Materialized view fast refresh option

Dear all,

I have a vision materilized which refreshes every 5 minutes and his works well, but one of the base tables has 300 fields and I need this view refresh only when 3 of the fields of 300 has evolved.

If anyone can help me, I understand that

The script of my VM is:

CREATE MATERIALIZED VIEW SCHEMA1. INVM_TARJETADEBITO_SALDOS_VM

N OCACHE

LOGGING

NOCOMPRESS

NOPARALLEL

BUILD IMMEDIATE

REFRESH FAST START WITH SYSDATE NEXT SYSDATE + 5/1440

WITH THE PRIMARY KEY

SELECT CHAMP_1, CHAMP_2, FIELD_3, FIELD_4

OF SCHEMA1. TABLE_1 has, SCHEMA1. TABLE_2 b

WHERE a.PK_1 = b.PK_1;

Best regards

Diego Nuñez

> but one of the base tables has 300 fields and I need from this point of view, refresh only when 3 of the fields of 300 has evolved.

You cannot set this "restriction". If a row is updated - know if 1 single byte in a column or 300 columns are updated - the line qualifies to be propagated to the MV.

That you can set is * that * columns are replicated in the MV.

For the journal of MV, you can also specify which columns are referenced as columns of filter (with the WITH clause). It is usually of the columns that use the MV and/or is the joining columns for a MV that has a join.

Hemant K Collette

Tags: Database

Refresh Options

When you define a materialized view, you can specify three update options: how to refresh, what kind of update and can trust constraints be used. If not specified, default values are considered as ON DEMAND , FORCE , and ENFORCED forced respectively.

The two execution modes are ON COMMIT and ON DEMAND . According to the materialized view, you create, some options may be unavailable. Update modes are described in table 8-4 .

Table 8-4 Modes of discount

Refresh the Mode	Description
`ON COMMIT`	Refresh product automatically when a transaction which changed one of the paintings of the materialized view's retail is committed. This can be specified as the materialized view is quickly updatable (in other words, no complex). The `ON` `COMMIT` privilege is required to use this mode.
`ON DEMAND`	Refresh occurs when a user manually executes one of the procedures available refresh contained in the `DBMS_MVIEW` package ( `REFRESH` , `REFRESH_ALL_MVIEWS` , `REFRESH_DEPENDENT` ).

http://docs.Oracle.com/CD/B28359_01/server.111/b28313/basicmv.htm#i1006193

materialized view full refresh much slower that recreate
Hello!

We use the view materialized for our DWH, which freshen every day to demand and full. I noticed that after some time refreshing take very long materialized view (1 h), recreating the view materialized and refreshing it at the same time just takes a few minutes. The result is exactly the same thing.
Can someone explain to me why this is the case? And is there a better way to recreate materialized view that copying and running the entire SQL statement?

Thanks for your help!

Edited by: 890408 26 March 2012 23:29
Since 10g or 10 g 2, the default behavior for a refreshment FULL of a MV is DELETE and INSERT.
(In 9i, it was TRUNCATE and INSERT - which was, obviously, faster).
The advantage with the DELETE and INSERT, is that the data are still visible in the MV while it is updating.

See Oracle's Support article:
Refresh complete reading consistency behavior during refresh and refresh complete Performance influenced by the setting of refresh ATOMIC_REFRESH [ID 553464.1]

Hemant K Collette

The Materialized View - ORA-12052: is unable to fast refresh materialized view

Hello
I was hitting my head all day trying to create materialized views. I have made some progress, but have hit a brick wall, unfortunately!
Basically, I have been invited to take a view and see if I can get the benefits of performance by transforming all or part of it in materialized views. Because the underlying tables of the config is updated quite frequently, I want to fast refresh materialized views on commit. However, when I try to create a materialized view containing an outer join in an aggregated materialized view table, I get ORA-12052: is unable to fast refresh materialized view.
I went through the documentation and also Rob van Wijkvery useful series of blogs on the topic (especially http://rwijk.blogspot.co.uk/2009/09/fast-refreshable-materialized-view.html) but have not found anything that matches. Maybe I missed something somewhere along the line, or maybe I'm asking just something completely impossible?
My db is 11.2.0.2.
Here's the test scripts, I've worked with that:
drop materialized view test1_test2_mv;
Drop materialized view test2 journal;
drop table test2;
Drop materialized view test1_mv newspaper;
drop materialized view test1_mv;
Drop materialized view test1 journal;
drop table test1;
create table test1 (identification number,
type varchar2 (10),
number of Val,
update_time date,
constraint t1_pk primary key (id, type, val));

