IBM Mainframe Forum

Hello,

I know it is not advisable, but out of curiosity - is it possible to "completely empty" a KSDS, 'completely empty' here means removing the control information of the KSDS as well.

Scenario: there is a KSDS which has some records in it, now same has been emptied by using an IDCAMS REPRO with a 'DD DUMMY' INDD statement. Is there a way to end up deleting the control info as well, thereby rendering the KSDS unusable even in OPEN/EDIT/WRITE mode. Corrupting a KSDS is different, what I am referring to is removing the bits themselves which are set/reset depending on the type of access and other similar control info.

And before I get bashed for asking, I know that this is a bad question, though trust me there is good story behind this one.

Thanks.

though trust me there is good story behind this one.

tell us the story so that we can give You a good answer

Hello Enrico,

A fair while back, while emptying out a KSDS using IDCAMS I'd managed to render it unusable. I understand- playing with the KSDS might've corrupted it, would be the plausible conclusion here.
Though I was able to recreate the aformentioned KSDS corruption by using the same JCL, which had a delete/define of KSDS step, and a subsequent IDCAMS/or another utility program for emptying it (it is this step which I am unable to recall, though I am positive on the point that it was an IBM utility program). This same JCL minus the del/def step, when run with a KSDS having data would again yield the same results i.e. not-working-empty KSDS.

It might come as mixing of terminologies here, though, I'd verified LISTCAT of this DS as well, it didn't show anything except for a couple of informational messages (I am unable to recall the same).
File management tools as File-Manager, File-Aid etc, all showed the message- Dataset is Empty, and not the usual - dataset is unusable - message, which is thrown if the dataset is corrupted. The thing to note here is, FM or FA both allow the user to open the dataset in EDIT mode/View mode even if the DS is empty, in this case same wasn't working (message thrown was DS is empty). COBOL file open wasn't working, the usual file-stat '97' was being set, IDCAMS VERIFY kept returning informational message (I am unable to recall them).
Any attempt to write data to this KSDS using IDCAMS REPRO failed with a CC 8.
On searching the web for the reason, what I'd come to understand back then was that I'd somehow managed to remove the file control information; though it didn't make any sense to me as to how this is even possible.

A few days back during a training session I tried recreating the steps, but couldn't work it out as I was unable to recall the program I'd used back then or the informational messages; hence the query that is it even possible to delete the control information of a KSDS using a utility program. This query is only to understand the KSDS organization better; like I'd said earlier, it is indeed a bad question, though out of curiosity; any guidance is much appreciated.

Thanks.

not enough info to continue!

Hello Enrico,

I am sorry, but I really don't have more details, whatever I've written is basis what I could recollect, else I'd have built the JCL and shared the error/info messages post its execution.

Though, just a summary question:

Aki88 wrote:is it even possible to delete the control information of a KSDS

Thanks.

if this dataset has an alternate index you will end up having this problem if you did not deal the alternate first.

Hello Mickeydusaor,

Mickeydusaor wrote:if this dataset has an alternate index you will end up having this problem if you did not deal the alternate first.

The DS is a plain old KSDS, requirement is to break it thereby resulting in similar situation as stated in previous posts.

Thanks.