Interested to Buy Any Domain ? << Click Here >> for more details...
what is the difference between adding keys & constraints
into a phisical file
- 6 Answers
- 15271 Views
- HSBC, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / jherie
A key field defines the order in which the records of a PF
member will be sorted (ascending or descending).
On the other hand, constraints, such as UNIQUE, defines
which key field values or records are valid/allowable to be
written into a file. UNIQUE prevents a record with
duplicate key field values to be written into a PF.
| Is This Answer Correct ? | 25 Yes | 0 No |
Answer / sweety joy
during the time of compilation of a file , constrains are
being removed, from the file .but at the time of
compliation keys are not removed in case from pf.
constraints has no affects on members of a pf but keys has
affect on members of pf
| Is This Answer Correct ? | 2 Yes | 2 No |
Answer / kkcode400
ADDING KEY FIELDS TO FILE IT DOES NOT CHECK THE EXISTING
DATA.
BUT CONSTRAINS CHECK THE EXISTING DATA BEFORE ADDING IT.
IF ANY DUPLICATE KEY VALUES ARE THERE OPERATION FAILURE.
| Is This Answer Correct ? | 1 Yes | 1 No |
Answer / kolla ravi
Primary Key - Unique Key - Key are all possible with DDS.
Either a primary or a Unique key as required can be setup
with UNIQUE keyword at file level in DDS.These keys Do not
allow any two records with same keys.
When UNIQUE is not used then FIFO or LIFO may be used. When
nothing is specified it is understood to be FIFO.
All these need Key fields to be specified.
And in addition to this whether primary/unique or just a
key, a key field dictates the order of retrieval of records
when programs read the files.
All these what we spoke above is done through DDS. That
is : all these stay right within the object.
On the other hand it is possible to setup Constraints
externally. These being Primary/Unique/Referetinal/Check.
Once these are defined they can be controlled Externally by
enabling, Disabling or removing them on the files for which
they are defined.In this context it is worth while
understanding various states of constraints and Upd/delete
rules in this context.
| Is This Answer Correct ? | 0 Yes | 1 No |
Answer / praseetha sandeep
when we add keys in a pf it has effect only in that
particular field of pf but when we add constrains to a pf it
has an effect to entire pf
| Is This Answer Correct ? | 3 Yes | 5 No |
Answer / suju
constraint wl effect the particular field,key wl effect the
whole pf.
| Is This Answer Correct ? | 1 Yes | 7 No |
pls anyone explain about compile time array,pre run time array run time array
How we can't update join logical files?
what is open data path? and what is the diff b/w access path and open data path?
How to know logical file belongs to which physical file without source?
wirte a simple program for read file in cl
what is the difference between adding keys & constraints into a phisical file
how to update physical files using normal logical file
I have physical file with 100 records,there is no any duplicate records in this pf.based on this pf one logical file I have used.but this lf is viewing only 80 records only of that pf?what is the reason for this?
Suppose I have a pf, it contains 5 members, how to access particular member data from logical file? What is the use of member in pf?
How to retrieve a physical file after deleting that ? what is keyword used for that....??
how can we write LF using flatfile.
How to find the list of source physical files in a library?
RPG400 
