Replication :: Views Or Streaming
Oct 13, 2008I need to know that what is best approach for replication. Materialized View or Streaming. We have to replicate a subset of database at different nodes.
View 3 RepliesI need to know that what is best approach for replication. Materialized View or Streaming. We have to replicate a subset of database at different nodes.
View 3 Repliesfor following two questions.
1. I have created a materialized view with following syntax in 11g R1 database.
CREATE MATERIALIZED VIEW fr_emp_bonus_record_vw
BUILD IMMEDIATE
REFRESH COMPLETE
START WITH SYSDATE NEXT SYSDATE+1/48
ENABLE QUERY REWRITE AS
SELECT person_id, <columns>
This MV will have around 300K records and this MV will be used in other queries based on person_id. So I have created an index on mv.person_id with following syntax. I have chosen REFRESH COMPLETE, I am assuming that, Oracle truncates this table and recreates it. When it recreates this MV, does it analyze automatically or do I need to do it manually.
CREATE UNIQUE INDEX mv_u1 ON mv(person_id);
2. It takes around 2 minutes to populate 300K. While it is populating the data, if somebody accessing this view or query where this view is being used, are they going to get any error?
Can we use Materialized views in Streams like how we use tables... ?
View 11 Replies View RelatedThere is a database db1 which has user U1 in in it contains T1 as table.
Likely,
There is also another database db2 which also has a user named U2 containing table T2 in it.
Now
I want to use the concept of JOINS and Join Table T1 of database named DB1 and Table T2 of database named DB2 and access from database named DB3 using Materialized View Concept.
what shall i do to access tables of DB1 and DB2 from database DB3 using Materialized View.
I have a view with complex query that have grouping and aggregations in sub-queries.
Now we would like to change it to a materialized view. However, materialized view does not support GROUP BY clause in sub-query. The solution is to create several view for the sub-queries and then create a materialized view based on it. It seems it can work, but I guest every time complete refresh is required.
I have a database link between 2 databases and that works fine. Now the tables of one database are having thier materialized views in the other. The materialized views are not getting refreshed. They hang when i try refreshing them. I have tried everything said on the forums. I changed the job_queue_processes. Also changed the query_reqrite_enabled to true. Still it won't work.
View 1 Replies View RelatedCREATE Materialized View log on t1 with rowid;
CREATE Materialized View log on t2 with rowid;
CREATE Materialized View log on t3 with rowid;
CREATE Materialized View MV_test
BUILD IMMEDIATE
FAST REFRESH ON COMMIT
[code].......
I have created a Materialized View by joining the above 3 tables. The Materialized View logs with ROWID has been created on each of the 3 base tables. One of the base tables has around 160 million rows and i expect the Materialized View to have the same number of rows.
The Materialized View has been built for FAST REFRESH on COMMIT. The SELECT list of the CREATE Materialized View statement includes all the ROWIDS from each base tables for doing the fast refresh.
The DBMS_MVIEW explain view shows that the view is capable of doing fast refresh on any DML. The Materialized View took 3 hrs to get built. I have also created indexes on all the three rowid columns (t1rowid,t2rowid,t3rowid) on the Materialized View.
Now, When i do any update on one of the base table and do a commit,
UPDATE t1 set value=500 where tx_id='1234';
The commit is taking around around 15 minutes. I have generated the trace and had a look at it, and it shows that, to refresh the Materialized View, ORACLE is first deleting that record from the Materialized View and then inserting the new record from the base table to the Materialized View.
This delete done by oracle is being done on the basis of the rowid of the updated record stored on the Materialized View log,
However its not using the index created on the t1rowid of the Materialized View and doing a full scan of the MV and hence the delete is taking a lot of time. The delete statement is using a hint NO_MERGE and HASH_SJ which is causing it to do the full table scan of the MV. why is ORACLE not using the index on the t1rowid column of the MV to do this delete?
Also to do the insert in the MV, its selecting the new changed value from the base tables t1,t2 and t2. Here again its doing a full table scan of the base table t1, rather then using the rowid directly or the index coulmn.which is taking a lot of time.
Any best way to gather statistics on Materialized Views.
View 1 Replies View RelatedI have a Problem regarding Data Replication, I am using Standard Version of Oracle 9i,I am having 5 remote servers , I am replicating the data from all of these servers using Materialized views on a Centralized server , I have created 5 schema for them, there is a application which is Consolidating the Data from all the locations.
When I create materialized views from these Materialized views I am facing problems to Fast refresh them as I am using "Union All" to combine data of all Users (Error is ora -12004) . I would like to know that is there any other way to do this, also I have tried all the ways to solve the problem of Ora-12004.
I have a Materialized view based on 2 views. I modified one column in both the views.Do i need to refresh the Materialized view.