Insert into test1
Select 1, 'a', 1001, sysdate - 10/24 Union double all the
Select 1, 'b', 1003, sysdate - 9/24 Union double all the
Select 1, 'c', 1002, sysdate - 8/24 Union double all the
Select 1, had ', 1004, sysdate - 7/24 Union double all the
Select 1, 'e', 1005, sysdate - 6/24 Union double all the
Select 1, 'c', 1006, sysdate - 5/24 Union double all the
Select 2, 'a', 1002, sysdate - 4/24 Union double all the
Select 2, 'b', 1005, sysdate - 3/24 Union double all the
Select 3, 'a', 1001, sysdate - 2/24 Union double all the
Select 3, 'c', 1006, sysdate - 1/24 Union double all the
Select 3, 'e', 1008, sysdate - 2/24 Union double all the
Select option 4, has ', 1004, sysdate - 3/24 Union double all the
Select 5, 'b', 1002, sysdate - 4/24 Union double all the
Select 5, 'g', 1001, sysdate - 5/24 Union double all the
Select 6, 'h', 1004, sysdate - 6/24 Union double all the
Select 7, 'b', 1007, sysdate - 7/24 Union double all the
Select 7, had ', 1001, sysdate - 8/24 double;
commit;
Select * from test1;

CREATE MATERIALIZED VIEW LOG ON test1
WITH rowid, primary key (update_time)
including the new values;

Test1_mv CREATE MATERIALIZED VIEW
IMMEDIATE CONSTRUCTION
COOL OFF QUICKLY ON COMMIT
Did YOU SELECT id,
MAX (case when type = "there" end of val) THAT col_a,.
MAX (case when type = 'b', then val end) AS col_b,.
MAX (case when type = 'c' then end val) AS col_c,.
MAX (case when type = ' then end of val) AS col_d,
MAX (update_time) AS update_time
OF test1
WHERE TYPE in ('a',
« b »,
« c »,
a ')
GROUP BY id;
CREATE MATERIALIZED VIEW LOG ON test1_mv
WITH rowid
including the new values;

create table test2 (identification number,
col2 number,
COL3 varchar2 (10),
number of COL4,
constraint t2_pk primary key (id));

Insert into test2
Select 1, 1, 'bob', 1 double Union all
Select 2, 1, "sue", 1 double Union all
Select 3, 1, 'tom', 1 double Union all
Select 4, 1, 'jay', 1 double Union all
Select 5, 1, 'art', 1 double Union all
Select 6, 1, 'kay', 1 double Union all
Select 7, 1, 'max', 1 double Union all
Select 8, 1, 'tim', 1 double Union all
Select 9, 1, "liz", 1 from dual;
commit;

CREATE MATERIALIZED VIEW LOG ON test2
WITH rowid, primary key
including the new values;

Test1_test2_mv CREATE MATERIALIZED VIEW
IMMEDIATE CONSTRUCTION
COOL OFF QUICKLY ON COMMIT
LIKE SOME t2.rowid,.
T1.ID,
T1.col_a,
T1.col_b,
T1.col_c,
T1.col_d,
T1.update_time,
T2.col2,
T2. COL3
OF test1_mv t1,.
Test2 t2
WHERE (+) t1.id = t2.id; -symbol of outer join is not correctly displayed on the forums without space, grr!
ORA-12052: is unable to fast refresh materialized view TEST1_TEST2_MV
Y at - it any way I can get the materialized view fast refresh on commit or I asking the impossible?

