We are using the below query to create a Materialized View but it has been running since 3 hours. It is an Oracle 9i database running in HP-UX.The quey is as follows,
(SELECT
/*+ use_nl(A) parallel (A,4)*/
A.ICD_CODE AS ICD_CODE,
A.ICD_DESC AS ICD_DESC,
A.PROC_GROUP as PROC_GROUP,
B.COMPL_ICD_CODE AS COMPL_ICD_CODE,
B.COMPL_GRP_TXT AS COMPL_GRP_TXT,
C.PROC_TYPE AS PROC_TYPE ,
[code]....
In search queries generally we select 10-25 columns (more can't be displayed on the screen) from 5-10 tables
Say in case of insurance related application, the search might be on policy number, policy holder's first name, policy holder's last name, region, policy type etc.
And not to many columns we are displaying on the screen, say, 4 tables have collectively 4 * 20 = 80 columns, then we are displaying say 12-15 columns with 2-3 columns have aggregates on it.
since the search criteria (e.g. first name, last name, policy number etc.) is not known till last moment it will be a generic dynamic query
Is it possible that instead we create a Materialized view with query with only joining conditions but no filter conditions and selecting only columns to be displayed on the screen and then we will refresh the materialized view (to take care of recent business transactions) and fire refined query with filter criteria on this materialized view
Select col1,col2,col3,col4,col5
From tab1,tab2,tab3,tab4
Where tab1.col1=tab2.col1
And tab2.col2=tab3.col2
And tab2.col2=tab4.col2;
Will it improve performance of the search functionality
I have to convert some existing materialized views (fast refresh) to partition materialized views.
Database version is oracle 10.1.0.4. I have decided to use on prebuilt table option to do the partitioning as it minimizes the time to transfer from the master site.
1) stop replication
1) create interim tables with similar structure as the materialized views
2) transfer all data from the materialized views to the interim tables
4) script out the materialized views structure and add in on prebuilt table option in the scripts
5) drop the materialized views
6) rename the interim tables with the same name as the materialized views
7) run the scripts to create the materialized views with on prebuilt table option
8) refresh the newly created materialized views -> it should take a short time since I am using on prebuilt table option
But I am facing one major issue. That is if I drop the materialized views, the materialized view logs of the master tables are purged. When the materialized views are refreshed fast, there are some data missing. the data that are purged out when the materialized view are dropped.
Do you happen to know other ways that existing materialized views can be converted to partitioned materialized views? Do you have any workaround to prevent the materialized view logs from being purged?
I am stuck with a query which is taking a lot of time to execute. Below is the pseudo code of the same:
SELECT TAB_ALIAS1.COL1,TAB_ALIAS1.COL2,TAB_ALIAS1.COL3
FROM TABLE1 TAB_ALIAS1
WHERE TAB_ALIAS1.COL4 = <INPUT PARAMETER1>
AND TRUNC(TAB_ALIAS1.ELAP_TIME) =
(
SELECT MAX(ELAP_TIME)
[code]....
how joins work with in-line views.I have a query and its explain plan as below:
SELECT e.ename,e.deptno,d.dname FROM
dept d,
emp e
WHERE e.deptno=d.deptno
AND e.deptno=20
[code]....
I do not find any difference in both the explain plans. Both are same. In my second query, the filtered rows will be joined to dept table. And hence the baggage will reduce.But how can I verify that in-line view has worked better?
Name some database tool from which I can check the SQL Queries which my application is running.
NOTE: I do not want to check the queries which I am executing at the SQL command prompt but queries that are being run by my application at the backend.
SQL> select * from v$version;
BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bi
PL/SQL Release 10.2.0.4.0 - Production
CORE 10.2.0.4.0 Production
TNS for Solaris: Version 10.2.0.4.0 - Production
NLSRTL Version 10.2.0.4.0 - Production
5 rows selected.
I have a problem with views and nested selects which I cannot explain. Here is a trimed down version of the research I have done. notice the following:
1) all code is executed from the same user CDRNORMALCODE. this user has all views and procedural code
2) all data is owned by a different user CDRDATA. This user has no views and no code.
My problem is this:
If I reference the table directly with a delete statement that uses a nested select (i.e. IN clause with select), the index I expect and want is used.But if I execute the same delete but reference even the most simple of views (select * from <table>) instead of the table itself, then a full table scan is done of the table.
Here is an execute against the table directly (owned by cdrdata). Notice the reference to the table in the table schema on line 3. Also please notice INDEX RANGE SCAN BSNSS_CLSS_CASE_RULE_FK1 at the bottom of the plan.
