rampratap409

 Profile Answers by rampratap409 Questions by rampratap409

• Oct 9th, 2006

 

1.What is bulk collect?

Bulk collect is part of PLSQL collection where data is stored/ poped up into a variable.

example:

declare

type sal_rec is table of number;

v_sal sal_rec;

begin

select sal bulk collect into v_sal from emp;

for r in 1.. v_sal.count loop

dbms_output.put_line(v_sal(r));

end loop;

end;

2.What is instead trigger

instead triggers are used for views.

3.What is the difference between Oracle table & PL/SQL table?

Table is logical entity which holds the data in dat file permanently .  where as scope of plsql table is limited to the particular block / procedure .  refer above example  sal_rec table will hold data only till programme is reaching to end;

4.What R built in Packages in Oracle?

There R more then 1000 oracle builtin packges like:

Dbms_output,  dbms_utility    dbms_pipe .............

 

5.what is the difference between row migration & row

changing?

Migration: The data is stored in blocks whic use Pctfree 40%

and pctused 60% ( normally). The 40% space is used for update and delete statements .  when a condition may arise that update/delete statement takes more then pctfree then it takes the space from anther block.  this is called migration.

RowChaining: while inserting the data if data of one row takes more then one block then this row is stored in two blocks and rows are chained.

shashank.G

• Oct 13th, 2006

 

insted of triggers: They provide a transparent way of modifying view that can't be modified directly through SQL,DML statement.

rampratap409

 Profile Answers by rampratap409 Questions by rampratap409

• Oct 13th, 2006

 

Hi Shashank,

Can you explain instead off trigger, DML Trigger and views.

.

askvenki

 Profile Answers by askvenki 

• Jul 20th, 2007

 

rowchaining works for varchar2 datatype which will allocate memory dynamically
suppose thier is column name varchar2(20);

first value-- venki which is 5
changed to venki12? which is 7

then? oracle will create datablock for 2 extra spaces.so while querying it must read data from two blocks. so performance is less for varchar2