Add t1.rowid:

SQL > CREATE MATERIALIZED VIEW test1_test2_mv

2 BUILD IMMEDIATE

3 QUICK REFRESH YOU COMMIT

4 AS t2.rowid SELECT rid2,

5 t1.rowid rid1,

6 t1.id

T1.col_a 7,.

T1.col_b 8,.

T1.col_c 9,.

T1.col_d 10,

T1.update_time 11,

T2.col2 12,

13 t2.col3

14 OF test1_mv t1,

15 test2 T2

16 WHERE t1.id = t2.id

17.

Materialized view created.

SQL > select * from test1_test2_mv

2.

RID2 RID1 ID COL_A, COL_B, COL_C COL_D UPDATE_TIME COL2 COL3

------------------ ------------------ ---------- ---------- ---------- ---------- ---------- ------------------- ---------- ----------

AAAYB6AANAAAANDAAA AAAYB/AANAAAAN/AAA 1 1001 1003 1006 1004 25 / 06 / 2014 12:54:16 1 bob

AAAYB6AANAAAANDAAB AAAYB/AANAAAAN/AAB 2 1002 1005 25 / 06 / 2014 1 sue 14:54:16

AAAYB6AANAAAANDAAC AAAYB/AANAAAAN/AAC 3 1001 1006 25 / 06 / 2014 16:54:16 1 tom

AAAYB/AANAAAAN/AAD AAAYB6AANAAAANDAAD 4 1004 25/06/2014 14:54:16 1 jay

AAAYB6AANAAAANDAAE AAAYB / AANAAAAN / AAE 5 1002 2014/06/25 13:54:16 1 art

AAAYB6AANAAAANDAAF AAAYB/AANAAAAN/AAG 7 1007 1009 25 / 06 / 2014 10:54:16 max 1

AAAYB/AANAAAAN/AAH                                                                                                        1 tim

AAAYB/AANAAAAN/AAF                                                                                                        1 kay

AAAYB/AANAAAAN/AAI                                                                                                        1 liz

9 selected lines.

SQL > update of test2

2 set col3 = "fly."

3 where id = 7

6 m

1 line update.

SQL > validation

2.

Validation complete.

SQL > select * from test1_test2_mv

2.

RID2 RID1 ID COL_A, COL_B, COL_C COL_D UPDATE_TIME COL2 COL3

------------------ ------------------ ---------- ---------- ---------- ---------- ---------- ------------------- ---------- ----------

AAAYB6AANAAAANDAAA AAAYB/AANAAAAN/AAA 1 1001 1003 1006 1004 25 / 06 / 2014 12:54:16 1 bob

AAAYB6AANAAAANDAAB AAAYB/AANAAAAN/AAB 2 1002 1005 25 / 06 / 2014 1 sue 14:54:16

AAAYB6AANAAAANDAAC AAAYB/AANAAAAN/AAC 3 1001 1006 25 / 06 / 2014 16:54:16 1 tom

AAAYB/AANAAAAN/AAD AAAYB6AANAAAANDAAD 4 1004 25/06/2014 14:54:16 1 jay

AAAYB6AANAAAANDAAE AAAYB / AANAAAAN / AAE 5 1002 2014/06/25 13:54:16 1 art

AAAYB/AANAAAAN/AAH                                                                                                        1 tim

AAAYB/AANAAAAN/AAF                                                                                                        1 kay

AAAYB/AANAAAAN/AAI                                                                                                        1 liz

AAAYB6AANAAAANDAAF AAAYB/AANAAAAN/AAG 7 1007 1009 25 / 06 / 2014 10:54:16 1 rob

9 selected lines.

You want to capture update dates, with trigger on a view to refresh quickly materialized. But trigger on MV consider inserting and updates are inserts only.