SQL> show user
USER is "CDRNORMALCODE"
SQL>
SQL> explain plan for
2 delete
[code]...
OK, here is an update. The views I am useing normally have instead of triggers on them. If I remove the instead of trigger the problem looks like it goes away, when I put the trigger back the problem comes back.But why would an instead-of-trigger change the query plan for a view?
SQL> DELETE FROM PLAN_TABLE;
5 rows deleted.
SQL> explain plan for
2 delete
3 from BSNSS_CLSS_MNR_CASE_RULE_SV
[code]...
here we have an scenario where we want to find out all the sql statements that are executed in a particular time. The sql statements are executed via our application. I tried in awr report but it shows only the sql query which has taken long time to execute. and i even tried in V$session and V$sqlarea. how to view the executed sql statements in a particular session/current session
View 3 Replies View RelatedDoes parallel hint works in cursor queries? The cursor query is something like :
cursor c is
select /*+ parallel(s,8) */
from table ref_tab s ---- >>
<where condition>;
The table ref_tab hold data for a single day at any point of time and gets truncate before loading the next days data.On average the table holds around 7 million rows and doesn't contains any index (think that's fine as all together we are loading the whole set).And, we are using bulk logic with save exceptions to open the cursor and load the data into the target table.
I have few queries on PGA memory management.Since these queries are based on 2-3 examples not exactly same by nature I am summarising it after my understanding for the same
As I understand many workareas can be allocated to a single sql statement and number and sizes of theses workareas is controlled internally by Oracle when Automatic Memory management (PGA_aggregate_target and workarea_size_policy=Auto are set) Since many sessions share the PGA memory, the amount of memory available to each session may vary and if less amount of memory is available for a session for sorting then TEMP tablespace is used
[1] Can we say paging happens and can be checked at this time?
[2] Is there a difference in handling memory while populating pl/sql tables?
As I have encountered ora-04030 while some our developers were populating pl/sql tables but never encountered this error for sorting, hash joins etc Though I don't remember the width of pl/sql table, I am sure the developer used 'LIMIT' clause during bulk collect and still faced the issue.
With a single session on the server, I noticed that the difference in values displayed issuing 'free' command in linux and output values from sesstat did not match at all while there wasn't any heavy OS process involved during the period. I was expecting 'used' and 'free' values displayed by free command (linux) will change and difference would be approximately equals 'before and after values of session pga memory.
[3] Isn't it expected to match?
[4] Can we say in dedicated server, at any moment of time, the SUM of 'session pga memory' represents all the memory used by Oracle SGA, at that point of time?
select sum(value)/1024/1024 "memory in MB" from v$sesstat where statistic#=20;
During one of the tests I got following output (divide value by 10 for my visibility and avoid formatting)
SQL> select a.name, to_char(b.value/10, '999,999,999') value
from v$statname a, v$mystat b
where a.statistic# = b.statistic#
and a.name like '%ga memory%'; 2 3 4
[code]...
The above query is showing above values even when the pl/sql block execution is completed 30 minutes back
[5] Do we call this as 'memory leak' where memory is not released even while some time has passed since session has done something?Of course I am not checking at OS level as mentioned in question [3] above the values won't match!
Still the output of free command for reference(After the pl/sql block executed)
SQL> !free
total used free shared buffers cached
Mem: 3016796 2999660 17136 0 4308 1173260
-/+ buffers/cache: 1822092 1194704
Swap: 1048568 636124 412444
--(After the pl/sql block executed)
SQL> select * from v$pgastat;
NAMEVALUEUNIT
aggregate PGA target parameter 524288000bytes
aggregate PGA auto target 456256512bytes
global memory bound 26214400bytes
total PGA inuse 17328128bytes
[code]...
[6] What could be the significance of negative values of 'session pga memory/max'?
Last We have an OLTP system and in the night we run batch processes in 2-4 sessions
Suppose I have 10 GB RAM and with PGA setting of 3.5 GB Now I want the batch process sessions to use max possible memory during nighttime and toggle the setting back in the morning
[7] With above settings (10 GB RAM and 3.5 GB PGA) how can I divide the memory among 4 sessions?
Shall I set 1) PGA_aggregate_target=0 2)Workarea_size_policy=manual 3) Sort_are_size 4) Hash_area_size
[8] What would be approx values for parameter 3 and 4? will it be straight 3.5 GB/ 4?
We have a big hierarchical query which is now running for a long time (around 6 hours. earlier it was running for 3 hours). We have to tune this query so that we run the jobs within a stipulated time frame.
The query below inserts around 42 million records in to the table WK_ACCT_WSTORE. I have attached in the text file.
