performance of Materialized view

Hello Experts!

I have obligation that migrate tables to materialized views.

The current process of execution is truncate the table and updating of data that are placed on different the other schema or DB by monthly.

(insert data into an insert like the example below)

insert into emp (field 1, Field2,...) select field 1, field 2,... from table1, table2... joins defined.

If I convert the tables to materialized views.

Can I know what will be the impact of performance?

These limited data, I can only comment on a few things from generial:

1. with MV you don't have to worry about maintenance of the table.

2 performance will be much better for aggregated data. The cost of Re-calculation will be reduced to a lot because it goes in the MV as a precomputed data.

3 If you must bear the cost of the insert/update of MV, however, worry the manual activity as this will be done in real time.

Tags: Database

Similar Questions

Impact on performance at the addition of materialized view logs at the tables?
I write a very complex query for a client of our database system transaction and this will require the creation of a materialized viewbecause, all attempts at development to make acceptable performance failed.

I want to activate the fast refresh the MVIEW but I am confused about the consequences of the addition of the addition of materialized view logs to the base tables.

Some tables are large and involved in a large number of transactions and I wonder if the INSERT/update performance will be seriously affected by the presence of a newspaper mview.

Maybe it's a simple question, but I was unable to find an answer very clear in the literature.

Thanks for all the answers!

Chris Mills
Biotechnology data management consultant
There is an overload for the newspapers of the view materialized, a little less, but roughly on par with a trigger that writes to a table.

If it is an OLTP system where you do a lot of low-value transactions, the general expenses percentage is probably not particularly great, something in the range of 5-10% maybe (although, of course, by running tests in the development environment would be desirable). If there are loads in bulk, the impact of the percentage could be higher.

Justin

performance of the queries on the main tables of the materialized view vs
Hello

I'm afraid of strange behavior in db, on my paintings of master UDBMOVEMENT_ORIG (26mil.rows) and UDBIDENTDATA_ORIG (18mil.rows) is created the materialized view TMP_MS_UDB_MV (UDBMOVEMENT stands for this object) that meets certain default conditions and the join on these paintings of master condition. MV got on the lines of 12milions. I created MV for poll not so huge objects, MV got 3GB, paintings of master toghether 12 GB. But I don't understand that physical reads and becomes compatible is less on MV that on the main tables, the final execution time is shorter on the master tables. See my journal below.

Why?

Thanks for the replies.

SQL > set echo on
SQL > @flush
SQL > alter system flush buffer_cache;

Modified system.

Elapsed time: 00:00:00.20
SQL > alter system flush shared_pool;

Modified system.

Elapsed time: 00:00:00.65
SQL > SELECT
UDBMovement.zIdDevice 2, UDBMovement.sDevice, UDBMovement.zIdLocal, UDBMovement.sComputer, UDBMovement.tActionTime, UDBIdentData.sCardSubType, UDBIdentData.sCardType, UDBMovement.cEpan, UDBMovement.cText, UDBMovement.lArtRef, UDBMovement.sArtClassRef, UDBMovement.lSequenz, UDBMovement.sTransMark, UDBMovement.lBlock, UDBMovement.sTransType, UDBMovement.lGlobalID, UDBMovement.sFacility, UDBIdentData.sCardClass, UDBMovement.lSingleAmount, UDBMovement.sVAT, UDBMovement.lVATTot, UDBIdentData.tTarifTimeStart, UDBIdentData.tTarifTimeEnd, UDBIdentData.cLicensePlate, UDBIdentData.lMoneyValue, UDBIdentData.lPointValue, UDBIdentData.lTimeValue, UDBIdentData.tProdTime, UDBIdentData.tExpireDate
UDBMOVEMENT_orig UDBMovement 3, Udbidentdata_orig UDBIdentData
4. WHERE
5 UDBMovement.lGlobalId = UDBIdentData.lGlobalRef (+) AND UDBMovement.sComputer = UDBIdentData.sComputer (+)
6 AND UDBMovement.sTransType > 0 AND UDBMovement.sDevice < 1000 AND UDBMovement.sDevice > = 0 AND UDBIdentData.sCardType IN (2) AND (bitand(UDBMovement.sSaleFlag,1) = 0 AND bitand(UDBMovement.sSaleFlag,4) = 0) AND UDBMovement.sArtClassRef < 100
7 AND UDBMovement.tActionTime > = TO_DATE (May 5, 2011 00:00:00 ',' dd/mm/yyyy hh24:mi:ss') + 0.25 AND UDBMovement.tActionTime < TO_DATE (May 5, 2011 00:00:00 ',' dd/mm/yyyy hh24:mi:ss') + 0.5
8 ORDER BY tActionTime, lBlock, lSequenz;

4947 selected lines.

