log manually from SQL*Plus.
Best regards,
Erik

How to create materialized view log on remote database

How do you create materialized view logs on a remote database.
I tried
create materialized view log on global_express_views.vccs438_project_work_request@h92edwp with sequence, rowid ( columns...)
ERROR at line 1:
ora-00949 illegal reference to remote database

Hi,
I am not getting the error exactly. But have some suggestion:
If the schema owner does not own the master tables, then the schema owner must have the GLOBAL QUERY REWRITE privilege or the QUERY REWRITE object privilege on each table outside the schema.
Hope, this may help you?
Thanx.. Ratan

Materialized View Log Error

I keep getting a materialized view log error on a table that is not a master table, in fact there are no materialized views created on any tables in this database. The schema was imported from another but the export schema did not have any materialized views either from what I can see.
Is there a data dictionary or something I can check?
This is the error: ORA-12096: error in materialized view log on "Schema"."Table".
ORA-00942: table or view does not exist
I get this error anytime I try to update or insert.
Apparently it thinks it should be associated to a materialized view log, how can I disassociate it?
Thanks

Hey Justin, thanks for your reply. I did not use the real table names but the original error message did.
There was a log when I queried the view. I dont know why there was one. We never created any materialized views in or from this database.
I dropped the log. It took it out of the data dictionary so everything works again.
Thanks for your reply.

Materialized View Log options

I have read the documentation. I know you can specify options such as 'with primary key' and/or 'with rowid' when creating a materialized view log. Also, that you can specify to include additional columns in the log -and that these can then be seen in the MLOG$ table that gets created. But I don't know why or in what circumstances you'd specify the one or the other, or include columns or not. Can anyone give some example scenarios where you'd do one or the other?

Hello again,
The fundamental reason (why you would specify primary key and/or ROWID) is to facilitate fast refreshes (as opposed to a complete refresh) of the materialized view -- a lot will depend on the MV query itself, and whether one or both of primary key & ROWID are needed, i.e., if there's a COUNT(*) involved, where the primary key would play a role, or without such an aggregate, the ROWID will be necessary (in any case) for fast refresh.
Edited by: SeánMacGC on Jul 9, 2009 5:54 PM
If you run the utlxmv.sql script in $ORACLE_HOME/rdbms/admin, that will create the MV_CAPABILITIES_TABLE, which when you create an MV and execute DBMS_MVIEW.EXPLAIN_MVIEW('your_mview') will populate that with what that MV is capable of, i.e.,
SQL> desc mv_capabilities_table;
Name                                      Null?    Type
STATEMENT_ID                                       VARCHAR2(30)
MVOWNER                                            VARCHAR2(30)
MVNAME                                             VARCHAR2(30)
CAPABILITY_NAME                                    VARCHAR2(30)
POSSIBLE                                           CHAR(1)
RELATED_TEXT                                       VARCHAR2(2000)
RELATED_NUM                                        NUMBER
MSGNO                                              NUMBER(38)
MSGTXT                                             VARCHAR2(2000)
SEQ                                                NUMBER
SQL> select capability_name, possible from mv_capabilities_table;
CAPABILITY_NAME                P
PCT                            N
REFRESH_COMPLETE               Y
REFRESH_FAST                   N
REWRITE                        N
PCT_TABLE                      N
REFRESH_FAST_AFTER_INSERT      N
REFRESH_FAST_AFTER_ONETAB_DML N
REFRESH_FAST_AFTER_ANY_DML     N
REFRESH_FAST_PCT               N
REWRITE_FULL_TEXT_MATCH        N
REWRITE_FULL_TEXT_MATCH        N
REWRITE_PARTIAL_TEXT_MATCH     N
REWRITE_PARTIAL_TEXT_MATCH     N
REWRITE_GENERAL                N
REWRITE_GENERAL                N
REWRITE_PCT                    N
PCT_TABLE_REWRITE              N

Materialized View Log not empty

Hello all
I have an oracle database (11g version), connecting via dbLink to another DB (10g version), and using it's tables as masters for fast refresh materialized views.
To make it simple: I have master DB, with master table X, and Materialized View Log MLOG$_X.
Then, I have replicate DB, with dblink pointing to Master, and Materialized View MV_X, using X.
The materialized view is refreshed fast, on demand.
The problem is, the MV log is never getting empty... how can I solve this issue?
/* code for creating MView */
CREATE MATERIALIZED VIEW "MY_USER"."SI_BANK" ("ID", "NAME", "ACRONYM")
ORGANIZATION HEAP PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
STORAGE(INITIAL 163840 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "USERS"
BUILD IMMEDIATE
USING INDEX
REFRESH FAST ON DEMAND START WITH sysdate+0 NEXT SYSDATE + 1
WITH PRIMARY KEY USING DEFAULT LOCAL ROLLBACK SEGMENT
USING ENFORCED CONSTRAINTS DISABLE QUERY REWRITE
AS SELECT ibanco id, nbanco name, nsigla acronym FROM USER.tgtbanc0@DB_LINK;
/* code for refresh group*/
BEGIN
DBMS_REFRESH.MAKE ( name => 'si2p_grp',
list => '', next_date => 'SYSDATE +1' , interval => 'SYSDATE + 1', implicit_destroy => FALSE, rollback_seg => '', push_deferred_rpc => TRUE, refresh_after_errors => FALSE);
END;
/* ADD MATERIALIZED VIEWS TO GROUP */
BEGIN
DBMS_REFRESH.ADD ( name => 'si2p_grp', list => 'SI_BANK', lax => TRUE);
END;
Thank you for any help

