SQL & PL/SQL :: Materialized View Makes System Very Slow?
Apr 15, 2010I have created a MV joining 10 tables with FAST REFRESH ON COMMIT It made my sytem very slow.
View 18 RepliesI have created a MV joining 10 tables with FAST REFRESH ON COMMIT It made my sytem very slow.
View 18 RepliesThe customer moved their database from 10g to a 11gR2 database.They created the MV in the new system and now it takes 26 hours to refresh as opposed to 15 min in the old 10g database.Just looking for a game plan for troubleshooting.
View 8 Replies View RelatedI created a Materialized view using joining of two tables with FAST REFRESH ON COMMIT option. These tables are the main tables of the DB and contains alot of data(about 15 millions of records). two master tables have index but mview doesn't have any indexes. I've thought the entire concept of the fast refresh is that it should be a relatively quick operation but the result showed that DB performance reduced, for example I could insert 900 records per minute thru application into master tables before but now I can just insert about 400 records per hour!.Also, It slows down the select operation, went from 0.11 seconds(with joining two tables) to 33 seconds (in mview)!.
First of all, I considered following possibilities and test them:
1) The most likely solution was that a complete refresh was happening. However, the materialized view refresh was confirmed to be a fast refresh by querying USER_MVIEWS.
2) I checked the query of the materialized view and confirmed that it was a simple select from the master tables without any aggregation or sorting.
3) DBMS_MVIEW.explain_mview was run on the materialized view. MV_CAPABILITIES_TABLE did not reveal any problems.
4) A query of dba_registered_snapshots showed that no other snapshots appeared to be using these logs. So, After each refresh, the records in mview logs were deleting.
As you see, it seems everything is ok, but what was causing this fast refresh to go so slow?
I use oracle 10.2 on Suse Linux enterprise server.
I had to drop the MV with preserve table and rebuilt it after modifcation of materalized table.Before dropping the materialized view metdata was.
CREATE MATERIALIZED VIEW "DM_TGT_SHARED"."EA_MERGED_DATA_MV"
ORGANIZATION HEAP PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT)
TABLESPACE "DM_TGT_SHARED"
BUILD IMMEDIATE
USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255
[code]...
now this view taking an ages to refresh as before , there is a MV log i suspect i did not use "with rowid" clause when rebuilding the materliazed view , how can i add with rowid clause which i reckon will improve the MV refreshment.
can we change the existing materialized view to normal view? if yes how?
View 2 Replies View RelatedI'm trying to create a Materialized View on a remote database from a simple view. The reason is, the data owners don't want to grant explicit tables privileges to external subscribers.
A new schema is created to publish data in the form of a view. I've created mlogs on the master tables, and granted them to the subscriber, but it's still complaining about a missing primary key on the view. A primary key does exist in the master table.
Is there another work around for this situation without having to work inside the data sources' environment?
I have big trouble with some Update query on Oracle 11G.I have a set of tables (5) of identical structures and a view that consists in an UNION ALL of the 5 tables.None of this table contains more than 20 000 rows.Let's call the view V_INTE_NE. Each of the basic table has a PRIMARY KEY defined on 3 NUMBERS(10,0) -> INTE_REF / NE_REF / INSTANCE.
Now, I get 6 rows in another table and I want to update my view from the data of this small table (let's call it SMALL). This table has the 3 columns INTE_REF / NE_REF / INSTANCE.
When I try to join the two tables :
SELECT * FROM T_INTE_NE T2
WHERE EXISTS ( SELECT 1 FROM SMALL T1 WHERE T2.INTE_REF = T1.INTEREF AND T2.NE_REF = T1.NEREF AND T2.INTE_INST = T1.INSTANCE )
I get the 6 lines in 0.037 seconds
When I try to update the view (I have an INSTEAD OF trigger that does nothing (just return for testing even without modifying anything), I execute the following query :
UPDATE T_INTE_NE T2
SET INTE_STATE = -11 WHERE
EXISTS ( SELECT 1 FROM SMALL T1 WHERE T2.INTE_REF = T1.INTEREF AND T2.NE_REF = T1.NEREF AND T2.INTE_INST = T1.INSTANCE )
The 6 rows are updated (at least TRIGGER is called) in 20 seconds.
However, in the execution plan, I can't see where Oracle takes time to achieve the query :
Plan hash value: 907176690
[code]....
Predicate Information (identified by operation id):
2 - access("T2"."INTE_REF"="T1"."INTEREF" AND "T2"."NE_REF"="T1"."NEREF" AND
"T2"."INTE_INST"="T1"."INSTANCE")
Note- dynamic sampling used for this statement (level=2)
Statistics
-----------------------------------------------------------
3 user calls
0 physical read total bytes
0 physical write total bytes
0 spare statistic 3
0 commit cleanout failures: cannot pin
[code]....
I get exactly the same execution plan (when autotrace is ON).Furthermore, if I try to do the same update on each of the basic tables, I get the rows updated instantaneously.