Oracle Database 11 g Enterprise Edition Release 11.2.0.4.0 - 64 bit Production
PL/SQL Release 11.2.0.4.0 - Production
CORE Production 11.2.0.4.0
AMT for Linux: Version 11.2.0.4.0 - Production
NLSRTL Version 11.2.0.4.0 - Production
I create the structure of the table like that.
create table test1 (a primary key, b (2) char number, date c, d varchar2 (10), date of e);
create table test2 (number of ab, cd (2) tank, date of the ef, gh varchar2 (10), date of the ij, kl varchar2 (100));
Create materialized view log on test1;
create materialized view fast refresh test1_v on commit in select * from test1;
I have create a trigger of the sample
CREATE OR REPLACE TRIGGER test1_trig
AFTER INSERT OR UPDATE OR DELETE
ON test1_v
FOR EACH LINE
DECLARE
lr_test2 test2% ROWTYPE;
lv_error VARCHAR2 (4000);
BEGIN
lr_test2. AB: =: NEW.a;
lr_test2. CD: =: NEW.b;
lr_test2. GH: =: NEW.d;
IF THE INSERTION
THEN
lr_test2. EF: = SYSDATE;
lr_test2.IJ: = SYSDATE;
lr_test2.KL: = 'INSERT ';
INSERT INTO test2
VALUES lr_test2;
ELSIF UPDATE
THEN
lr_test2.IJ: = SYSDATE;
lr_test2.KL: = 'UPDATE ';
UPDATE test2 = lr_test2 ab WHERE = LINE: OLD.a;
ELSIF REMOVAL
THEN
DELETE FROM test2
AB = WHERE: old.a;
END IF;
EXCEPTION
WHILE OTHERS
THEN
lv_error: = SQLERRM;
INSERT INTO XXDOMINO_FG_DATA_LOAD_ERROR
VALUES ('test1_trig',
: OLD.a,.
"test1_trig,"
LV_ERROR,
SYSDATE);
COMMIT;
END test1_trig;
/
So, if check you my code,.
When I insert EF = SYSDATE, IJ = SYSDATE.
Update EF is not changed, IJ = SYSDATE.
So I like to capture their insertion and update dates.
But if updates or insert arrives on the materialized table. The trigger themselves as an INSERT only.
So how do you capture the updates?

I use the statemnet with out merger with performance and also able to capture the update dates.

CREATE OR REPLACE TRIGGER test1_trig_merge

AFTER INSERT OR UPDATE OR DELETE

ON test1_v

FOR EACH LINE

DECLARE

lr_test2 test2% ROWTYPE;

lv_error VARCHAR2 (4000);

BEGIN

IF THE REMOVAL

THEN

DELETE FROM test2

AB = WHERE: old.a;

ELSIF INSERTION

THEN

MERGE INTO test2 one

B using (SELECT 1 FROM DUAL)

WE (ab =: new.a)

WHEN MATCHED

THEN

UPDATE the VALUE ab =: NEW.a.

CD =: NEW.b,

GH =: NEW.c

IJ = SYSDATE,

KL = "Update"

AB WHERE =: old.a

WHEN NOT MATCHED

THEN

INSERTING VALUES (: NEW.a,)

: NEW.b,.

: NEW.c.

: NEW.d,.

: NEW.e,.

"INSERT");

END IF;

EXCEPTION

WHILE OTHERS

THEN

lv_error: = SQLERRM;

INSERT INTO XXDOMINO_FG_DATA_LOAD_ERROR

VALUES ('test1_trig',

: OLD.a,.

"test1_trig,"

LV_ERROR,

SYSDATE);

END test1_trig_merge;

/

DISPLAY ERRORS;

Pivot can be used in fast refresh materialized view?

Hi, I have a question about materialized view nested mode fast refresh on Oracle 11 g (It support function of pivot, but oracle 10 g doesn't support).

When I created, he throws "ORA-12015: cannot create a view fast refresh materialized by a complex query.
Then I used dbms_mview.explain_mview to see reason, and it tell me the following
REFRESH_FAST_AFTER_INSERT ' view inline or subquery in LIST not supported for this type of MV.

