What is the difference between view and materialised view?
Answers were Sorted based on User's Feedback
Answer / sindhu
View - store the SQL statement in the database and let you
use it as a table. Every time you access the view, the SQL
statement executes.
Materialized view - stores the results of the SQL in table
form in the database. SQL statement only executes once and
after that every time you run the query, the stored result
set is used. Pros include quick query results
| Is This Answer Correct ? | 14 Yes | 0 No |
Answer / anju
materialized view can be used to precalculate the expensive
joins and aggregates prior to execution and the result is
stored in a table in database and can refer to it in
future. the adv of this is increse in performance.
view is nothing but an sql query stored. it will not store
data in tables
| Is This Answer Correct ? | 5 Yes | 0 No |
Answer / atiric sofrware(raja)
Views contains query whenever execute views it has read from
base table
Where as Materialised views loading or replicated takes
place only once which gives you better query performance
Refresh materialised views
1.on commit
2. on demand
(Complete, never, fast, force)
| Is This Answer Correct ? | 2 Yes | 0 No |
Answer / praveen kumar pendekanti
In view if we do any operation that may be changes in table
and viveversa.View dont have memery allocation.if we create
a view as 'v1' on emp table and then we delete the emp
table there by 'v1' name will be exist in view list, but
data will not be there, if we create the emp table once
again it will automatically link to that 'v1'view.
But in the case of M.views the changes that made in table
cannot be seen in M.view.M.views have separate memery
allocation if we delete the table the M.view will be there.
M.view is read only view,D.D.L oerations are not possible
on this M.view. M.view are used in dataware housing.
| Is This Answer Correct ? | 1 Yes | 0 No |
There are 2 files, Master and User. We need to compare 2 files and prepare a output log file which lists out missing Rolename for each UserName between Master and User file. Please find the sample data- MASTER.csv ---------- Org|Tmp_UsrID|ShortMark|Rolename ---|---------|----------|------------ AUS|0_ABC_PW |ABC PW |ABC Admin PW AUS|0_ABC_PW |ABC PW |MT Deny all GBR|0_EDT_SEC|CR Edit |Editor GBR|0_EDT_SEC|CR Edit |SEC MT103 GBR|0_EDT_SEC|CR Edit |AB User USER.csv -------- Org|UserName|ShortMark|Rolename ---|--------|---------|------------ AUS|charls |ABC PW |ABC Admin PW AUS|amudha |ABC PW |MT Deny all GBR|sandya |CR Edit |Editor GBR|sandya |CR Edit |SEC MT103 GBR|sandya |CR Edit |AB User GBR|sarkar |CR Edit |Editor GBR|sarkar |CR Edit |SEC MT103 Required Output file: --------------------- Org|Tmp_UsrID|UserName|Rolename |Code ---|---------|--------|------------|-------- AUS|0_ABC_PW |charls |ABC Admin PW|MATCH AUS|0_ABC_PW |charls |MT Deny all |MISSING AUS|0_ABC_PW |amudha |ABC Admin PW|MISSING AUS|0_ABC_PW |amudha |MT Deny all |MATCH GBR|0_EDT_SEC|sandya |Editor |MATCH GBR|0_EDT_SEC|sandya |SEC MT103 |MATCH GBR|0_EDT_SEC|sandya |AB User |MATCH GBR|0_EDT_SEC|sarkar |Editor |MATCH GBR|0_EDT_SEC|sarkar |SEC MT103 |MATCH GBR|0_EDT_SEC|sarkar |AB User |MISSING Both the files are mapped through Organization, Shor_mark. So, based on each Organization, Short_Mark, for each UserName from User.csv, we need to find the Matching and Missing Rolename. I am able to bring Matching records in the output. But really I don't find any concept or logic to achieve "MISSING" records which are present in Master and not in User.csv for each UserName. Please help out guys. Let me know if you need any more information. Note:- In User.csv file, there are n number of Organization, under which n number Shortmark comes which has n number of UserName.
Had any one faced informatica(ETL/Developer), Datawarehouseing interview in UK. Than plz help me (i have any exprience of 3yrs informatica,datawarehousing,oracle,teradata) 1.hw the procedure will b here 2. wht type of question's they will b asking. 3.In which area they concertate more. since this is the first time im facing interview in UK. plz help ASAP.it will b a great help for me thanks to All in Advance
I have id, seq_no date, bill_amt and weight 1,11,'01-Jan-2014',100,2 2,12,'01-Jan-2014',40,5 3,13,'01-Jan-2014',32,5 4,14,'01-Jan-2014',98,2 5,15,'01-Jan-2014',105,3 6,16,'01-Jan-2014',11,3 1,11,'02-Jan-2014',40,2 2,12,'02-Jan-2014',100,5 3,13,'02-Jan-2014',132,5 4,14,'02-Jan-2014',198,2 5,15,'02-Jan-2014',15,3 6,16,'02-Jan-2014',16,3 Now I need output as date MXAMT_LSTWGHT MINAMT_GRTWGHT 01-Jan-2014 100 32 02-Jan-2014 198 100 Could not think of mapping to do so. Please help
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