Elapsed time: 00:00:15.84

Execution plan
----------------------------------------------------------
Hash value of plan: 1768406139

------------------------------------------------------------------------------------------------------------
| ID | Operation | Name | Lines | Bytes | TempSpc | Cost (% CPU). Time |
------------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | 7166 | 1238K | 20670 (1) | 00:04:09 |
| 1. SORT ORDER BY | 7166 | 1238K | 1480K | 20670 (1) | 00:04:09 |
| 2. NESTED LOOPS |
| 3. NESTED LOOPS | 7166 | 1238K | 20388 (1) | 00:04:05 |
|* 4 | TABLE ACCESS BY INDEX ROWID | UDBMOVEMENT_ORIG | 7142 | 809K | 7056 (1) | 00:01:25 |
|* 5 | INDEX RANGE SCAN | IDX_UDBMOVARTICLE | 10709. 61 (0) | 00:00:01 |
|* 6 | INDEX UNIQUE SCAN | UDBIDENTDATA_PRIM | 1 | | | 1 (0) | 00:00:01 |
|* 7 | TABLE ACCESS BY INDEX ROWID | UDBIDENTDATA_ORIG | 1. 61. 2 (0) | 00:00:01 |
------------------------------------------------------------------------------------------------------------

Information of predicates (identified by the operation identity card):
---------------------------------------------------

4 - filter("UDBMOVEMENT".") STRANSTYPE"> 0 AND 'UDBMOVEMENT '. "" SDEVICE ' < 1000 AND
BITAND ("SSALEFLAG", 1) = 0 AND "UDBMOVEMENT". "" SDEVICE ' > = 0 AND BITAND ("UDBMOVEMENT". "SSALEFLAG «(, 4) = 0)" "
5 - access("UDBMOVEMENT".") TACTIONTIME' > = TO_DATE (' 2011-05-05 06:00 ',' syyyy-mm-jj)
('HH24:mi:SS) AND "UDBMOVEMENT". "' TACTIONTIME ', TO_DATE (' 2011-05-05 12:00 ',' syyyy-mm-jj)
('HH24:mi:SS) AND "UDBMOVEMENT". ("' SARTCLASSREF" < 100)
filter ("UDBMOVEMENT". "SARTCLASSREF" < 100)
6 - access("UDBMOVEMENT".") LGLOBALID "=" UDBIDENTDATA. " "" LGLOBALREF "AND
'UDBMOVEMENT '. "' SCOMPUTER"="UDBIDENTDATA." ("' SCOMPUTER")
7 - filter("UDBIDENTDATA".") SCARDTYPE "= 2)

Statistics
----------------------------------------------------------
543 recursive calls
0 db block Gets
84383 compatible Gets
4485 physical reads
0 redo size
533990 bytes sent via SQL * Net to client
3953 bytes received via SQL * Net from client
331 SQL * Net back and forth to and from the client
kinds of 86 (memory)
0 sorts (disk)
4947 lines processed

SQL > @flush
SQL > alter system flush buffer_cache;

Modified system.

Elapsed time: 00:00:00.12
SQL > alter system flush shared_pool;

Modified system.

Elapsed time: 00:00:00.74
SQL > SELECT UDBMovement.zIdDevice, UDBMovement.sDevice, UDBMovement.zIdLocal, UDBMovement.sComputer, UDBMovement.tActionTime, UDBMovement.sCardSubType, UDBMovement.sCardType, UDBMovement.cEpan, UDBMovement.cText, UDBMovement.lArtRef, UDBMovement.sArtClassRef, UDBMovement.lSequenz, UDBMovement.sTransMark, UDBMovement.lBlock, UDBMovement.sTransType, UDBMovement.lGlobalID, UDBMovement.sFacility, UDBMovement.sCardClass, UDBMovement.lSingleAmount, UDBMovement.sVAT, UDBMovement.lVATTot, UDBMovement.tTarifTimeStart, UDBMovement.tTarifTimeEnd, UDBMovement.cLicensePlate, UDBMovement.lMoneyValue, UDBMovement.lPointValue, UDBMovement.lTimeValue, UDBMovement.tProdTime
2. OF UDBMOVEMENT WHERE
3 UDBMovement.sTransType > 0 AND UDBMovement.sDevice < 1000 AND UDBMovement.sDevice > = 0 AND UDBMovement.sCardType IN (2) AND (bitand(UDBMovement.sSaleFlag,1) = 0 AND bitand(UDBMovement.sSaleFlag,4) = 0) AND UDBMovement.sArtClassRef < 100
4. AND UDBMovement.tActionTime > = TO_DATE (May 5, 2011 00:00:00 ',' the hh24: mi: ss' dd/mm/yyyy) + 0.25
5 AND UDBMovement.tActionTime < TO_DATE (May 5, 2011 00:00:00 ',' the hh24: mi: ss' dd/mm/yyyy) + 0.5 ORDER BY tActionTime, lBlock, lSequenz;

