Materialized View Stalesness Unusable

Hi,
I have a situation where a materialized view runs forever in SQL developer and doesn't comeback with a success message. I checked the properties of this Mview and it needed compiling (which i did). Post which the re run performance still doesn't improve. There's another parameter STALENESS which is currently set to UNUSABLE. I have been browsing web but couldn't find much that can help getting the mview of of unusable state.
Could you guys please answer some of my quesiton:
1) Is there a way to get the mview out of unusable state without having to drop it and rebuild?
2) Why would my Mview be running forever and not coming back with any success/failure message?
Note: This mview has dependencies on multiple dimension and fact tables.
Thanks.
Regards
Akshay

You might want to refer to the "Managing Materialized Views" chapter of the Oracle Tuning Guide, and the "Advanced Materialized Views" chapter in the data warehousing guide.
Are you creating materialized view logs and performing a fast (or forced) refresh? The logs can save considerable time as they record changes to the base data, and can be used for fast refreshes. A forced refresh will defer to a fast refresh when it can, or do a full refresh when it must.
Are you taking advantage of partitions?
Look for bottlenecks in your query using the tools already suggested.
You might need to drop and recreate the materialized view if its based on a prebuilt table that was never refreshed.

Similar Messages

Materialized view showing red cross in front of it in SQL developer

we created a materialized view in oracle database,it works fine, and other views that select on it return results and work fine too. But it has a red cross in front of it in oracle developer.
I then refresh the view, or recreate the view, it shows green, but after a while when I come back, the red cross show up again.
What does it mean, any error message we can find?
Thanks

878566 wrote:
we created a materialized view in oracle database,it works fine, and other views that select on it return results and work fine too. But it has a red cross in front of it in oracle developer.
I then refresh the view, or recreate the view, it shows green, but after a while when I come back, the red cross show up again.
What does it mean, any error message we can find?
It means your system is working NORMALLY! There is no 'error message' to find because there is no error. What you describe is EXACTLY how MVs are designed to work.
It is NORMAL for MVs to be, and to become, invalid, especially if there refresh setting is ON DEMAND. Don't confuse 'validity' with 'staleness'; they are very different things.
See the section 'Invalidating Materialized Views' in the Data Warehousing Guide'
http://docs.oracle.com/cd/B28359_01/server.111/b28313/advmv.htm#i1007082
Invalidating Materialized Views
Dependencies related to materialized views are automatically maintained to ensure correct operation. When a materialized view is created, the materialized view depends on the detail tables referenced in its definition. Any DML operation, such as an INSERT, or DELETE, UPDATE, or DDL operation on any dependency in the materialized view will cause it to become invalid. To revalidate a materialized view, use the ALTER MATERIALIZED VIEW COMPILE statement.
A materialized view is automatically revalidated when it is referenced. In many cases, the materialized view will be successfully and transparently revalidated. However, if a column has been dropped in a table referenced by a materialized view or the owner of the materialized view did not have one of the query rewrite privileges and that privilege has now been granted to the owner, you should use the following statement to revalidate the materialized view:
ALTER MATERIALIZED VIEW mview_name COMPILE;
The state of a materialized view can be checked by querying the data dictionary views USER_MVIEWS or ALL_MVIEWS. The column STALENESS will show one of the values FRESH, STALE, UNUSABLE, UNKNOWN, UNDEFINED, or NEEDS_COMPILE to indicate whether the materialized view can be used. The state is maintained automatically. However, if the staleness of a materialized view is marked as NEEDS_COMPILE, you could issue an ALTER MATERIALIZED VIEW ... COMPILE statement to validate the materialized view and get the correct staleness state. If the state of a materialized view is UNUSABLE, you must perform a complete refresh to bring the materialized view back to the FRESH state. If the materialized view is based on a prebuilt table that you never refresh, you will need to drop and re-create the materialized view.
As the doc states Oracle will normally 'revalidate' an MV when it is referenced. You can do this manually by using 'ALTER . . . COMPILE'. For an ON DEMAND MV compiling it will NOT alter the contents of the MV - it may stil be STALE.
You don't need to REFRESH or recreate the MV to make it valid; just recompile it. If it doesn't become VALID after you compile it then there is usually an issue with one of the dependent objects that you need to resolve.