I have a created a materialized view which is based on a view on remote database. Now how do I refresh the view.
Materialized view is created by
CREATE MATERIALIZED VIEW mv_employee_name
AS SELECT EMPLID, EMPL_NAME
FROM VEMPDATA@REMOTEDB
WHERE REGION = 'US';
I am wondering how the refersh happens or how do I specify the refresh clause.REFRESH FAST option is looking for VIEW LOG on the master table but in this case its a remote view, so I cannot create any object on remote db.
I am removing sal column from table tab_emp; i want to check whether any materialized view or view using this column by querying using data dictionary :- if i use like condition against query column of all_mviews it is throwing error sicne it is long data type. is there a way to search it without creating any function and use it in a query.
View 3 Replies View RelatedI have created a materialized view and also a normal View, which has 3 tables used in both the views, when inserted new records it reflects in a normal view but when i select the materialized view i cant see the updated data.
here is the materialized view i created;
CREATE MATERIALIZED VIEW pct_sales_materialized
BUILD IMMEDIATE REFRESH ON DEMAND
ENABLE QUERY REWRITE
AS
SELECT A.DEP_NAME,B.EMP_ID,C.EMP_NAME
FROM department_head A,department_child B,emp_detail C
WHERE A.DEP_ID = B.DEP_ID
AND B.EMP_ID = C.EMP_ID
I have an issue in materialized view which has got one of the null able column and query on this column taking approximately 2 mins where as other indexed columns takes less than 10 sec.
Here is the summary
SQL> Select Count (1), Count (VAT_NO) From Mv_customer;
COUNT(1) COUNT(VAT_NO)
---------------------------------
2893561 1516
If an index is created on VAT_NO will that improve the performance. What kind of index can be created considering very less number of records has got VAT_NO
I need to create a Materialized View, which should refresh every Tuesday and Friday at 5am.
CREATE MATERIALIZED VIEW DUAL_MV
TABLESPACE USERS_SMALL
REFRESH NEXT NEXT_DAY(TRUNC(SYSDATE), 'TUESDAY') + 05/24
AS SELECT * FROM DUAL;
I can do it for single day like above, but how to refresh on multiple days, using create materialized view syntax .
I have a base table with ~20 mio. records with two FAST REFRESH Materialized Views based on that table using various aggregate functions in their view definition.
The problem is, when e.g. one record changes in the base table, I see two records in the MV log table MLOG$, but invoking the fast refresh mechanism by using using:
dbms_snapshot.refresh('mv1', 'f');
dbms_snapshot.refresh('mv2', 'f');
Is still running after ~20 minutes now.
is there some open source or free tool which can graphical display V$ Views. Can TOAD do that in a good maner?
in UNIX there is the "sar" command, but a Java tool "ksar" for displaying the statistics in user friendly fashion.
Why do we need materialized views when the normal views also serve the same purpose?
View 2 Replies View RelatedI have a problem Mat view refresh...I have to take a snapshot of the table before nsert or update to the table....below is the code written to achieve this..
create materialized view my_view refresh complete as select * from t2;
create or replace trigger TRG_T2
before insert or update on T2
declare
X number;
[code]....
However this is not getting refreshed... Also i noticed that it works for the very first time (after first insert or update) and then for successive ones it doesnt.. ..
I have a created a materialized view which is based on a view on remote database. Now how do I refresh the view.
Materialized view is created by
CREATE MATERIALIZED VIEW mv_employee_name
AS SELECT EMPLID, EMPL_NAME
FROM VEMPDATA@REMOTEDB
WHERE REGION = 'US';
how the refersh happens or how do I specify the refresh clause.
REFRESH FAST option is looking for VIEW LOG on the master table but in this case its a remote view, so I cannot create any object on remote db.
I have n number of materialized views in my schema ..I want to refresh all M_views at once by using cursor
View 3 Replies View Relatedfor following two questions.
1. I have created a materialized view with following syntax in 11g R1 database.
CREATE MATERIALIZED VIEW fr_emp_bonus_record_vw
BUILD IMMEDIATE
REFRESH COMPLETE
START WITH SYSDATE NEXT SYSDATE+1/48
ENABLE QUERY REWRITE AS
SELECT person_id, <columns>
This MV will have around 300K records and this MV will be used in other queries based on person_id. So I have created an index on mv.person_id with following syntax. I have chosen REFRESH COMPLETE, I am assuming that, Oracle truncates this table and recreates it. When it recreates this MV, does it analyze automatically or do I need to do it manually.