4947 selected lines.

Elapsed time: 00:00:26.46

Execution plan
----------------------------------------------------------
Hash value of plan: 3648898312

-----------------------------------------------------------------------------------------------------------
| ID | Operation | Name | Lines | Bytes | Cost (% CPU). Time |
-----------------------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | 2720 | 443K | 2812 (1) | 00:00:34 |
| 1. SORT ORDER BY | 2720 | 443K | 2812 (1) | 00:00:34 |
|* 2 | MAT_VIEW ACCESS BY INDEX ROWID | TMP_MS_UDB_MV | 2720 | 443K | 2811 (1) | 00:00:34 |
|* 3 | INDEX RANGE SCAN | EEETMP_MS_ACTTIMEDEVICE | 2732 | 89 (0) | 00:00:02 |
-----------------------------------------------------------------------------------------------------------

Information of predicates (identified by the operation identity card):
---------------------------------------------------

2 - filter("UDBMOVEMENT".") STRANSTYPE"> 0 AND BITAND ("UDBMOVEMENT". "SSALEFLAG «(, 4) = 0 AND" "
BITAND ("SSALEFLAG", 1) = 0 AND "UDBMOVEMENT". ("' SARTCLASSREF" < 100)
3 - access("UDBMOVEMENT".") TACTIONTIME' > = TO_DATE (' 2011-05-05 06:00 ',' syyyy-mm-jj)
('HH24:mi:SS) AND "UDBMOVEMENT". "" SDEVICE ' > = 0 AND "UDBMOVEMENT". ' SCARDTYPE ' = 2 AND ".
'UDBMOVEMENT '. "" TACTIONTIME "< TO_DATE(' 2011-05-05 12:00:00', 'syyyy-mm-dd hh24:mi:ss') AND
'UDBMOVEMENT '. ("' SDEVICE ' < 1000)
filter ("UDBMOVEMENT". "SCARDTYPE"= 2 AND "UDBMOVEMENT"." SDEVICE' < 1000 AND
'UDBMOVEMENT '. ("' SDEVICE ' > = 0)

Statistics
----------------------------------------------------------
449 recursive calls
0 db block Gets
6090 gets coherent
2837 physical reads
0 redo size
531987 bytes sent via SQL * Net to client
3953 bytes received via SQL * Net from client
331 SQL * Net back and forth to and from the client
168 sorts (memory)
0 sorts (disk)
4947 lines processed

SQL > spool off

Published by: MattSk on February 4, 2013 14:20
>
The second query makes a full table of materialized view scan.
>
What you base that statement on?

I do not see any table full scan in terms of the second query. All I see is
>
* 2 MAT_VIEW ACCESS BY INDEX ROWID TMP_MS_UDB_MV 2720 443K 2811 (1) 00:00:34

Re: view opaque and the materialized view

Hi Experts,
I want some clarification of opaque and view view in the physical layer OBIEE materialized
-> what is the main difference between the opaque view and materialized in the RPD perspective view, we have to do this at the level of the RPD or DB.
-> I want the list of opaque opinion and materialized in the RPD view how I should do.
-> How opaque views will degrade the performance and how a materialized view will improve performance at the level of the report.
-> In scenarios that we use view opaque and the view materialized (if possible with a scenario for the best permanent basis).
Thanks in advance.

I want some clarification of opaque and view view in the physical layer OBIEE materialized

-> What is the main difference between opaque view and create the materialized view in the RPD point of view, we have to do this at the level of the RPD or DB.