How to get Materialized View to ignore unused columns in source table

When updating a column in a source table, records are generated in the corresponding materialized view log table. This happens even if the column being updated is not used in any MV that references the source table. That could be OK, so long as those updates are ignored. However they are not ignored, so when the MV is fast refreshed, I find it can take over a minute, even though no changes are required or made. Is there some way of configuring the materialized view log such that the materialized view refresh ignores these updates ?
So for examle if I have table TEST:
CREATE table test (
d_id NUMBER(10) PRIMARY KEY,
d_name VARCHAR2(100),
d_desc VARCHAR2(256)
This has an MV log MLOG$_TEST:
CREATE MATERIALIZED VIEW LOG ON TEST with rowid, sequence, primary key;
CREATE MATERIALIZED VIEW test_mv
refresh fast on demand
as
select d_id, d_name
from test;
INSERT 200,000 records
exec dbms_mview.refresh('TEST_MV','f');
update test set d_desc = upper(d_desc) ;
exec dbms_mview.refresh('TEST_MV','f'); -- This takes 37 seconds, yet no changes are required.
Oracle 10g/11g

I would love to hear a positive answer to this question - I have the exact same issue :-)
In the "old" days (version 8 I think it was) populating the materialized view logs was done by Oracle auto-creating triggers on the base table. A "trick" could then make that trigger become "FOR UPDATE OF <used_column_list>". Now-a-days it has been internalized so such "triggers" are not visible and modifiable by us mere mortals.
I have not found a way to explicitly tell Oracle "only populate MV log for updates of these columns." I think the underlying reason is that the MV log potentially could be used for several different materialized views at possibly several different target databases. So to be safe that the MV log can be used for any MV created in the future - Oracle always populates MV log at any update (I think.)
One way around the problem is to migrate to STREAMS replication rather than materialized views - but it seems to me like swatting a fly with a bowling ball...
One thing to be aware of: Once the MV log has been "bloated" with a lot of unneccessary logging, you may perhaps see that all your FAST REFRESHes afterwards becomes slow - even after the one that checked all the 200000 unneccessary updates. We have seen that it can happen that Oracle decides on full table scanning the MV log when it does a fast refresh - which usually makes sense. But after a "bloat" has happened, the high water mark of the MV log is now unnaturally high, which can make the full table scan slow by scanning a lot of empty blocks.
We have a nightly job that checks each MV log if it is empty. If it is empty, it locks the MV log and locks the base table, checks for emptiness again, and truncates the MV log if it is still empty, before finally unlocking the tables. That way if an update during the day has happened to bloat the MV log, all the empty space in the MV log will be reclaimed at night.
But I hope someone can answer both you and me with a better solution ;-)

Peformance on complete refresh of a Materialized View

We are currently doing a complete refresh of a materialized view (35 mil rows) on a monthly basis. My question is would it be faster to disable all the indexes prior to refresh? if so, should we enable the indexes or simply rebuild and which would be faster? Below is the package we are calling to refresh the MV. Also, our platform is Oracle 11g1 Rac on Solaris 10. Thanks.
DBMS_MVIEW.REFRESH(MVIEW_NAME, 'C', ATOMIC_REFRESH => FALSE, PARALLELISM=>16);

Trace it and see.
With ATOMIC_REFRESH set to FALSE, Oracle would be doing a TRUNCATE. See if it does a Direct Path Insert. (It should be doing so).
In which case, Index maintenance is deferred to the end.
Yet, Oracle builds "temporary" index segments when doing the insert and merges them later.
You might still get a performance benefit from setting the indexes to UNUSABLE (or DROPping them) and then doing a REBUID/CREATE with NOLOGGING and a different degree of Parallelism.
You'd have to test it yourself and see what the difference is.
Hemant K Chitale