CREATE UNIQUE INDEX mv_u1 ON mv(person_id);
2. It takes around 2 minutes to populate 300K. While it is populating the data, if somebody accessing this view or query where this view is being used, are they going to get any error?
Can we add partitions for materialized views like tables ? ALTER TABLE owner.tablename ADD PARTITION p1 VALUES LESS THAN (2012,12);
Like is there any syntax for mview ALTER TABLE mv.mviewname ADD PARTITION ..... ?
I have 5 MViews that I want to refresh in two occasions, every Sundays and at the 1st of the month. I created a Refresh Group for the weekly and that work fine. But when I tried to created the second Refresh Group for the monthly I get a "materialized view is already in a refresh group".
You can only have a materialized view in one refresh group? What options to I have to refresh it in different intervals?
I am an Oracle newbie.
We have 2 fact tables and one lookup table in this structure:
FACTTABLE1 (C1_ID, C2, SALE)
FACTTABLE2 (C1_ID, C3, SALE)
LOOKUPTABLE (C1_ID, C1_NAME)
The DBAs have built 2 Materialized Views, which aggregates data in the fact tables at column C1 level
MAT_VIEW1 :SELECT C1_ID, SUM(SALE) SALES from FACTTABLE1 join LOOKUPTABLE on C1_ID
MAT_VIEW2: SELECT C1_ID, SUM(SALE) SALE from FACTTABLE2 join LOOKUPTABLE on C1_ID
We are using an old BI tool that can ONLY generate Inline Views in these formats.
CASE1:
select
INL_VIEW.C1_ID
,LOOKUPTABLE.C1_NAME
,sum(SALE) SALE
from
(select C1_ID, C2_ID, null C3_ID, SALE from FACTTABLE1)INL_VIEW
join LOOKUPTABLE
on INL_VIEW.C1_ID = LOOKUPTABLE.C1_ID
group by INL_VIEW.C1_ID, LOOKUPTABLE.C1_NAME
CASE2:
select
INL_VIEW.C1_ID
,LOOKUPTABLE.C1_NAME
,sum(SALE) SALE
from
(select C1_ID, null C2_ID, C3_ID, SALE from FACTTABLE2)INL_VIEW
join LOOKUPTABLE
on INL_VIEW.C1_ID = LOOKUPTABLE.C1_ID
group by INL_VIEW.C1_ID, LOOKUPTABLE.C1_NAME
CASE3:
select
INL_VIEW.C1_ID
,LOOKUPTABLE.C1_NAME
,sum(SALE) SALE
from
(
select C1_ID, C2_ID, null C3_ID, SALE from FACTTABLE1
union all
select C1_ID, C2_ID, null C3_ID, SALE from FACTTABLE2
)INL_VIEW
join LOOKUPTABLE
on INL_VIEW.C1_ID = LOOKUPTABLE.C1_ID
group by INL_VIEW.C1_ID, LOOKUPTABLE.C1_NAME
Oracle 11g rewrites Case 1 and Case 2 to use the correct materialized views. But for case 3, it goes to the base fact tables 1 and 2. Is there a way to make oracle use the MVs even if there is a UNION ALL in the inline view? There is a 1:M Foreign Key relationship between LOOKUPTABLE.C1_ID and the 2 fact tables.
We recently migrated a database from 9i to 10g (overdue we know!!) and discovered that dbms_mview.refresh default behavior was turned upside down - meaning that 10g didn't first truncate the MV to refresh it. We're trying to unwind a lot of legacy issues, but it also turns out that we also have 100 REFRESH GROUPs and 100 MATERIALIZED VIEWs. That means a 1 to 1 relationship between RGs vs MVs. There is one MV defined to each RG.
These are my questions:
1) Does a 1 to 1 relationship between RGs and MVs make sense to anybody? The original implementors are gone and we can't fathom the reason for this.
2) Is there any reason why I shouldn't convert these 100 groups to plain and simple 100 MVs? I don't want the delete/insert refresh behavior of dbms_refresh.refresh and I do want the truncate behavior of dbms_mview.refresh ATOMIC=FALSE for refreshing a standard MVIEW
What are the advantages of writable materialized views.
View 6 Replies View RelatedI have two problems.
1.I have the following query--
select name from user_snapshots where type = 'COMPLETE';
I can't do anything except running 'select' statement. NO PL/SQL as well.
how to wrote a query that counts the number of rows in individual materialized views selected by the above query.
2. How to store the result of a select statement into a variable using SQL (not PL/SQL)
select count(*) from tab;
now I want to store count of tables into a variable. Is it possible?
need to know about materialized views.
View 2 Replies View Related