Opaque views is a SQL statement that is defined in the physical layer, OBIEE will use all in the construction of a SQL query. In a way it's not different from a database view, except it is set in OBIEE only. Alternatively, you can deploy an Opaque view, which pushes its definition in the database. Read more about it here: work with physical tables, Cubes and joins - 11 g Release 1 (11.1.1)

A materialized view (MV) is a database concept where the results of a SQL statement are physicalised like a table, and therefore as OBIEE is a MV is just another physical array

-> If I want a list of the opaque views and materialized in the RPD view how I should do.

To find opaque views, use the function «Repository of applications» administration tool Search physical Tables and set up a filter on the Type = Select

Screenshot: https://www.evernote.com/shard/s16/sh/5c843e47-bff1-4d4b-b847-be98f3a2ec09/cf060a6cd9805f687fa0b5b46f3f0020

To find materialized views, you will need to query the catalog in your database (for example select object_name, object_type from user_objects where type_objet = "MATERIALIZED VIEW" ;) and compare it to the list of tables in your SPR)

-> How opaque views will degrade the performance and how a materialized view will improve performance at the level of the report.

A materialized view is materialized, in other words, the results are already stored in the database. This means usually there will be more efficient because all the joins and aggregations, etc. will be settled in advance.

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.

extracting data from the CLOB using materialized views

Hello
We have xml data from clob which I have a requirement to extract (~ 50 attributes) on a daily basis, so we decided to use materialized views with refreshes full (open good suggestions)
A small snippet of code
CREATE THE MWMRPT MATERIALIZED VIEW. TASK_INBOUND
IMMEDIATE CONSTRUCTION
FULL REFRESH ON DEMAND
WITH ROWID
AS
SELECT M.TASK_ID, M.BO_STATUS_CD, b.*
OF CISADM. M1_TASK m,
XMLTABLE (' / a ' XMLPARSE PASSING ())
CONTENT '< a > | M.BO_DATA_AREA | "< /a >."
) COLUMNS
serviceDeliverySiteId varchar2 (15) PATH
"cmPCGeneralInfo/serviceDeliverySiteId"
serviceSequenceId varchar2 (3) PATH "cmPCGeneralInfo/serviceSequenceId"
completedByAssignmentId varchar2 (50) PATH "completedByAssignmentId."
Cust_id varchar2 (10) PATH "cmPCCustomerInformation/customerId,"
ACCT_SEQ varchar2 (5) PATH "customerInformation/accountId"
AGRMT_SEQ varchar2 (5) PATH cmPCCustomerAgreement/agreementId"."
COLL_SEQ varchar2 (5) PATH "cmPCGeneralInfo/accountCollectionSeq"
REVENUE_CLASS varchar2 (10) PATH "cmPCCustomerAgreement/revenueClassCode"
REQUESTED_BY varchar2 (50) PATH ' attributes customerInformation/contactName',...~50
This ddl ran > 20 hours and no materialized view created. There are certain limits that we have
- Cannot create a materialized view log
- cannot change the source as its defined provider table
- cannot do an ETL
DB is 11g R2
Any ideas/suggestions are very much appreciated

I explored a similar approach, using the following test case.

It creates a table "MASTER_TABLE" containing 20,000 lines and a CLOB containing an XML fragment like this:

09HOLVUF3T6VX5QUN8UBV9BRW3FHRB9JFO4TSV79R6J87QWVGN

UUL47WDW6C63YIIBOP1X4FEEJ2Z7NCR9BDFHGSLA5YZ5SAH8Y8

O1BU1EXLBU945HQLLFB3LUO03XPWMHBN8Y7SO8YRCQXRSWKKL4

...

1HT88050QIGOPGUHGS9RKK54YP7W6OOI6NXVM107GM47R5LUNC

9FJ1JZ615EOUIX6EKBIVOWFDYCPQZM2HBQQ8HDP3ABVJ5N1OJA

then an intermediate table "MASTER_TABLE_XML" with the same columns with the exception of the CLOB which turns into XMLType and finally a MVIEW:

SQL > create table master_table like

2. Select level as id

3, cast ('ROW' | to_char (Level) as varchar2 (30)) as the name

4       , (

5. Select xmlserialize (content

XMLAGG 6)

7 xmlelement (evalname ('ThisIsElement' | to_char (Level)), dbms_random.string ('X', 50))

8                    )

9 as clob dash

10                  )

11 double

12 connect by level<=>

(13) as xmlcontent

14 double

15 connect by level<= 20000="">

Table created.

SQL > call dbms_stats.gather_table_stats (user, 'MASTER_TABLE');

Calls made.