E.g. :
In view1 and view2 i changed column like this
nvl(test.no,'n/a') testdata --changed
nvl(test.id,'n/a') testdata --original
CREATE MATERIALIZED VIEW MV_test
NOCACHE
LOGGING
NOCOMPRESS
NOPARALLEL
BUILD IMMEDIATE
[code].........
while replicating the master site via materialized views, in mViewGroups i issued:
BEGIN
DBMS_REFRESH.MAKE (
name => 'mvadmin.hamza_refg',
list => '',
next_date => SYSDATE,
interval => 'SYSDATE + 1/1440', -- for test purpose i used such a small interval
implicit_destroy => FALSE,
rollback_seg => '',
push_deferred_rpc => TRUE,
refresh_after_errors => FALSE);
END;
in my previous attempt it worked all fine... i had a change in senerio, so i did my replication again from scractch using the same old spool in a new installation but even after 3 tries on replicating from scratch my objects are not getting refreshed automatically. even when i attempt to refresh the group it does not work. it works only when i refresh each of the participating object of the group manually.
I have a table in one database and I want to replicate it in another two databases with materialized views. The refresh may be fast. Is this possible?
View 1 Replies View RelatedWe have some materialized views in our environment which refreshes after every 1 hour. In the same environment, we have some big processes and we do not want the performance of these big processes to get affected because of refreshing these materialized views.
if there is a way to pause the refreshing of materialized views before running the big processes and later after the big processes are completed, then resume the refreshing of the materialized views?
One way I can think of is to drop the materialized views and create the materialized views back.
How to refresh the dependent materialized views in a snapshot group. It refreshes in the order we add the materialized views to snapshot group?
Here below is the scenario.
MATVW_A
CREATE MATERIALIZED VIEW MATVW_A BUILD IMMEDIATE
REFRESH FAST ON COMMIT
AS SELECT * FROM EMP;
MATVW_B
CREATE MATERIALIZED VIEW MATVW_B BUILD IMMEDIATE
REFRESH FAST ON COMMIT
AS SELECT * FROM MATVW_A;
MATVW_C
CREATE MATERIALIZED VIEW MATVW_C BUILD IMMEDIATE
REFRESH FAST ON COMMIT
AS SELECT * FROM MATVW_B;
I created a snapshotgroup SNGRP with all the above materialized views.
DBMS_REFRESH.MAKE(name => 'SNGRP',
tab => 'MATVW_A,MATVW_B,MATVW_C',
next_date => TRUNC(sysdate) + 1,
interval => 'SYSDATE + 1');
The order of refreshing the materialized views would be like first materialized view MATVW_A should get refresh then after MATVW_B,MATVW_C.
As they are dependent views.Is there anyway where we can mention the order of refreshing materialized views in snapshot group.
I have 3 reporting tables with 2.2 million records each being rebuilt nightly. The data is used online 24/7 by users and thus, snapshot tables are being built from the refreshed reporting tables. The current method to do this:
delete from snapshot table;
insert into snapshot table (select * from report table);
<repeat for other 2 tables>
commit;
This seems to me to be resource intense on the system even though the table is defined with nologging option.
Is it better to create a MV (select only with refresh complete on demand)? The query is very simple without joins so it at first seems like overkill. However, I am also seeing that dbms_mview.refresh allows for an atomic option. Thus, if 1 of the 3 MVs fails during refresh all 3 rollback, which is a nice feature.
Are there better ways to replicate a snapshot table that I've missed? Is a delete and insert strategy a bad idea?
I have one question on MVIEWS.....
Where the logs will be logged for all the materialized views transactions (I mean a particular table)?
Is there any Data Dictionary Table were i can find this .
Suppose I have materialized view A,B,C. Now I have a new materialized view D which is created from A,B,C. Can I put D into same refresh group?
I am not sure whether D will be refreshed first before A,B,C, resulting that D do not get any update If that is the case, the result will be wrong
If we cannot use refresh group to update nested materialized view, what should we do?
CREATE MATERIALIZED VIEW LOG ON ABC;
CREATE MATERIALIZED VIEW MV_ABC
REFRESH FAST
START WITH SYSDATE
NEXT SYSDATE+20/(24*60)
FOR UPDATE
AS
SELECT * FROM ABC WHERE TMSTP> SYSDATE-1;
It is working fine. Appended the Query with WHERE clause in MV_ABC MVIEWS.
DROP MATERIALIZED VIEW LOG ON ABC;
DROP MATERIALIZED VIEW MV_ABC;
CREATE MATERIALIZED VIEW LOG ON ABC;
CREATE MATERIALIZED VIEW MV_ABC
REFRESH FAST
START WITH SYSDATE
NEXT SYSDATE+20/(24*60)
FOR UPDATE
AS
SELECT * FROM ABC WHERE TMSTP> SYSDATE-1;
ORA-12013: updatable materialized VIEWS must be simple enough TO DO fast refresh
Is it possible to read streaming continuous binary data from a web site using PL/SQL?