Can someone help me, any suggestions will be appreciated

create table empX as select * from scott.emp;
alter table empX add constraint PK_empX_empno primary key (empno);

--drop  MATERIALIZED VIEW LOG ON empX;
CREATE MATERIALIZED VIEW LOG ON empX with rowid, sequence(empno);

--drop MATERIALIZED VIEW mv_empX;
CREATE MATERIALIZED VIEW mv_empX
REFRESH FAST START WITH SYSDATE
NEXT  SYSDATE + 1/1440
AS   
  select * from
  (
   select rowid emp_rowid, deptno, job, sal from empX
  )
  PIVOT( max(sal) for job IN ('ANALYST' job1, 'CLERK' job2, 'MANAGER' job3));
 
--select * from mv_capabilities_table
declare
  lv_sqltext varchar2(4000);
begin
  execute immediate 'truncate table mv_capabilities_table';
  lv_sqltext := 'select * from
  (
   select deptno, job, sal from empX
  )
  PIVOT( max(sal) for job IN (''ANALYST'' job1, ''CLERK'' job2, ''MANAGER'' job3))
  ';  
  dbms_mview.explain_mview(lv_sqltext,'nested=>TRUE');
  commit;
end;
/

Let me help you...
I have done following and it run/view updated because I just replaced quickly with a complete word, because there are limitations for quickly updatable views:

SQL> show user;
USER is "SCOTT"
SQL> create table empX as select * from scott.emp;

Table created.

SQL> alter table empX add constraint PK_empX_empno primary key (empno);

Table altered.

SQL>
SQL> --drop  MATERIALIZED VIEW LOG ON empX;
SQL> CREATE MATERIALIZED VIEW LOG ON empX with rowid, sequence(empno);

Materialized view log created.

SQL>
SQL> --drop MATERIALIZED VIEW mv_empX;
SQL> CREATE MATERIALIZED VIEW mv_empX
  2  REFRESH COMPLETE WITH rowid
  3  START WITH sysdate
  4  NEXT  SYSDATE + 1/1440
  5  AS
  6    select * from
  7    (
  8     select rowid emp_rowid, deptno, job, sal from empX
  9    )
 10    PIVOT( max(sal) for job IN ('ANALYST' job1, 'CLERK' job2, 'MANAGER' job3));

Materialized view created.

SQL> select * from mv_empx;

EMP_ROWID              DEPTNO       JOB1       JOB2       JOB3
------------------ ---------- ---------- ---------- ----------
AAAShcAAEAAAATTAAN         10                  1300
AAAShcAAEAAAATTAAE         30
AAAShcAAEAAAATTAAJ         30
AAAShcAAEAAAATTAAC         30
AAAShcAAEAAAATTAAA         20                   800
AAAShcAAEAAAATTAAK         20                  1100
AAAShcAAEAAAATTAAM         20       3000
AAAShcAAEAAAATTAAD         20                             2975
AAAShcAAEAAAATTAAB         30
AAAShcAAEAAAATTAAI         10
AAAShcAAEAAAATTAAL         30                   950

EMP_ROWID              DEPTNO       JOB1       JOB2       JOB3
------------------ ---------- ---------- ---------- ----------
AAAShcAAEAAAATTAAF         30                             2850
AAAShcAAEAAAATTAAG         10                             2450
AAAShcAAEAAAATTAAH         20       3000

14 rows selected.

SQL> begin
  2  dbms_mview.refresh('SCOTT.mv_empx');
  3  end;
  4  /

PL/SQL procedure successfully completed.

SQL> select * from mv_empx;

EMP_ROWID              DEPTNO       JOB1       JOB2       JOB3
------------------ ---------- ---------- ---------- ----------
AAAShcAAEAAAATTAAN         10                  1300
AAAShcAAEAAAATTAAE         30
AAAShcAAEAAAATTAAJ         30
AAAShcAAEAAAATTAAC         30
AAAShcAAEAAAATTAAA         20                   800
AAAShcAAEAAAATTAAK         20                  1100
AAAShcAAEAAAATTAAM         20       3000
AAAShcAAEAAAATTAAD         20                             2975
AAAShcAAEAAAATTAAB         30
AAAShcAAEAAAATTAAI         10
AAAShcAAEAAAATTAAL         30                   950

EMP_ROWID              DEPTNO       JOB1       JOB2       JOB3
------------------ ---------- ---------- ---------- ----------
AAAShcAAEAAAATTAAF         30                             2850
AAAShcAAEAAAATTAAG         10                             2450
AAAShcAAEAAAATTAAH         20       3000

14 rows selected.