SQL > create table (master_table_xml)

Identification number 2

3, name varchar2 (30)

4, xmlcontent xmltype

5)

binary xmltype 6 securefile XML column xmlcontent store

7;

Table created.

SQL > create materialized view master_table_mv

2 build postponed

full 3 Refresh on demand

4, as

5. Select t.id

6, t.nom

7       , x.*

master_table_xml 8 t

9, xmltable ('/ r' in passing t.xmlcontent)

10 columns

11 path of varchar2 (50) ThisIsElement1 'ThisIsElement1 '.

12, path of varchar2 (50) ThisIsElement2 'ThisIsElement2 '.

13, path of varchar2 (50) ThisIsElement3 'ThisIsElement3 '.

14, path of varchar2 (50) ThisIsElement4 'ThisIsElement4 '.

15 road of varchar2 (50) ThisIsElement5 'ThisIsElement5 '.

16, road of varchar2 (50) ThisIsElement6 'ThisIsElement6 '.

17 road of varchar2 (50) ThisIsElement7 'ThisIsElement7 '.

18 road of varchar2 (50) ThisIsElement8 'ThisIsElement8 '.

19 road to varchar2 (50) ThisIsElement9 'ThisIsElement9 '.

20, path of varchar2 (50) ThisIsElement10 'ThisIsElement10 '.

21, road to varchar2 (50) ThisIsElement11 'ThisIsElement11 '.

22 road of varchar2 (50) ThisIsElement12 'ThisIsElement12 '.

23 road of varchar2 (50) ThisIsElement13 'ThisIsElement13 '.

24, path of varchar2 (50) ThisIsElement14 'ThisIsElement14 '.

25 road of varchar2 (50) ThisIsElement15 'ThisIsElement15 '.

26, path of varchar2 (50) ThisIsElement16 'ThisIsElement16 '.

27, way to varchar2 (50) ThisIsElement17 'ThisIsElement17 '.

28 road of varchar2 (50) ThisIsElement18 'ThisIsElement18 '.

29 road of varchar2 (50) ThisIsElement19 'ThisIsElement19 '.

30, path of varchar2 (50) ThisIsElement20 'ThisIsElement20 '.

31, path of varchar2 (50) ThisIsElement21 'ThisIsElement21 '.

32 road of varchar2 (50) ThisIsElement22 'ThisIsElement22 '.

33, path of varchar2 (50) ThisIsElement23 'ThisIsElement23 '.

34 road of varchar2 (50) ThisIsElement24 'ThisIsElement24 '.

35 road of varchar2 (50) ThisIsElement25 'ThisIsElement25 '.

36, road to varchar2 (50) ThisIsElement26 'ThisIsElement26 '.

37, path of varchar2 (50) ThisIsElement27 'ThisIsElement27 '.

38, path of varchar2 (50) ThisIsElement28 'ThisIsElement28 '.

39, path of varchar2 (50) ThisIsElement29 'ThisIsElement29 '.

40, road of varchar2 (50) ThisIsElement30 'ThisIsElement30 '.

41 road of varchar2 (50) ThisIsElement31 'ThisIsElement31 '.

42, path of varchar2 (50) ThisIsElement32 'ThisIsElement32 '.

43, road to varchar2 (50) ThisIsElement33 'ThisIsElement33 '.

44, path of varchar2 (50) ThisIsElement34 'ThisIsElement34 '.

45, path of varchar2 (50) ThisIsElement35 'ThisIsElement35 '.

46, path of varchar2 (50) ThisIsElement36 'ThisIsElement36 '.

47, path of varchar2 (50) ThisIsElement37 'ThisIsElement37 '.

48, path of varchar2 (50) ThisIsElement38 'ThisIsElement38 '.

49, path of varchar2 (50) ThisIsElement39 'ThisIsElement39 '.

50 road of varchar2 (50) ThisIsElement40 'ThisIsElement40 '.

51, path of varchar2 (50) ThisIsElement41 'ThisIsElement41 '.

52, path of varchar2 (50) ThisIsElement42 'ThisIsElement42 '.

53, path of varchar2 (50) ThisIsElement43 'ThisIsElement43 '.

54, path of varchar2 (50) ThisIsElement44 'ThisIsElement44 '.

55 road of varchar2 (50) ThisIsElement45 'ThisIsElement45 '.

56, path of varchar2 (50) ThisIsElement46 'ThisIsElement46 '.