View 8 Replies View RelatedI have requirement where replication should be done between two 11gR2 RAC on Standard edition.I have following queries,1. Does Standard edition support DDL capture?
Im asking this because on
[URL]......
it says "SE1/SE: no capture from redo" what that really mean ??2. Can it be possible to configure capture at schema level and skip only some of the tables / triggers ?
is there some open source or free tool which can graphical display V$ Views. Can TOAD do that in a good maner?
in UNIX there is the "sar" command, but a Java tool "ksar" for displaying the statistics in user friendly fashion.
I have a created a materialized view which is based on a view on remote database. Now how do I refresh the view.
Materialized view is created by
CREATE MATERIALIZED VIEW mv_employee_name
AS SELECT EMPLID, EMPL_NAME
FROM VEMPDATA@REMOTEDB
WHERE REGION = 'US';
I am wondering how the refersh happens or how do I specify the refresh clause.REFRESH FAST option is looking for VIEW LOG on the master table but in this case its a remote view, so I cannot create any object on remote db.
I am removing sal column from table tab_emp; i want to check whether any materialized view or view using this column by querying using data dictionary :- if i use like condition against query column of all_mviews it is throwing error sicne it is long data type. is there a way to search it without creating any function and use it in a query.
View 3 Replies View RelatedI have to convert some existing materialized views (fast refresh) to partition materialized views.
Database version is oracle 10.1.0.4. I have decided to use on prebuilt table option to do the partitioning as it minimizes the time to transfer from the master site.
1) stop replication
1) create interim tables with similar structure as the materialized views
2) transfer all data from the materialized views to the interim tables
4) script out the materialized views structure and add in on prebuilt table option in the scripts
5) drop the materialized views
6) rename the interim tables with the same name as the materialized views
7) run the scripts to create the materialized views with on prebuilt table option
8) refresh the newly created materialized views -> it should take a short time since I am using on prebuilt table option
But I am facing one major issue. That is if I drop the materialized views, the materialized view logs of the master tables are purged. When the materialized views are refreshed fast, there are some data missing. the data that are purged out when the materialized view are dropped.
Do you happen to know other ways that existing materialized views can be converted to partitioned materialized views? Do you have any workaround to prevent the materialized view logs from being purged?
Tape streaming is not happening while performing RMAN tape backup. On investigation, you find that it is not because of the incremental backup or the empty file backup and that RMAN is sending data blocks to the tape drive fast enough.What could be a solution to make tape streaming happen during the backup?
A.Configure backup optimization
B.Configure the channel to increase MAXOPENFILES
C.Configure the channel to increase the capacity with the RATE parameter
D.Configure the channel to adjust the tape buffer size with the BLKSIZE option
Actually am trying to replicate two db servers from one in hong kong and another in china. when am trying to establish the replication, am getting error 'ORA-04052: error occurred when looking up remote object' like this...
but the same way i have tried in my local network, it is working fine.i have tried schema replication through enterprise manager grid control..
what are the recommended network requirements for implementing Oracle Multi Master replication.
View 1 Replies View Relatedi need to set up a central server with all the master tables and two other local database which will hold the updatable materialized view of the master table...the databases must be synchronized with central server..and user will work on the materialized view database...
View 10 Replies View RelatedI want to set up advance replication for 3 master site (multimaster) I created 3 master site named orc1,orc2,orc3 and followed up oracle replication management of API book instruction I created 2 tables(tes1,test2) in hr schema in all 3 master site with the same data. then I created the following steps
1-CONNECT repadmin/repadmin@orc1
2-Create the master group named hr_test_repg
BEGIN
DBMS_REPCAT.CREATE_MASTER_REPGROUP(
gname => 'hr_test_repg');
END;
/
4-add tables test1 and test2 to the group
BEGIN
DBMS_REPCAT.CREATE_MASTER_REPOBJECT(
gname => 'hr_test_repg',
type => 'TABLE',
oname => 'test1',
[code]....
I could create DBMS_REPCAT.GENERATE_REPLICATION_SUPPORT for test2 but not for test1 and it produces error
RROR at line 1:
RA-23309: object hr.test1 of type TABLE exists
RA-06512: at "SYS.DBMS_SYS_ERROR", line 105
RA-06512: at "SYS.DBMS_REPCAT_MAS", line 2552
RA-06512: at "SYS.DBMS_REPCAT", line 562
RA-06512: at line 2
I have one 10g database in other country. I want part of their db (selected tables or tablespaces) and import that data to my 10g DB and i want keep to date this data.
I know two ways
1. Data Pump Imp/Emp via FTP, but i can't send only data that have changed (incremental), i must pumping whole selected part of database (i want only new data from their DB, but consistanse with my DB)
2. RMAN etc. or other archivisation tool, i can do incremental achivisation, but can i send files to another instances (my db) and load only that data? Can i do that with SQL*Loader?