SQL>

So, the answer is Yes, we can use Pivot with Materialized view but:
1 MV must be full refresh.
2 oracle version should be 11 g; of course the pivot is available in Oracle 11 g.

If this answers your question, please close the message, otherwise continue.

These links may also be of interest:
http://docs.Oracle.com/CD/B28359_01/server.111/b28313/basicmv.htm#i1007028
http://docs.Oracle.com/CD/B28359_01/server.111/b28313/basicmv.htm#i1007007

http://rwijk.blogspot.in/2009/06/fast-refreshable-MATERIALIZED-view.html

And:

Please see if (Note: 179466.1 - view to fast refresh materialized diagnose ORA-12015 / complex queries) help.

Concerning
Girish Sharma

fast refresh on MATERIALIZED VIEW
Oracle 10 g R2 (10.2.0.5)

Scott.mv_test CREATE MATERIALIZED VIEW
Users TABLESPACE
NOCACHE
LOGGING
NOCOMPRESS
NOPARALLEL
IMMEDIATE CONSTRUCTION
REFRESH THE STRENGTH TO DEMAND
WITH THE PRIMARY KEY
AS
Select...

I this MV, when I do the QUICK refersh as follows, I get the error message

SQL > execute DBMS_MVIEW. REFRESH ('MV_TEST', 'f');
DBMS_MVIEW BEGIN. REFRESH ('MV_TEST', 'f'); END;

*
ERROR on line 1:
ORA-12004: QUICK COOLING can be used to view materialized "SCOTT." "" MV_TEST ".
ORA-06512: at "SYS." DBMS_SNAPSHOT", line 2251
ORA-06512: at "SYS." DBMS_SNAPSHOT", line 2457
ORA-06512: at "SYS." DBMS_SNAPSHOT", line 2426
ORA-06512: at line 1

But it works with full refresh.

Is this planned, any help would be appreciated.

Thank you
```
ORA-12004: REFRESH FAST cannot be used for materialized view "string"."string"
Cause:      The materialized view log does not exist or cannot be used. PCT refresh is also not enabled on the materialized view
Action:      Use just REFRESH, which will reinstantiate the entire table. If a materialized view log exists and the form of the materialized view allows the use of a materialized view log or PCT refresh is possible after a given set of changes, REFRESH FAST will be available starting the next time the materialized view is refreshed.
```
http://ORA-12004.ora-code.com/

ORA-12052: is unable to fast refresh materialized view string.string

Hello

I try to create the same xx and xx, after creating a newspaper, I get this error. Follow my structure:

create table PEDIDO
(
  NR_PEDIDO        NUMBER not null,
  DESCRICAO_PEDIDO VARCHAR2(10)
);

alter table PEDIDO
  add constraint PEDIDO_PK primary key (NR_PEDIDO);

create table ITEM_PEDIDO
(
  NR_PEDIDO  NUMBER not null,
  NR_PRODUTO VARCHAR2(10) not null
);
alter table ITEM_PEDIDO
  add constraint ITEM_PK primary key (NR_PEDIDO, NR_PRODUTO);
alter table ITEM_PEDIDO
  add constraint PEDIDO_ITEM_FK foreign key (NR_PEDIDO)
  references PEDIDO (NR_PEDIDO) on delete cascade;

create index INDEX_ITEM_PEDIDO on ITEM_PEDIDO (NR_PEDIDO);

insert into pedido
values (1, 'A');

insert into pedido
values (2, 'B');

insert into item_pedido
values (1, 'X');

insert into item_pedido
values (1, 'Z');

insert into item_pedido
values (2, 'X');

commit;