I have a materialized view "pro_mview",I am trying to refresh the MVIEW by using the following statement.
EXEC DBMS_MVIEW.REFRESH('pro_mview','C');
But I am getting the below error.
*
Error at line 1:
ORA-12008: error in materialized view refresh path
ORA-00942: table or view does not exist
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 2256
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 2462
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 2431
ORA-06512: at line 1
I am able to fetch the data from that materialized view(pro_mview).
difference between view and materialized view?
View 1 Replies View Relatedwhat would be the difference between a view and a materialized view? whether DML possible on a view? i think error occurs if DML tried on a view which is a combination of two or more tables, whether DML possible on a materialized view?
View 7 Replies View RelatedI have requirement to create materialized views. The design states to use Complete refresh. Now I am using WITH ROW_ID clause.
1. Question - what are the criteria to decide between WITH PRIMARY KEY & WITH ROW_ID clauses? I referred oracle doc, but couldn't exactly get this.
2. Background - The oracle doc mentions that - Primary key materialized views are the default type of materialized view. The master table must contain an enabled primary key constraint, and the defining query of the materialized view must specify all of the primary key columns directly.
Question - I saw some existing materialized views in my project using WITH PRIMARY KEY clause, but all of the primary key columns are not part of the Select query, but still these views are working fine, how is this possible?
3. Background - The oracle doc mentions that - Rowid materialized views must be based on a single table and cannot contain any of the following:
■Distinct or aggregate functions
■GROUP BY or CONNECT BY clauses
■Subqueries
■Joins
■Set operations
Question - But I have created a Rowid materialized view selecting data from more than one table & defining query involving outer joins. This materialized view got created & getting refreshed (complete refresh). But again this is contradicting with Oracle' statement.
There are some sys views can not found. why?
SQL> connect / as sysdba
Connected.
SQL> show user;
USER is "SYS"
SQL> desc dba_users;
ERROR:
ORA-04043: object dba_users does not exist
There are 2 databases, database A and database B. Database A is Oracle 11.2.0.2 which runs on linux and Database B is Oracle 11.2.0.2 which runs on windows xp machine. In database A, there are 100's of tables which are being updated every 10 minutes or 15 minutes. For reporting purpose, the developer wants to run report for the tables. But since database A is being updated every now and then, generating reports takes almost 15 to 20 minutes. So the reports can be generated in Database B. Once in a day the database B should have the updated data from database A so that the reports can be generated in database B with less time. What could be the best solution for the database B to have the updated data on daily basis from database A in oracle?
View 3 Replies View Relatedi have created FAST refresh materialized view.it is eligible for FAST refresh because when i executed SELECT * FROM USER_MVIEWS i could see FAST_REFRESHABLE=DIRLOAD_DML and STALENESS=STALE and it is not getting refreshed(through DBA_JOBS). Why it is in STALE status and how to resolve it. and one of my materialized views is in NEEDS_COMPILE status
View 3 Replies View RelatedA scheduler job is there to refresh some materialized views. All the views are run under single job name. Some mviews are not refreshing and those are not refreshing in the next run too.if we run those mviews manually then they are working fine from then . after some days those views which i told before are not refreshing and this happens frequently and i check the job_run_details views also and i am not seeing any errors in that.
View 6 Replies View RelatedI need redefine a Materialized View (add some columns). I try it with:
drop materialized view TCPIP preserve table;
ALTER TABLE TCPIP ADD (SUM_IP_OUT_OF_SEQ NUMBER)
/
ALTER TABLE TCPIP ADD (SUM_IP_OUT_OF_SEQ NUMBER)
/
and than create a new MV:
CREATE MATERIALIZED VIEW TCPIP
ON PREBUILT TABLE USING NO INDEX NEVER REFRESH ENABLE QUERY REWRITE as
SELECT ...
But with Oracle error: ORA-12060: shape of prebuilt table does not match definition query
I check the new MV definition, it is contain the 2 added columns.
Why we can create indexes only on materialized view and not on normal views?
View 8 Replies View RelatedCan u explain the syntax of materialized view??????
View 1 Replies View RelatedHow can we find how much space is used by the materialized view.
View 1 Replies View RelatedI have created a Materialized View (MV) and within the MV DDL have included a statement as per below. However, the MV does not seem to be refreshing on a daily basis. I can see the job in dba_jobs table. So the question, is there some system setting i need to execute or create in order for Oracle to know that it needs to run the Job defined in the dba_jobs table on a daily Basis?
View 8 Replies View RelatedI have created materialized view which hold few million records.Should i have to analyze the view and compute the statistics after i create the materialized view?
Also, just in case i need further indexing, should i have to take the statistics for the table again?