One MV log serve to many materialized views. Check dba_registered_mviews on master DB to see how many MViews you have build on you master table X.
After MV (materialized view) is refreshed than all data logged in MVlog for this MV are deleted. But new are recorded when DML are performed against table X.
If you can stop DML on table X for some period of time then do MV refresh and then you can see that MVlog is empty.

Performance consequences to adding materialized view logs to tables?

I am writing a very complex query for a client of our transactional database system and this will require the creation of a materialized viewbecause all attempts at tuning to make performance acceptable have failed.
I want to enable fast refresh of the MVIEW but I am confused regarding the consequences of the addition of adding materialized view logs to the base tables.
Some of the tables are large and involved in alot of transactions and I am wondering if the performance of INSERT/UPDATES will be seriously affected by the presence of an mview log.
This may be a simple question to answer but I was unable to find a clear cut answer in the literature.
Thanks for any answers!!
Chris Mills
Biotechnology Data Management Consultant

Last time i looked into this there were three cases to consider
If you're doing conventional row-by-row DML then the impact is just one insert into a heap table per row modified.
If you are modifying a high number of rows using bulk-binds then the overhead is very severe because modifying 1,000 rows on the base table causes 1,000 non-bulk bound inserts into the log table.
Direct path inserts have extremely low overhead because the MV log is not touched. Instead, the range of new rowids added is logged in ALL_SUMDELTA
http://oraclesponge.wordpress.com/2005/09/15/optimizing-materialized-views-part-ii-the-direct-path-insert-enhancement/

Select query in materialized view with two dblinks

Hi All,
We have oracle 10g On windows.
We are trying to create materialized view. Scenario is we have base table on other database and we are creating mview on different database.
Basa database have two schema's and i am selecting records from that two schema's using two private db links.
But when i am tryin gto create mview its not getting created. After 15 hrs. its still showing creation command and not finished.
Query is :-
Is it good practice to have two db links in select query of materialized view.

Billy Verreynne wrote:
Chanchal Wankhade wrote:
Is it good practice to have two db links in select query of materialized view.Same db link being used twice, or two different db links?
If the former, you ideally want the local Oracle db to send the join to the remote database, and for the remote database to drive the join between those 2 tables. There is a hint (<i>driving_site</i>) that can be used - or the join query can be defined on the remote database as a view, and the local materialised view can then use that remote view.
If you have 2 different db links and joining across these - usually a bad idea to perform distributed database joins. There are lots of limitations as to how the tables can be joined. Worse case, full table scans of both remote tables, pulling all the rows from the 2 remote database tables to the local database, and joining these on the local database.
I have seen some severe performance issues in the past as a result of distributed joins. I'll rather use 2 materialised views for pulling both distributed tables's data locally, and then do the join on local data (using indexes, partition pruning, etc)Hi Billy,
My scenario is i have two database database A and database B. Database A is having two schema's SCOTT AND HR. SCOTT schema have select privileges on HR schema.
DB LINK is between Database B to Database A. name is db.link.B.A.oracle.com.
What if i priovide while creating materialized view, the schema name before the table name in database B for this particuler table so it will pick up the table from that schema using same DB LINK(db.link.B.A.oracle.com.) that i am using to fetch records from SCOTT schema.
Above schnario is like two base schema's and one db link using two schema.

Creating a Materialized View Log After the Data has been instered

Hi,
I am trying to create a method of replication from Oracle to MySQL using the Materialized View Log table.
This has been done before and works quite well, the only problem is that I am trying to impliment the log after the table has been created and populated and wish to push all the existing data through the log file...
Does anyone know if it is possible to refresh the Materialized View Log and not a Materialized View.
The way the replication is intended to work is:
Oracle> Data inserted into table
Oracle> writes the vector data to the MVL
Script> Monitors the MVL and can see the changes being made to the Oracle Table
Script> Updates MySQL with the data and removes the rows from the MVL
MySQL is then used with other unix systems
Currently we export the data from the table using Triggers and a cronjob running every x minute to check for changes in the TriggerTables
Many thanks for your time on this, I have been checking for almost a whole working day and not found the answer to this problem.

Thats what I thought, the MVL will only read data that has changed since it was created and wont have the option to load in all the data as though it was made before the table was created.
From what I have read, the MVL is quicker than a Trigger and I have some free code that prooved to work from a MVL using it as a reference to know what records to update. There is not that much to a MVL, a record ID and type of update, New, Update or Delete.
I think what I will have to do is work on a the same principle for the MVL but use a Trigger as this way we can do a full reload if required at any point.
Many thanks for your help.

Query on Materialized View Logs

Similar Messages

Maybe you are looking for