Store Previous Data in Materialized Views

Hello All,
Thanks in Advance for sharing knowledge.We have a materialized view and using Oracle 10g.
Is there any way we can store previous data as well as have new data in the materialized view.
I mean it would have old as well as new data.
Regards
Rahul

Thanks for your prompt reply.I am not looking for flashback query.
Actually i have to send the data to user and materialized view would only most recent data after refresh,but i would like to have the previous data before refresh and new data after refresh.
Regards
Rahul

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Storing missing data in Materialized View

There is 1 View which contains all the web activities on each day and I am extracting summary data as follows.
1. Date
2. User Access counts on the date
But the base table of this view consists of 2 table, log1 and log2, and each
table is switched each 14 days. So, this view can reference the data until
maximum 28 days.
In this environment, I am planning to store the summary data which is made
before 28 days, using Materialized View. But can Materialized View store the
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and keep past data as it is in the Materialized View.

Thank you for the reply.
So, once the materialized view is refreshed, the previous data will be cleared, right? I wanted to store old data and add new data at the same time, but it seems to be impossible.
In our environment, table Log1 and Log2 are used alternately. So, once 14 days data are stored in Log1, new log data will be written into Log2 table and after another 14 days, the new log data will be written in Log1 Table. So, Maximum 28 days data can be stored.

Moving data from Materialized View to downstream application

Database Version: 9i Release 2
I've created a Materialized View on a base table, the purpose of which is to capture data changes to send to a downstream application
(I've been advizsed to avoid using Streams for now until we upgrade to 10g)
I need to either:
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or
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Some notes/questions
I cannot change the structure of the underlying base table
On the MV I could capture a date-time which records each time a record is touched on the base table, the problem is that many of these updates are “meaningless” and I should not send such updates downstream
1.Is there a way I can timestamp/flag the records as they get inserted/updated on the MV? (potentially used by the pickup process to identify what it needs to pick up)
2. If I flag the records e.g. “needs pickup” – would it be ok to make the MV updateable so the process can then mark the records as “picked up”. Performance?
3. Can I create a trigger on the MV to write records to a secondary table as they are inserted/updated on the MV?
4. Could I use the MV log tables MLOG$ to help me in any way?
I’m guessing there is no way to do the following but:
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Yes I do have a unique identifier on each record in the base table and therefore also in the MV.
So now the Downstream application has to update some of its own database tables based on what is in the MV that I provide - just so I understand how would that work e.g.:
1. MV gets refreshed from my base table every minute
2. Some records are newly inserted and some simply updated
and this is the part I don't understand (I might be missing something obvious)....
3. Downstream application interrogates the MV every (say 1-2 minutes) and updates its own tables based on the data there.....but let's say MV contains 10,000 records and in the last minute 100 of those records have been updated and another 100 inserted - how will it know the 200 records it needs to pull?
Thanks again

Materialized view fast refresh with date field

I have a situation where I need to create a materialized view worth of 6 months of data with fast refresh option from the master table. Somehow whenever I have the where clause added with the date field then it craps out with "ORA-12015: cannot create a fast refresh materialized view from a complex query".
Here is what I am trying to do. Please let me know if there is any other way to accomplish this.
create table test (id number, date_time DATE);
CREATE MATERIALIZED VIEW LOG ON test WITH ROWID;
CREATE MATERIALIZED VIEW cms.scoreboard_statistics_mv
BUILD IMMEDIATE
REFRESH FAST
WITH ROWID
AS
SELECT * from test
WHERE date_time >= sysdate - 180;
ORA-12015: cannot create a fast refresh materialized view from a complex query
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It's crazy but a new time Metalink help us into the Note:179466.1
The restrictions that prevent snapshots from being fast refreshed depend on
the version of Oracle being used, a full list of these by version is included
in section 3. In all cases the snapshot defining query should:
- refer to fully qualified table names rather than to partial table names.
- refer to remote tables only, not to remote master views or synonyms.
- not generate context sensitive data. For example, do not create a simple
snapshot with a query that uses the SQL functions :SYSDATE, UID or USER.