About Refresh Error In Materialized view

hi
i have
Oracle 9.2.0.1 at the windows server 2003
i have created some materialized view to use in my one web application running on tomcat
i have scheduling for refresh it using refresh utility available in oracle materialized view snapshot refresh
but when its try to run state of refresh become unusable and table according to it
remains empty
when i try to do it manually it gives error log
Ora-12008 error in materialized view refresh path
ora-01114 io error writing block to file 201(block #2621321)
ora-27069 skgfdisp:attmempt to do i/o beyond the range of file
osd-04026 invalid parameter passed(OS 2621327)
ora-01114 io error writing block to file 201(block#2621321)
ora-27069 skgfdisp:attempt do i/o beyond the range of the file
osd-04026 invalid parameter passed (OS 2621327)
ora 06512 at "SYS.DBMS_SNAPSHOt",line 794
ora 06512 at "SYS.DBMS_SNAPSHOt", line 851
ora 06512 at "SYS.DBMS_SNAPSHOt", line 832
ora 06512 at line 2
even i could not understand this error
one strange thing in this when i restart my server and try to refresh
it is going to be refresh
please help me

I suspect one of your datafiles has exceeded the 4Gb windows limit. Your tablespace has probably been set to autoextend and this has created the problem. I am not sure what you can do at this point apart from recover from backup. I would open a TAR with Oracle Support as soon as possible to try and resolve this issue.
Please note: This forum is for OLAP issues only. If you need more information I would try posting on the database forum.
Keith Laker
Oracle EMEA Consulting
OLAP Blog: http://oracleOLAP.blogspot.com/
OLAP Wiki: http://wiki.oracle.com/page/Oracle+OLAP+Option
DM Blog: http://oracledmt.blogspot.com/
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OWB Wiki : http://wiki.oracle.com/page/Oracle+Warehouse+Builder
DW on OTN : http://www.oracle.com/technology/products/bi/db/11g/index.html

Create Materialized View Failure

I'm trying to create a materialized view on a database on my local laptop, and when I execute the create it fails with the following error: ORA-06550: line 1, column 60:
PLS-00103: Encountered the symbol ".16" when expecting one of the following: . ( @ ; with the table name highlighted.
CREATE MATERIALIZED VIEW Schema.MV (col1,
col2,)
BUILD IMMEDIATE
REFRESH Complete ON DEMAND
WITH PRIMARY KEY
AS
select EXTRACTVALUE (rawxml, '/Test.class/@ID') AS col1,
EXTRACTVALUE (rawxml, '/test.class/test.attribute.name') AS col2,
from RAWXML
where Type = 'test.classvalue';
The query on its own though executes fine.
select EXTRACTVALUE (rawxml, '/Test.class/@ID') AS col1,
EXTRACTVALUE (rawxml, '/test.class/test.attribute.name') AS col2,
from RAWXML
where Type = 'test.classvalue';
Is there something wrong with the table setup? I have tried creating a public synonym and still the error comes up.

Thanks for the response Hemant.
All the source tables are in a different schema from the MVs.
p_mv_refersh is in the same schema as the mviews (uimviews).
I've tried dbms_mview.refresh before in a different situation. However, here I need to make sure the snap is consistent so I am using dbms_refresh. I prefer dbms_mviews simply because of the ability to set atomic_refresh=false so I can take advantage of the trunc/append. I wrote the proc so I could take advantage of the consisetncy feature and mimin an atomic refresh. The proc - truncates the tables, sets the indexes unusable, calls dbms_refresh to get a consistent snap then rebuild the indexes in paralell and, finally, sets the degree back to 1 for the indexes. ....whew....! It works great if I can just figure out why the package won't execute.
Any other thoughts/suggestions? If I revert to using dbms_mviews the proc won't be necessary. However, I would like to avoid that if possible (for the above reason).
Thanks....