When you try to create, I get the error ORA-12052:

drop materialized view log on pedido;
drop materialized view log on item_pedido;

create materialized view log on pedido;
create materialized view log on item_pedido;

create materialized view mv_pedido_item
refresh fast as
select pe.nr_pedido, pe.descricao_pedido, ip.nr_produto
  from pedido pe, item_pedido ip where pe.nr_pedido = ip.nr_pedido;

Oracle Database 10g Enterprise Edition Release 10.2.0.4.0

Hello Luiz,

Thank you for provding test cases.

SQL> drop materialized view log on pedido;
Materialized View log dropped.
SQL> drop materialized view log on item_pedido;
Materialized View log dropped.
SQL> create materialized view log on pedido
  with rowid;
Materialized View log created.
SQL> create materialized view log on item_pedido
  with rowid;
Materialized View log created.
SQL> create materialized view mv_pedido_item
refresh fast as
select pe.nr_pedido, pe.descricao_pedido, ip.nr_produto, pe.rowid pe_rowid, ip.rowid ip_rowid
  from pedido pe, item_pedido ip where pe.nr_pedido = ip.nr_pedido;
Materialized view created.

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
1 row selected.

Concerning
Peter

How to fast refresh materialized view parallel

We have Oracle 11.2.0.1 on Redhat 5.2. We use a dozen views fast refresh materialized in our application.
Occasionally refresh MV takes longer than the refresh interval.

One of the ways to improve the performance of refresh MV is to update at the same time, for example

http://www.dba-oracle.com/t_materialized_views_refreshing_performance.htm

- Use parallel DML - Oracle author Michael Armstrong Smith notes "I've done parallel materialized view refreshing
 on tables recently and improved the load times considerably. Rather than having one load which took 2 hours,
 I run 4 parallel loads, one for each partition. The length of time for the whole process is now determined by
 how long the biggest partition takes to load. In my case, this is 40 minutes, with two 30 minute loads and one
 20 minute load.  Overall I am saving 1 hour 20 minutes. I can now add further partitions and do the same thing.
 My only limitation is the parallel loads because I don't have unlimited processing power.
{code} My master tables are not partitioned, but think parallel will still better than non-parallel.

Now the question, how to make refresh parallel. According to the paragraph cited above, Use parallel DML appears doing the job. Can someone  confirm that.

We use {code}
alter materialied view MV_OFFENSE parallel REFRESH FAST start with sysdate next sysdate+ 1/24;
{code}to schedule refresh. Does the parallel clause here parallels query the MV or refresh the MV?

Any other way to make MV refresh parallel?

Thanks

Hello

Just search for * 577870.1*. But before you search, select ID of item in the source list.

Hope this helps.
Best regards
Jean Valentine

Fast refresh materialized view problems
I have two databases (A and B).

In A database, user NICK has a table called COLOUR_MASTER.
Also in this database, NICK issues creating materialized command newspaper view colour_master with the primary key, including the new values (and Yes, there is a primary key defined for this table)
In database B, there is a link of database called A_LINK, connect, Nick, identified by password using 'dbA ';
In database B, user IAN also creates a materialized view CM_MV cool off quickly in select * from colour_master@A_LINK

This statement is done correctly, and there are several million lines in CM_MV when it's done.

Immediately, IAN issued this command:

Start
dbms_mview. Refresh ('CM_MV');
end;

.. .and after a small pause, it gets the error

ORA-12008: error path refresh materialized view
ORA-02068: following sever error of A_LINK
ORA-03113: end of file on communication channel

One more + "select count (*) of colour_master@A_LINK" + subject immediately manages to return the correct number of records in the database so A 3113 is a bit misleading, I think that, in this case have crash, the database remains accessible at all times, there is no network problem (database A and B are both located in the same server so it of not like I'm trying of) connect to halfway around the globe).

The only thing I can think is that there is a permissions issue causes this error. The creation of MV because is made via a link, it is not a problem of IAN see all appropriate, but once the updates come into play, it is perhaps.