DML on materialized view

Hi,
I generated materialized view and will maintain data on it when I run delete statement that show below error
ORA-01732: data manipulation operation not legal on this view
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Regards,
Hiko

taohiko wrote:
There have 8 tables but have only one table that have date/time column and others tables will use primary key from first table relate to data.
And source tables have total records around 300 million records but I want 2 months that around 90 million records.
So I plan to delete data every days that older than 2 months and delete others table with relation by primary from first table.
Can I do? and How to do that?
Regards,
HikoHi,
No you cannot delete the data from materialized view if the view is complex and does not statisfy some basic rules.
Even if you satisfy some of the basic rules still the thing/expectation you have with your MV is not provided by Oracle. If you delete any data from MV, it would be deleted from base table also.
Work around and a better implementation would be
Just include in your create mv a where clause stating
date/time column > trunc(sysdate)-60This would take care of all the other tables data also if they are joined with the main table.
Regards
Anurag

To increase performance of refresh of Materialized View

Dear Members,
I have a set of 231 Materialized Views on a remote database from which I am refreshing data through materialized views. I.e. I have 231 materialized views which are directly copying data from the source views into our internal databases. (basically select column1, column2.... from viewname@dblinkname) There are no where clauses in any of the tables. The refreshes take around 4 hours to run. They either get fast refreshed or complete refresh. It's an on-demand type of refresh.
Could anyone give me suggestions of improving the performance of these refreshes? I would appreciate some guidance in this case.
Kind Regards,
Suhas

Hi Suhas,
If you are asking about Coherence database integration, you could start here ...
http://coherence.oracle.com/display/COH34UG/Read-Through,+Write-Through,+Write-Behind+and+Refresh-Ahead+Caching
Thanks

Regarding Materialized view

Hi all,
I have two database .there is one table in first database.I want to synchronize this table with second database. for that i have created materialized view but when i am create that materialized view it gives following error
ORA-12054: cannot set the ON COMMIT refresh attribute for the materialized view
I m access table from first table to second database by database link.
How can resolve this error? Kindly give suggestion.
Thanks in advance.

From the document.
Refresh Materialized Views
Oracle maintains the data in materialized views by refreshing them after changes are made to their master tables. The refresh method can be incremental (fast refresh) or complete. For materialized views that use the fast refresh method, a materialized view log or direct loader log keeps a record of changes to the master tables.
Materialized views can be refreshed either on demand or at regular time intervals. Alternatively, materialized views in the same database as their master tables can be refreshed whenever a transaction commits its changes to the master tables.

How to store context data in XML file in Webdynpro

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i have one typical requirement as follows.
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is there any one did this functionality then it is great help to me if they share?
Thanks
Sunil

Hi,
In WD4A
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Regards
Lekha

Performance issue accessing Materialized Views

Hi All
I am extracting source data from Materialized View through DBLink which is having record count of 1500000 rows.
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regards
Gourisankar

Hi,
I take it the simple 'Select from "materialized view' doesn't take this long. This could be down to the issue when issuing an 'INSERT' statement using a database link, even if you use the Optimizer hint 'DRIVING_SITE' does not help. The problem is that when issuing an INSERT statement using a DB LINK the filtering of records does not happen on the far side of the link. All the data is moved across the link to the target db, and then filtered etc.
One way to get round this is to use a pipelined function to run your select to get your values, then call the pipeline function via ODI.
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Bos

Data for Classification View in Material Master

Dear all,
Can someone tell where the data for classification view is stored ??
We are running a BDC and need to check whether classification view is maintained or not ??
Thanks in Advance
Regards,
Vivek K

Hi,
Check the table MARA, there is a Field VPSTA. in this field the Material views will be stores with single charecters. so check for the Clasification view charecter
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Work scheduling                A
Accounting                     B
<b>Classification                 C</b>
MRP                            D
Purchasing                     E
Production resources/tools     F
Costing                        G
Basic data                     K
Storage                        L
Forecasting                    P
Quality management             Q
Warehouse management           S
Sales                          V
Plant stocks                   X
Storage location stocks        Z
Regards
Sudheer
Message was edited by:
        Sudheer Junnuthula

