+1 That makes everything clear. Thank you very much, P.; this explanation was exactly what I want to get...
Am 16.01.2015 um 07:33 schrieb P.H.:
> hope someone can help. I try to understand how a SMF RDW works.
> Basically I have no problems to understand ?the whole thing?
> as long as the record is not ?spanned?. To make it clearer:
> For example a RDW (first 4 Bytes) of ?33.14.01.00?.
> OK, x?3314? tells me that the record is 13.076 Bytes long,
> but how to deal with the remaining part the ?0100?? The only thing I know is
> that the record is spanned actually. Does this mean that the next 256 Bytes ?after?
> the first 13.076 Bytes belong together or how is this
> RDWs are 4 bytes. The first two are always the lenght of the record. The fourth
> byte is reserved and is always x'00'. The third byte, the one you're talking
> about, is always x'00' unless the record format is VBS, .i.e. spanned records.
> With non spanned records, a logical record must always fit into a single
> block. For spanned format, the logical records may be split into multiple parts,
> each one being written to a separat block. So, there is a first part, there are
> zero or more intermiediate parts, and there is a final part. The rightmost 2
> bits of the third byte in the RDW indicat just this:
> x'01' -> first part, .i.e. a new spanned record starts here.
> x'11' -> intermediate part. Note that there is no sequence number. The sequence is given by
> the sequence of the blocks.
> x'10' -> The final part, .i.e. the end of the spannded record.
> Note that even with spanned format, non-spanned records are allowed besides
> spanned records. I.e. there may be records that do fit in a block, and they will
> have the third byte as x'00'.