Any who can shed light on why I can't do the fast refresh from the view, I can create joyfully, please?
I'm surprised no one asked you to do what is obvious: try to do a select * from colour_master@A_LINK, without that being wrapped in a create materialized MATERIALIZED view. Just do a simple select * from...

My bet is that you will get an error ORA_22992 can not use selected from the remote tables LOB Locators . And if you can't do a simple select * in a remote table, I suspect that you can reasonably expect Fireworks when you try to create or refresh a view materialized on such a thing!

Here's a quick test:

In the 1 database:
=========
```
SQL> create table A (col1 varchar2(2), col2 clob);
Table created.

SQL> alter table A add constraint A1 primary key (col1);
Table altered.

SQL> insert into A values ('AA','This is an entry into a clob column');
1 row created.

SQL> commit;
Commit complete.

SQL> create materialized view log on A with primary key including new values;
Materialized view log created.
```
In the database 2
=========
```
SQL> connect ims_global/v0yager1@ussd
Connected.

SQL> create materialized view B refresh fast as
  2  select * from A@remotedb_link;

Materialized view created.

SQL> exec dbms_mview.refresh('B');
BEGIN dbms_mview.refresh('B'); END;

*
ERROR at line 1:
ORA-12008: error in materialized view refresh path
ORA-02068: following severe error from REMOTEDB_LINK
ORA-03113: end-of-file on communication channel
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 2251
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 2457
ORA-06512: at "SYS.DBMS_SNAPSHOT", line 2426
ORA-06512: at line 1

SQL> drop materialized view B;
Materialized view dropped.

SQL> create materialized view B refresh fast as
  2  select col1 from A@ims_link;

Materialized view created.

SQL> exec dbms_mview.refresh('B');
PL/SQL procedure successfully completed.
```
Which seems to reproduce your problem rather well, I think.

I don't know if there is no work around for this. I mean, obviously you can't miss the CLOB column in your statement of 'create a MV' as I just did, but I don't know if you're still allowed or expected to be able to create a MV on lob columns and that such and such correction will allow you to do. Maybe someone else can provide this information.

But at least you won't have to play Russian roulette with your init.ora parameters!

Fast refresh view Matt

Hi all
http://docs.Oracle.com/CD/B19306_01/server.102/b14223/basicmv.htm#i1006519

Fast refresh for a materialized view containing joins and aggregates is possible after any type of DML for the base tables (direct load or conventional INSERT , UPDATE , or DELETE ). It can be set to refresh ON COMMIT or ON DEMAND . A REFRESH ON COMMIT materialized view will be updated automatically when a transaction that is DML to one of the details of the materialized view commits tables. The time required to perform the validation may be slightly longer than usual when this method is selected. This is because the refresh operation is performed as part of the validation process. Therefore, this method may not be suitable if many users at the same time change the tables on which is based the materialized view.

1. I got this quote from the above link.
What is the refresh option by default when I use REFRESH QUICKLY? My example:

CREATE MATERIALIZED VIEW REFRESH QUICKLY ENABLE QUERY REWRITE AS mat_vw_test

SELECT *.

OF vw_test;

2 using the example 8-1 1 example: creating a materialized from the link view.

Product_sales_mv CREATE MATERIALIZED VIEW

REFRESH QUICKLY

ACTIVATE THE QUERY REWRITING

Did YOU SELECT p.prod_name, SUM (s.amount_sold) AS dollar_sales,

Count (*) AS cnt, COUNT (s.amount_sold) AS cnt_amt

S SALES, products p

WHERE s.prod_id = p.prod_id GROUP BY p.prod_name;

View of the mat will not be updated after a user execute INSERT, UPDATE, or UPDATE. fix?
How can I update the matte view after a DML statement is executed?
With the help of Oracle 11 g Release 11.2.0.4.0
Thanks in advance.

It was missing an index for a column in one of my big table.

Thanks for your help.

Best,

Materialized view fast refresh option

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