57, path of varchar2 (50) ThisIsElement47 'ThisIsElement47 '.

58 road of varchar2 (50) ThisIsElement48 'ThisIsElement48 '.

59 road of varchar2 (50) ThisIsElement49 'ThisIsElement49 '.

60 road of varchar2 (50) ThisIsElement50 'ThisIsElement50 '.

(61) x;

Materialized view created.

The discount is then performed in two steps:
1. INSERT INTO master_table_xml
2. Refresh the MVIEW
(Note: as we insert in an XMLType column, we need an XML (only root) document this time)

SQL > set timing on

SQL >

SQL > truncate table master_table_xml;

Table truncated.

Elapsed time: 00:00:00.27

SQL >

SQL > insert into master_table_xml

2. select id

3, name

4, xmlparse (document '' |) XmlContent |'')

5 master_table;

20000 rows created.

Elapsed time: 00:04:38.72

SQL >

SQL > call dbms_mview.refresh ('MASTER_TABLE_MV');

Calls made.

Elapsed time: 00:00:22.42

SQL >

SQL > select count (*) in the master_table_mv;

COUNT (*)

----------

20000

Elapsed time: 00:00:01.38

SQL > truncate table master_table_xml;

Table truncated.

Elapsed time: 00:00:00.41

Create Materialized view and Materialized view log.

I wanted to create a materialized view with option "REFRESH QUICKLY YOU COMMIT".
(1) table 1 - it is partitioned range + list - added primary key
(2) View1 - having primary keys on the base table of view
Steps to follow:
(1) create the materialized on Table1; view journal -primary key by default
(2) create the materialized on view1 view log. -It gives below error.
ORA-00942: table or view does not exist
I wanted to create Materialized view as below
create a materialized view
Quickly REFRESH ON validation
as
Select...
........
... from table1
where c1 (select c1 from View1 which...);

Question:
(1) because I am getting above error when creating journal of MV on the view. Can one create log view MV or we create a MV newspaper on the base table of view?
(2) to create the MV with "REFRESH QUICKLY YOU COMMIT' option, we need to have the primary key on the main tables?

Pointers on this will be really useful.

Thank you
Prasad

"When a materialized view is maintained by the ON COMMIT method, the time required to perform the validation can be slightly longer than usual." This is because the refresh operation is performed as part of the validation process. This is why this method may not be suitable if many users at the same time change the tables on which is based the materialized view. »

See: basis of materialized views (refreshment options) for all the other options and how they work.

Elapsed time for the materialized view vs Master table query
Hello all;

Small confusion about time up for the vs Master materialized view table query

SQL > select count (*), sum (quan_sold), sum (amt_sold) of the sale;
COUNT (*) SUM (QUAN_SOLD) SUM (AMT_SOLD)
6000000 12000000 720480000
Elapsed time: 00:00:30.54

SQL > create materialized view mv1
2 activate the rewrite of the query as
3. select count (*), sum (quan_sold), sum (amt_sold) of the sale;
Materialized view created.
Elapsed time: 00:00:01.45

SQL > select count (*), sum (quan_sold), sum (amt_sold) of the sale;
COUNT (*) SUM (QUAN_SOLD) SUM (AMT_SOLD)
6000000 12000000 720480000
Elapsed time: 00:00:00.01

Please see the three cases "Elapsed Time"...

When comparing other cases.
1. my query takes long time (30.54), extraction of data from the sale
2. create a materialized view takes less time (01:45) why?

Source: http://uhesse.com/2009/07/08/brief-introduction-into-materialized-views/
>
Small confusion about elapsed time for the materialized view vs Master table query

SQL > select count (*), sum (quan_sold), sum (amt_sold) from the sale.

COUNT (*) SUM (QUAN_SOLD) SUM (AMT_SOLD)
6000000 12000000 720480000
Elapsed time: 00:00:30.54

SQL > create materialized view mv1
2 activate the rewrite of the query as
3. select count (*), sum (quan_sold), sum (amt_sold) of the sale;
Materialized view created.
Elapsed time: 00:00:01.45

SQL > select count (*), sum (quan_sold), sum (amt_sold) from the sale.

COUNT (*) SUM (QUAN_SOLD) SUM (AMT_SOLD)
6000000 12000000 720480000
Elapsed time: 00:00:00.01

Please see the three cases "Elapsed Time"...