Usuability of materialized views

Hi ,
How can i exactly tell whether a Mview can really be used ?
i.e the compile_state --> VALID/INVALID
staleness--> FRESH, STALE, UNUSABLE, UNKNOWN, or UNDEFINED
should i be checking the compile_state or the staleness and if it's staleness column then what will indicate that something is wrong with this MV and needs to be re-created ?
pls advise
tks & rgds

Hi,
For a Materialized View to be used with Query Rewrite - the compile state should be "VALID".
As for the "STALENESS" value - It depends on the session settings of the client whose query is a candidate to use the Materialized View (for Query Rewrite). The client session parameter "query_rewrite_integrity" determines what staleness a Materialized View can have and still be used for Query Rewrite.
For query_rewrite_integrity = ENFORCED - only a staleness value of "FRESH" can be used.
For query_rewrite_integrity = TRUSTED - staleness values of "FRESH" and "UNKNOWN" are ok.
For query_rewrite_integrity = STALE_TOLERATED - staleness values of "FRESH", "STALE", and "UNKNOWN" are valid for Query Rewrite - "UNUSABLE" is not - and I have no clue for "UNDEFINED".
Also - you want to make sure that the client's session parameter "query_rewrite_enabled" is equal to "TRUE" or "FORCE" for Query Rewrite to work. A setting of TRUE means that the CBO will compare the cost of querying the base tables to querying the Materialized View - and choose the "cheaper" plan. A setting of FORCE means that the CBO will compare the costs of querying any valid Materialized View suitable for rewrite for the issued query - then choose the cheapest one. If you absolutely don't want base tables to be queried if a query is eligible for rewrite - set this to FORCE.
Hope this helps - good luck.

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

MVs have properties for refresh - you an refresh based on schedules or when dependent data is committed or manually.
Cheers
David

How can I fast refresh the materialized view !!

I created a MV base on some tables in order to improve the querey speed.
but the mv I have created falied to refresh fast.
because there are two same table in the from clause:
jcdm jc1,jcdm jc2
create materialized view temp_mv
nologging
pctfree 0
storage (initial 2048k next 2048k pctincrease 0)
parallel
build immediate
refresh force
on demand
as
select
TAB_GSHX.rowid hx_rid,
TAB_GSHD.rowid hd_rid ,
JC1.rowid jc1_rid ,
JC2.rowid jc2_rid ,
YSHD_ID     HXID,
JC1.JCDM     QFD,
JC2.JCDM     JLD
FROM
TAB_GSHX,
TAB_GSHD,
jCDM JC1,
JCDM JC2
WHERE
YSHD_ID=YSHX_ID
AND YSHD_QFD=JC1.JBJC_ID
AND YSHD_JLD=JC2.JBJC_ID
AND TO_CHAR(YSHX_time,'YYYYMMDD')='20030101'
the column msgtxt of the table MV_CAPABILITIES_TABLE is :
"the multiple instances of the same table or view" and " one or more joins present in mv".
How can I succeed in fast refresh the above temp_mv!!!
thanks.

lianjun,
When you are using Oracle9i there is a procedure which can help you setup the materialized view. If some option isn't working it gives you hint why it doesn't work.
The procedure is dbms_mview.explain_mview.
Take a look at the documentation how to use it. (In the Oracle9i DWH guide the package is explained.)
Hope this helps
With kind regards,
Bas Roelands

Materialized View to run only once in a year...

Hi everybody...
I want to create a materialized view which will run only once in a year and specifically some minutes after 00:00 a.m. on new year's day,
so i created the following:
CREATE MATERIALIZED VIEW <mv_name>
BUILD IMMEDIATE
REFRESH START WITH TO_DATE('01/01/2007 00:15:00','DD/MM/RRRR HH24:MI:SS')
NEXT SYSDATE+366
I have two notes:
1) how to declare the refresh to be done the first new year's day after the day it'll be created , i mean not static date (01/01/2007)
2)some years are leap and some are not , so in order to run every new year's day how should i transform the above..????
3)is there any view which displays the next run of a materialized view..???
the view DBA_MV_REFRESH_TIMES displays the last refresh of mv's...
I use Oracle 10.2.0.1 on XP ...
Thanks , a lot
Simon

1).
use the expression that evaluates to next january first.
SQL> select sysdate, add_months(trunc(sysdate, 'yyyy'), 12) from dual ;
SYSDATE ADD_MONTHS(
19-JUN-2006 01-JAN-2007
1 row selected.
SQL>2). for this also use the same expression that will evaluate to the january first of the year after that.