I am running into an issue and trying to ascertain issue. Scenario:I have 2 MV creation scripts. The MV is supposed to get populated by connection from schema to another schema USING DB Links.Basically, SAME HOST, SAME RAC DATABASE, just separate schemas. The MV creations are just hanging. I see NO alert log mentions. I ran a SQL trace and yes,
I see: call count cpu elapsed disk query current rows------- ------ -------- ---------- ---------- ---------- ---------- ----------Parse 0 0.00 0.00 0 0 0 0Execute 1011 1.40 73.80 0 0 0 0Fetch 1010 1.08 317.57 0 0 0 1010------- ------ -------- ---------- ---------- ---------- ---------- ----------total 2021 2.49 391.38 0 0 0 1010 Misses in library cache during parse: 0Optimizer mode: ALL_ROWSParsing user id: 109 (recursive depth: 2) Elapsed times include waiting on following events: Event waited on Times Max. Wait Total Waited ---------------------------------------- Waited ---------- ------------ SQL*Net message to dblink 2022 0.00 0.00 SQL*Net message from dblink 2021 0.46 242.58
Understandable, but when I do a selective query, the results come back pretty much within 5 seconds.DB version is 11.2.0.3. Is there a BUG that I should know about?
Here is a snippet:
CREATE MATERIALIZED VIEW "SCHEMA"."MV_NAME_MV" USING INDEX REFRESH COMPLETE ON DEMAND AS (SELECT distinct mapguide_persons(pl.location_code) "FULL_NAME_COSTCENTER",mapguide_jobemp(pl.location_code) "TRUNCNAME_JOB",mapguide_empnum(pl.location_code) "FULLNAME_EMPNUMBER_PHONE",mapguide_english(pl.location_code)
[code]....
we have a materialized view (in Oracle 11g), usually this MV we easily drop and recreate it.
But last few days, i am trying to drop a MV, but running a long time but no result and it keeps running. not dropped also.
Bcos, db performance is good since we tried to a view using script, it is fine. Problem seems only with Materialized view.
where and how to check what is the issue?
some of MVs become invalid (yes, we did app upgrade over the weekend). I looked on every object reference in the MV, all permissions - can't find anything.I dropped MVs and created them no errors. Status changed to VALID. I decided to re-COMPILE them (because I saw public synonyms for MVs as INVALID). After compilation status changed back to INVALID.Oracle 11.2, Solaris 10.
View 2 Replies View RelatedI have got a materialized view which is created over a dblink as below:
CREATE MATERIALIZED VIEW CRIMEREPORTODSV
TABLESPACE ODS_DATA
BUILD IMMEDIATE REFRESH FAST AS
(SELECT * FROM CRIME_INT@CRISP);
This is all fine and works apart from any changes to the source table (CRIME_INT) isn't reflected unless I perform a refresh. Whereas I want any changes to be reflected straight away. I have had to use a Materialized view in this case as one of the columns in the source table is a CLOB and Oracle won't allow creation of a view with a CLOB field over DBLINK.
I created a materialized view which takes around 6 hrs to refresh. way to reduce the refresh time.The query is:
create materialized view ERC_DAILY_DISBURSMENT_MIS_VIEW
refresh complete on demand as
with disb_qur as (select e.account_no,
e.journal_dt,
e.instr_amt disbursed_amt,
[code]....
Pipe Function and Materialized View.
There is a materialized view:
CODECREATE MATERIALIZED VIEW MY_MAT_VIEW NOLOGGING
REFRESH FORCE
START WITH SYSDATE NEXT SYSDATE + 5/24/60
AS
SELECT F1,
F2,
F3
from SOMETAB;
And there is a pipelined function:
CODEDROP TYPE MY_MAT_VIEW_table_type;
DROP TYPE MY_MAT_VIEW_row_type;
CREATE TYPE MY_MAT_VIEW_row_type AS OBJECT
(
F1 number,
F2 varchar2(100),
F3 date
[code].......
I've noticed that when materialized view is near to be refreshed (every 5 minutes) there is some "delay" in getting result sets using this query:
SELECT *
FROM TABLE(FN_GET_MY_MAT_VIEW(100)) a;
And when the refresh is finished the result set returns immediately.
Question.
Is there a way to avoid such "delay" while materialized view is refreshing?
I try to do this:
CREATE MATERIALIZED VIEW MV_NESTED_DATA
NOCACHE
LOGGING
NOCOMPRESS
NOPARALLEL
BUILD IMMEDIATE
USING NO INDEX
REFRESH COMPLETE
ON DEMAND
START WITH ROUND(SYSDATE)
NEXT ROUND(SYSDATE) + 1
WITH ROWID
AS
select NESTED_TABLE_FIELD from MY_TABLE@Y_DB_LINK;
where NESTED_TABLE_FIELD is a nested table stored as T_NESTED_TABLE
And I get the error: ORA-12014: table 'T_NESTED_TABLE' does not contain a primary key constraint
Why should it if I try to create a MV with "WITH ROWID" refresh option and not "WITH PRIMARY KEY" one?
I am new to Oracle and I inherited an existing database. I have a materialized view on a table that uses a materialized view log. I have been asked to see if it is possible to categories the rows by change type (inserted, updated or deleted) and populate another materialized view or table accordingly. If this is possible then how can it be achieved.
View 1 Replies View Related