When comparing other cases.
1. my query takes long time (30.54), extraction of data from the sale
2. create a materialized view takes less time (01:45) why?
>
Many queries take less time the second time you run them. After the first performance, there may be many, if not all, lines in the buffer cache. Then the second round will not make any or all e/s physical but will obtain data from the buffer cache.

Also, you haven't checked that the MV was even used for the second run.

Drop the MV and make the query several times and means of the time. Then create the MV and do the same thing.

Implementation of materialized view (10.2.0.5) - more than an hour to create
A distributed query (remote several tables, several spaces), all refresh on demand. Note that I have no control over remote tables (impossible to create logs of MV, etc.) and I ask really just the difference in performance between the direct request and the MV.

My MV script:

CREATE MYSCHEMA MATERIALIZED VIEW. PRE-MEDICATION
STORAGE)
DEFAULT USER_TABLES
DEFAULT FLASH_CACHE
DEFAULT CELL_FLASH_CACHE
)
NOCACHE
NOLOGGING
NOCOMPRESS
NOPARALLEL
IMMEDIATE CONSTRUCTION
FULL REFRESH ON DEMAND
AS
< my query >

The query takes less than 2 seconds to turn, return of 600 lines. When you try to create the MV, I gave up after an hour. There is no index on the MV (of course, as I have not yet even created). The only hint in the query is to specify the table driven as the remote source.

I did not request (I'll do it if necessary) because I'm not as interested tuning the query as I am to determine why the MV would be so ridiculously slow compared to the query itself.
>
The disappointing aspect of all this is that the query is essentially made of 3 tables remote (all from the same source, probably less than 1 k lines when joined to the top) and 1 local table (table of correspondence of line 37) while straight equi-joins.
>
Your solution is obvious.

Create a local MV based ONLY on these 3 remote tables.

Then create your required local MV based on this new local MV first and your local table.

If these 3 remote lookup tables are even of the very useful by themselves and then create THREE local MVs, one for each of the remote tables.

And build your local MV required on the three new local VM and your local table.

You can add the MVs local to a group of refresh to refresh all at once with two approaches

An approach fracture rule often works well especially with as small as your tables.

create materialized view log on the table without a primary key

Hi all

CREATE TABLE client_months 
(
  SUBJ_CODE         NUMBER(4),
  SERV_CODE         NUMBER(4),
  DEBIT_CODE        NUMBER(4),
  PERIOD_NUM        NUMBER(2),
  PERIOD_NAME       VARCHAR2(40 CHAR),
  FIRST_MON_DAY     DATE,
  LAST_MON_DAY      DATE,
  VALUE_MON_DAY     DATE,
  MONTHES           NUMBER(4,2),
  GARDENING_WEIGHT  NUMBER(5,4),
  REASON_CODE       NUMBER(5),
  STAMP_ACTION      VARCHAR2(1 CHAR),
  STAMP_CDATE       DATE                        DEFAULT SYSDATE,
  STAMP_DATE        DATE,
  STAMP_USER        VARCHAR2(15 CHAR),
  REGION_CODE       NUMBER(9)
)
table created.

CREATE UNIQUE INDEX client_months_UK  ON client_months 
(SUBJ_CODE, SERV_CODE, DEBIT_CODE, PERIOD_NUM, REGION_CODE)
index created.

CREATE MATERIALIZED VIEW LOG ON client_months with rowid;

CREATE MATERIALIZED VIEW client_months_mv 
BUILD immediate 
REFRESH FAST ON COMMIT 
AS 
SELECT * FROM client_months;

ORA-12014: table 'CLIENT_MONTHS' does not contain a primary key constraint

I don't want to refresh the mview when validation is performed on the base table.
And I don't want to change the base table by adding a primary key.

is it possible to create the mview journal using the unique index? or another solution?
Please help
Thanks in advance
Naama

Naamas wrote:
No,
I already read this post!

Then you read wrong:

SQL> CREATE TABLE client_months
  2  (
  3    SUBJ_CODE         NUMBER(4),
  4    SERV_CODE         NUMBER(4),
  5    DEBIT_CODE        NUMBER(4),
  6    PERIOD_NUM        NUMBER(2),
  7    PERIOD_NAME       VARCHAR2(40 CHAR),
  8    FIRST_MON_DAY     DATE,
  9    LAST_MON_DAY      DATE,
 10    VALUE_MON_DAY     DATE,
 11    MONTHES           NUMBER(4,2),
 12    GARDENING_WEIGHT  NUMBER(5,4),
 13    REASON_CODE       NUMBER(5),
 14    STAMP_ACTION      VARCHAR2(1 CHAR),
 15    STAMP_CDATE       DATE                        DEFAULT SYSDATE,
 16    STAMP_DATE        DATE,
 17    STAMP_USER        VARCHAR2(15 CHAR),
 18    REGION_CODE       NUMBER(9)
 19  )
 20  /

Table created.