Is it possible to refresh the table from a Materialized view

Hi,
Is it possible to update the underlying table on which a Materialized view is created when some changes in a Materialized view is done.Is this reverse compatibility possible in Materialized View?
Thanks in Advance,
V.Dennis

If you created the materialized view as UPDATEABLE then changes to it should automatically be relected in the underlying table. If this is not occurring I suggest you check the replication jobs. You probably have a stack of errors in DEFERROR.
Cheers, APC

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.

Issue with creation of a materialized view

Hi,
I have a SQL query that works fine.
But when I create a materialized view using the query, a few columns in the MV do not get populated at all.
What could be the issue here?
regards
Prem

Hi,
Thanks for the reply. Here is the code.
CREATE MATERIALIZED VIEW EDW.MV_OPPTY_ACTIVITY_AGG
TABLESPACE EDW_DIM_DAT
NOCACHE
LOGGING
NOCOMPRESS
NOPARALLEL
BUILD IMMEDIATE
REFRESH COMPLETE ON DEMAND
WITH PRIMARY KEY
AS
select
OPPTY_ID OPPTY_ID,
OPPORTUNITY_KEY OPPORTUNITY_KEY,
oppty_number oppty_number ,
SALES_CONSULTANT_HIST_KEY SALES_CONSULTANT_HIST_KEY ,
company_add_source_key company_add_source_key,
SALES_CONSULTANT_ID SALES_CONSULTANT_ID,
ACTIVITY_TYPE ACTIVITY_TYPE ,
activity_DATE activity_DATE ,
LAST_MODIFIED_DATE LAST_MODIFIED_DATE ,
CUSTOMER_FLAG CUSTOMER_FLAG,
SALES_EMPLOYEE_HIST_KEY,
milestone_KEY,
oppty_milestone_name_hist stage_name,
oppty_milestone_id_hist stage_id,
milestone_prob prob_to_close,
start_date oppty_start_date,
oppty_close_date oppty_close_date,
end_date oppty_end_date,
sum(DURATION) TOTAL_DURATION,
sum (CASE WHEN ACTIVITY_type IN ('CU14', 'CU15', 'CU16', 'CU17',
'CU18', 'CU19', 'CU20', 'CU21') THEN DURATION ELSE 0 END ) CQM_DURATION,
sum (CASE WHEN ACTIVITY_type = 'CU01' THEN DURATION ELSE 0 END ) TRADE_SEM_DURATION,
sum( CASE WHEN ACTIVITY_type = 'CU02' THEN DURATION ELSE 0 END ) RFP_RFI_DURATION,
sum( CASE WHEN ACTIVITY_type = 'CU03' THEN DURATION ELSE 0 END ) INFO_GATH_DURATION,
sum( CASE WHEN ACTIVITY_type = 'CU04' THEN DURATION ELSE 0 END ) PREP_DURATION,
sum( CASE WHEN ACTIVITY_type = 'CU05' THEN DURATION ELSE 0 END ) PRES_DEMO_DURATION,
sum( CASE WHEN ACTIVITY_type = 'CU06' THEN DURATION ELSE 0 END ) POC_DURATION,
sum ( CASE WHEN ACTIVITY_type = 'CU07' THEN DURATION ELSE 0 END ) PRE_CUST_SUPP_DURATION,
sum( CASE WHEN ACTIVITY_type = 'CU08' THEN DURATION ELSE 0 END ) POST_CUST_SUPP_DURATION,
sum( CASE WHEN ACTIVITY_type = 'CU09' THEN DURATION ELSE 0 END ) PARTNER_SUPP_DURATION,
sum( CASE WHEN ACTIVITY_type = 'CU10' THEN DURATION ELSE 0 END ) TRAVEL_DURATION,
sum( CASE WHEN ACTIVITY_type = 'CU11' THEN DURATION ELSE 0 END ) KEYCODES_DURATION,
