Table of Contents
- 1 Can we open empty VSAM file?
- 2 How do I check if a VSAM is empty?
- 3 In which cluster type are records added at the end of the data set?
- 4 How do I view VSAM files?
- 5 How do I check VSAM properties?
- 6 Is it possible to delete records from ESDS?
- 7 How to check VSAM file status in I-0 mode?
- 8 Can a VSAM file that has never contained data be read?
Can we open empty VSAM file?
A VSAM file that has never contained a record is treated as unavailable. An empty file can be opened for output only. When you open for output, COBOL will write a dummy record to the file and then delete it our.
How do I open an empty Ksds file in Cobol?
To open a file that has never contained records (an empty file), use a form of the OPEN statement. Depending on the type of file that you are opening, use one of the following statements: OPEN OUTPUT for ESDS files. OPEN OUTPUT or OPEN EXTEND for KSDS and RRDS files.
How do I check if a VSAM is empty?
By using IDCAMS repro also empty check can be done. If the return code is 4 (RC=4), then the file is empty. 3. If the return code is Zero (RC=0) then file is not empty otherwise it is empty and return code would be 12 if it is empty .
How do I open a VSAM file in mainframe?
Loading a VSAM data set with access method services: You can load or update a VSAM data set by using the access method services REPRO command. Use REPRO whenever possible….To initially load a VSAM file:
- Open the file.
- Use sequential processing ( ACCESS IS SEQUENTIAL ).
- Use WRITE to add a record to the file.
In which cluster type are records added at the end of the data set?
Records in ESDS cluster are stored in the order in which they were inserted into the dataset. Records are referenced by physical address which is known as Relative Byte Address (RBA).
How does Cobol handle empty files?
When u try to read an empty input file then the file-status will be NON ZERO (i.e) 35. so check the file status if it is ’35’ then u read an empty input file. Then abort or do the exception wat ever u need. Be carefull with “empty files” on the mainframe.
How do I view VSAM files?
We use FILEAID to view a VSAM file. Type FA on the command prompt and see if it is available in your shop.
How do you check if a file is empty or not in JCL?
EMPTY File condition check using JCL utilities
- Empty File check using – ICETOOL.
- Empty File check using – FILEAID.
- Empty File check using – IDCAMS.
- Allocate New File.
- Empty Existing File.
How do I check VSAM properties?
LISTCAT command in VSAM is used to view the properties of VSAM file like volume details, space details, path details, and catalog details. LISTCAT can list many properties like cluster, data, index, spae details, history, volume and much more.
How do you transfer VSAM data to VSAM?
Easiest way to copy an existing VSAM file to a new VSAM file is by using FILE-AID. Go to FILE-AID —> then go to option 3 —> From there again go to option 3 , which is FILE-AID COPY Utility. At this panel u have to supply FROM dataset info , which is ur old existing VSAM dataset.
Is it possible to delete records from ESDS?
Records can never be deleted from an ESDS. To delete a single record in a KSDS or RRDS, use one of these three methods: Retrieve it for update with a READ UPDATE command, and then issue a DELETE command without specifying the RIDFLD option.
Which is the base VSAM cluster?
Q15) What is the base cluster? Q15) The base cluster consists of the data component and the index component for the primary index of a KSDS.
How to check VSAM file status in I-0 mode?
After reading a record from a Vsam file which is opened in I-0 mode. I am checking ‘Valid key’ (file status :22) and ‘Not valid key’ (file status:23). do we need to check any other filestatus other than above file status? similarly after writing a record into Vsam file , is it enough to check file status ’00’ for successful write operation?
When to open or close a VSAM file?
If open mode is I-O or EXTEND, then file will be created. 07 Open or Close statement is executed with a phrase that implies a tape file (ex NO REWIND) whereas the file is not in TAPE. 12.optional file that is not present.
Can a VSAM file that has never contained data be read?
Any VSAM file that has never contained data cannot be successfully READ. If a VSAM file contained data at some point in the past (i.e. records were written to it) and that data was later deleted, you could successfully READ the file but you would encounter an EOF condition on the 1st READ (SC=10).