Serialization and header values 0xFF 0x01

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https://learninghub.kx.com/forums/topic/serialization-and-header-values-0xff-0x01

I'm currently looking at a pair of bytes which define a header in some code which is related to KDB serialization format.

The byte sequence is 0xFF, 0x01.

Does anyone know what this might mean?

This could be a red-herring, in that the code I am looking at might be a modified version of the KDB specification. So it is possible this byte sequence is not related to any KDB specification.

Thanks in advance

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This is very little to go on. You could check the official documentation of the IPC protocol at Interprocess communication | Developing | kdb+ and q documentation - kdb+ and q documentation. A Python implementation supporting protocol version 6 is qPython/qpython/qreader.py at main · finos/qPython · GitHub.

If this is about on-disk serialization, that format is not documented and the only supported way to read it is to launch a q process and use the built-in function `get`.

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It may be exclusively related to on-disk serialization. If that process is not documented then perhaps it is the case that KDB simply writes this combination of bytes as a header.

Thanks for the link. I read through some similar pages earlier but couldn't find anything which seemed relevant.

I do recall seeing something at some point which looked like it might have been part of a header specification. It may even have been this page which you link above. But I didn't see any values which would match up with 0xff 0x01. I'm not sure exactly what that page was.