sum( CASE WHEN ACTIVITY_type = 'CU12' THEN DURATION ELSE 0 END ) SI_SUPP_DURATION,
sum ( CASE WHEN ACTIVITY_type = 'CU13' THEN DURATION ELSE 0 END ) CHANNEL_SUPP_DURATION,
sum( CASE WHEN ACTIVITY_type = 'CU23' THEN DURATION ELSE 0 END ) MIGRATION_DURATION ,
max(LICENSE_USD) LICENSE_USD ,
MAX(LICENSE_LOCAL) LICENSE_LOCAL,
MAX(maintAINANCE_usd) maintAINANCE_usd,
MAX(maintAINANCE_LOCAL) maintAINANCE_LOCAL,
MAX(TRAINING_USD) training_usd,
MAX(TRAINING_LOCAL) training_LOCAL,
MAX(CONSULTING_USD) consulting_usd,
MAX(CONSULTING_LOCAL) consulting_LOCAL,
MAX(RENEWALS_USD) renewals_usd ,
MAX(RENEWAL_local) RENEWAL_local,
max(LOBANALYTICS2_LOCAL) epm_local,
max(LOBDATAINTEGRATION2_LOCAL) eim_local,
max(IDD_AMOUNT_LOCAL) idd_local,
max(ONDEMAND_AMOUNT_LOCAL) ondemand_local,
max(LOBANALYTICS2_usd) epm_usd,
max(LOBDATAINTEGRATION2_usd) eim_usd,
max(IDD_AMOUNT_usd) idd_usd,
max(ONDEMAND_AMOUNT_usd) ondemand_usd
FROM edw.sales_consulting_activity_fct t1 ,
select
o.oppty_id_number,
o.oppty_id,
O.OPPORTUNITY_KEY,
LICENSE_USD LICENSE_USD ,
LICENSE_LOCAL LICENSE_LOCAL,
o.FYM_USD maintAINANCE_usd,
o.FYM_LOCAL maintAINANCE_LOCAL,
o.TRAINING_USD training_usd,
o.TRAINING_LOCAL training_LOCAL,
o.CONSULTING_USD consulting_usd,
o.CONSULTING_LOCAL consulting_LOCAL,
o.RENEWAL_USD renewals_usd ,
o.RENEWAL_local RENEWAL_local ,
o.LOBANALYTICS2_LOCAL,
o.LOBANALYTICS2_usd,
o.LOBDATAINTEGRATION2_LOCAL,
o.IDD_AMOUNT_LOCAL,
o.ONDEMAND_AMOUNT_LOCAL,
o.LOBDATAINTEGRATION2_usd,
o.IDD_AMOUNT_usd,
o.ONDEMAND_AMOUNT_usd
from edw.opportunity_hist_fact o
where o.SOURCE_SYSTEM='SFDC'
and upper(status)='ACTIVE'
and o.last_modified_date = (select max(last_modified_date )from edw.opportunity_hist_fact o2 where o.opportunity_key = o2.opportunity_key))T2,
( Select activity_key,OPPTY_ID_NUMBER, MIL.milestone_KEY,MIL.milestone_name oppty_milestone_name_hist,milestone_id
oppty_milestone_id_hist, milestone_prob,start_date,oppty_close_date,end_date FROM
EDW.opportunity_hist_fact OPP,
edw.milestone MIL,
edw.sales_consulting_activity_fct act WHERE
ACTIVITY_DATE >=start_date (+) and activity_date <=opp.last_modified_date(+)
and OPP.OPPTY_ID_NUMBER (+) =act.OPPTY_NUMBER
and OPP.milestone_key =MIL.milestone_key(+) ) T3
where t1.oppty_NUMBER (+) =T2.OPPTY_ID_NUMBER
and t1.activity_key=t3.activity_key
--and oppty_number ='279749'
GROUP BY OPPTY_ID,
oppty_number,
OPPORTUNITY_KEY,
SALES_CONSULTANT_HIST_KEY ,
company_add_source_key,
SALES_CONSULTANT_ID,
SALES_EMPLOYEE_HIST_KEY,
ACTIVITY_TYPE ,
ACTIVITY_DATE ,
LAST_MODIFIED_DATE,
CUSTOMER_FLAG,
milestone_KEY,
oppty_milestone_name_hist,
oppty_milestone_id_hist,
milestone_prob,
start_date,
oppty_close_date,
end_date;
Regards,
Prem

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.

Materialized View Stalesness Unusable

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