Refresh/Update data in a materialized view

Hi,
I have question about the data in a materialized view and how it is refreshed. My mat view has all my dimension-ids and my (for my specialize needs) aggregated measures from my fact table. I used the mat view wizard to create my view - which works perfectly. But now I wonder if I have to create some sort of mapping(?) or some sort of trigger to refresh the data in the mat view. Or is the data automatically refreshed when I start my fact table mappings. I use OWB 11gR2
thx

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Cheers
David

The data of my materialized view....in the while

Hello
We have problems with materialized views
We have one wich re-build each a short period of time
¿Can i avoid the data to dissapear in the time process of refresh?
Is so annoing to our clients to see that "from time to time" the data just dissapear for one period of time -the time while the materialized view is refreshing-
Thank you in advance
Bruno. Madrid. Spain

> Is so annoing to our clients to see that "from time to time" the data just dissapear for
one period of time -the time while the materialized view is refreshing-
Have a similar problem. And dealing with large data volumes that makes the DELETE of the MV a very undesirable feature. Not as much a the resource footprint required, but the time it takes to do this - and the very tight processing windows that exist.
The solution is a self-rolled and very likely not ideal for most - but it works well enough for us in production.
No MV. Create a partition table. Create a staging table. Do a manual "full refresh" of the staging table (TRUNCATE and direct path INSERT). Follow this by a partition exchange with the partition table (no validation and including indexes). The result is that the data is replaced in the partitioned table within a second - no long running and expensive DELETE. End-users not effected by having a truncate pulling the data from beneath their reports.

Exporting data from a materialized view in Oracle 10g

Can anybody tell me how to export data to a remote server and import data in that remote server without using ftp utility. Actually I want to export the data from a materialized view to the remote server and import the same in the remote server.
If everything works well, I'll put the exporting and importing in a cronjob.
Please let me know how can I do that if that's possible .
Any reply would be appreciated.
Thanks.

Here is what I'm trying to do.
I created materialized views using multiple base tables in my local server and the base tables got populated using a long process.
Now I want to copy those data alone to some remote server since it doesn't have any base tables in it. For now, the remote server should depends on the localserver's data. I'm going to use the remote server's data for some testing purposes.
I know it is easy to create mat.views in the remote server but it doesn't have I don't want to do that now. I just want to copy the snapshots from my local server to the remote server.
Please let me know how to do that.
Thanks.

How do I figure where is the data in a materialized view coming from

Hi: when I run select NAME, OWNER from dba_mview_refresh_times, I see a number of materialized views. How do I find more details about this view i.e where is the data coming from and which fields. The source table that is in another database changed. But the view on my database where the materialized view exist has not changed. I want to confirm from where is data coming in this view
TIA
Ravi

SQL> select * from dict where table_name like 'ALL%MVIEW%'
TABLE_NAME                     COMMENTS
ALL_BASE_TABLE_MVIEWS          All materialized views with log(s) in the database that the user can s
                               ee
ALL_MVIEWS                     All materialized views in the database
ALL_MVIEW_AGGREGATES           Description of the materialized view aggregates accessible to the user
ALL_MVIEW_ANALYSIS             Description of the materialized views accessible to the user
ALL_MVIEW_COMMENTS             Comments on materialized views accessible to the user
ALL_MVIEW_DETAIL_PARTITION     Freshness information of all PCT materialized views in the database
ALL_MVIEW_DETAIL_RELATIONS     Description of the materialized view detail tables accessible to the u
                               ser
ALL_MVIEW_DETAIL_SUBPARTITION Freshness information of all PCT materialized views in the database
ALL_MVIEW_JOINS                Description of a join between two columns in the
                               WHERE clause of a materialized view accessible to the user
ALL_MVIEW_KEYS                 Description of the columns that appear in the GROUP BY
                               list of a materialized view accessible to the user
ALL_MVIEW_LOGS                 All materialized view logs in the database that the user can see
ALL_MVIEW_REFRESH_TIMES        Materialized views and their last refresh times for each master table
                                that the user can look at
ALL_REGISTERED_MVIEWS          Remote materialized views of local tables that the user can see
13 rows selected.

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.
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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.
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Store Previous Data in Materialized Views

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