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 |
Hi, I want to change date type char value integer value? I tried alter table tab_name modify (newcolumn newdatetype). But The columns have 10 million values(char type) so I want to load now numeric data. How it is possible? Old Values New Value(I want to load numeric data but the old value should be there in the column) Y 1 N 0 ERROR at line 1: ORA-01439: column to be modified must be empty to change datatype Please help on this. Thanks, GM
Can you use one mapping to populate two tables in different schemas
what happens when a batch fails?
How to add source flat file header into target file?
i have a session which creates a file every time when i runs the session, but it replaces the first file with second file,i want to append the second file follwed by first file when i runs the session,how to achieve this?
What is a filter transformation?
what is meant by data driven.. in which scenario we use that..?
i have f;latfile source. i have two targets t1,t2. i want to load the odd no.of records into t1 and even no.of recordds into t2.
What all are steps in up gradation of Informatica server?
Hi Everybody, I have one fixed width file as source and 4 oracle tables (relational) as target. What are the Unit test cases i need to implement ? 1.Using TextPad software i tested postion of the field 2.As per specification i tested like whether it is correctly mapped or not? Is there any other test case do i need to implement. If possible can any one give me the test cases Advance Thanks
when i try to connect to the repository server i am getting this message can someone help me.. Starting Repository [infa_rep] (6016|1292) Informatica Repository Agent, version [7.1.1], build [0811], 32-bit. (6016|1292) Copyright (c) 2000-2004 Informatica Corporation. All Rights Reserved. This Software is protected by U.S. Patent Numbers 6,208,990; 6,044,374; 6,014,670; 6,032,158; 5,794,246; 6,339,775 and other U.S. Patents Pending. (6016|1292) Informatica Repository Agent starting up. (6016|1292) Security audit trail has been turned off. (6016|1292) infa_rep: Repository runtime manager initialized. (6016|1292) infa_rep: Initialized configuration information. (6016|1292) infa_rep: Initialized request dispatcher. (6016|1292) Database Connection Error : Failed to logon to Database server ORA-12154: TNS:could not resolve service name Database driver error... Function Name : Connect Database Error: Failed to connect to database using user [] and connection string []. (6016|1292) Service stopped.
write sql query vertical to horiozontal following table id name 1 100 2 dinesh 3 india 1 101 2 suresh 3 india 1 103 2 prakesh 3 usa i want output like id name country 100 dinesh india 101 suresh india 103 prakesh usa