SQL> CREATE UNIQUE INDEX client_months_UK  ON client_months
  2  (SUBJ_CODE, SERV_CODE, DEBIT_CODE, PERIOD_NUM, REGION_CODE)
  3  /

Index created.

SQL> CREATE MATERIALIZED VIEW LOG ON client_months with rowid
  2  /

Materialized view log created.

SQL> CREATE MATERIALIZED VIEW client_months_mv
  2  BUILD immediate
  3  REFRESH FAST WITH ROWID ON COMMIT -- pay attention to WITH ROWID
  4  AS
  5  SELECT * FROM client_months
  6  /

Materialized view created.

SQL>

SY.

Refreshin materialized view
We have created the MV in the database, how can I automatically refresh with any tool-
Soloman simply uses a shortcut:

1 day = 24 hours

So he decided he wants to start tomorrow at 8. am

That's so trunc (sysdate) = midnight + 1 day + 8 hrs

but 1 day = 24/24
and 8 = 8/24

So what did = 32/24

What factors down (divide by 8)
4/3

P.S. According your materialized view, you can also use the update on the validate option. Soloman gave you an option to perform a full refresh of the data.

Published by: Keith Jamieson December 21, 2012 17:03

Materialized view conducive to fast refresh method
In AWM when I select refresh FASTER method and select the materialized view, get the error below:
"Quick Refresh method requires the materialized view logs and a complete refresh previously run the MV cube." I need this fast a cube materialized view refresh, so that it performs an incremental refresh and re-aggregation of only the changed lines in the source table.
can someone help me on this?
Remember to choose the 'Force' that runs fast if possible update, as otherwise it performs a complete refresh. You can also specify Complete as the Refresh method in the dialog box Assistant Maintenance first, you keep the cube.

You'll need create materialized on all the base tables, view logs if you have not already done so, otherwise the cube will be able to do a fast refresh (differential).

Cannot create Materialized View using the PL/SQL procedure

Hello

I have a question related to the creation of materialized view.
I have a stored procedure that creates the materialized view. When you try to perform this procedure, I get not enough privileges error: ORA-01031.

When I run the content of this procedure as a PL/SQL block anonymous their materialized view is created without any complications.
Can you please advice me on this subject?
It is even possible to create a materialized view in the stored procedure as I found no info on this subject.

Thank you
Petr

Hi chudapet,

Whenever you make in procedure, you must have direct subsidies and not through a role.

Most likely the grant to create a materialized view is available via a role to your username.
Assign a direct grant to the user:

grant create materialized view to scott;
{code}

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

Materialized view Site DB Migration
Hi guys,.

Need advice on the below:

We currently have this configuration in our environment:
Master DB1 site (HP - UX Itanium)
Site of DB2 Mview (HP - UX Itanium)

We use the replication at the table level.
Basically a NEWSPAPER MVIEW will be created for each table in the DB1 and fast table refresh is scheduled in DB2 MVIEW SITE daily between 02:00 and 05:00.

We have a requirement to migrate the site mview DB2 for HP - UX to Solaris. (version of db remains)
The size of the database is about 500 GB.

1. can I use the cold backup in HP - UX Itanium, and restoration to the Solaris? Is it supported?
2. our database is 500 GB which is pretty huge. So cold backup and restore method cannot be used, is recommended for a such enormous data base exp and imp? It will take quite long I think.
3. everyday mview fast replication is scheduled between 02:00 and 05:00. If we were to use the exp and imp for the
migration of the mView, the mview site will still work after importing? Complications? For example, after importing, the mview still will know where to continue to replicate based on the log of snapshot in the master probably due to the id of the row changed in mview site?
4. any recommendation to perform the above task? DB version is 10.2.0.5

Thank you!
Hello

My case is abit different as it is a site of mview.

Transportable tablespace will transport mviews as well?

This MOS score could be interesting in this case:

* How to manage materialized views when you upgrade or clone a database [ID 1406586.1] *.

But beware, this procedure has not been tested for all the version of Oracle.

You must test it before on an environment of 'test '.

Hope this helps.
Best regards
Jean Valentine

performance of Materialized view

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