zVSAM V2 - Logical processes for RPL-based requests
This document describes the logical processes for RPL-based requests to be implemented in zVSAM V2.
RPL macro
GENCB RPL macro
MODCB RPL macro
SHOWCB RPL macro
TESTCB RPl macro
POINT macro
Prefix counter field CTRNEXCP needs to be incremented whenever a block is needed that does not yet reside in a buffer.
If buffers need to be written out to make room for a block that needs to be read, then the CTRNEXCP counter needs to be incremented as well.
Prefix counter field CTRNRETR needs to be incremented for every block accessed, whether it needs to be read,
or already resides in a buffer does not matter for this count field.
If buffers need to be written out in order to allocate a buffer for a block that needs to be read, then prefix counter CTRNNUIW needs to be incremented.
GET macro
Prefix counter field CTRNEXCP needs to be incremented whenever a block is needed that does not yet reside in a buffer.
If buffers need to be written out to make room for a block that needs to be read, then the CTRNEXCP counter needs to be incremented as well.
Prefix counter field CTRNRETR needs to be incremented for every block accessed, whether it needs to be read,
or already resides in a buffer does not matter for this count field.
If buffers need to be written out in order to allocate a buffer for a block that needs to be read, then prefix counter CTRNNUIW needs to be incremented.
PUT macro
Prefix counter field CTRAVSPAC must be updated. When consuming free space to allocate a new record, reduce CTRAVSPAC with space consumed.
When allocating a new block (or splitting an existing block) add the blocksize – (block header, block footer, RPTR area)
and reduce with amount used up (record length, including RDW/SDW and RPTR). When lengthening a record, subtract the difference;
when shortening a record, add the difference.
Prefix counter fields CTRHALCRBA and CTRENDRBA should be updated whenever a record is added beyond the current value of these fields.
CTRENDRBA also should be updated in case the last record in the component is lengthened.
Prefix counter field CTRNCIS should be incremented whenever a block needs to be split.
Prefix counter field CTRNEXCP needs to be incremented whenever a block needs to be written out.
This occurs when the cluster was opened with MACRF=NDF. With MACRF=DFR no writes are forced and no EXCP needs to be counted.
When a file can no longer be extended a secondary file needs to be allocated. When that is done transparently, CTRNEXT needs to be incremented.
Setting its initial value is a function of zRepro.
Prefix counter fields CTRNINSR and CTRNLOGR need to be incremented whenever a new record is added to the component.
Prefix counter field CTRNRETR needs to be incremented for every block accessed, whether it needs to be read,
or already resides in a buffer does not matter for this count field. For basic put operation this is irrelevant,
but for updating an index or an AIX reads may be needed and should be counted for the component being read.
When an existing record is updated, then CTRNUPDR needs to be incremented.
When adding a record the record length (including SDW/RDW, but excluding RPTR) needs to be added to the prefix counter field CTRSDTA.
When a record is updated to a different length, then the difference in length needs to accounted into the CTRSDTA field.
When a user write is forced then the prefix counter field CTRNUIW needs to be incremented. This happens when a put is issued to a cluster
that was opened with MACRF=NDF. For clusters opened with MACRF=DFR writing is done by zVSAM when the buffer is needed for a different block.
These writes are counted in the CTRNNUIW field.
The prefix counter field CTRAVGRL contains the value of CTRSDAT / CTRNLOGR rounded up to nearest integer.
The field should be updated whenever either or both of the input values are changed.
The prefix counter field CTRLOKEY@ points to a value of PFXKEYLN bytes.
The value should be updated whenever a record is inserted that has a lower key than the current lowest key.
ERASE macro
Prefix counter field CTRNDELR should be incremented for every successful erase operation.
Prefix counter field CTRNEXCP needs to be incremented whenever a block is needed that does not yet reside in a buffer.
If buffers need to be written out to make room for a block that needs to be read, then the CTRNEXCP counter needs to be incremented as well.
Prefix counter field CTRNLOGR needs to be decremented for every successful erase operation.
Prefix counter field CTRNRETR needs to be incremented for every block accessed, whether it needs to be read,
or already resides in a buffer does not matter for this count field. For basic erase operation this is irrelevant,
but for updating an index or an AIX reads may be needed and should be counted for the component being read.
When erasing a record the record length (including SDW/RDW, but excluding RPTR) needs to be subtracted from the prefix counter field CTRSDTA.
When a user write is forced then the prefix counter field CTRNUIW needs to be incremented.
This happens when an erase is issued to a cluster that was opened with MACRF=NDF.
For clusters opened with MACRF=DFR writing is done by zVSAM when the buffer is needed for a different block.
These writes are counted in the CTRNNUIW field.
The prefix counter field CTRAVGRL contains the value of CTRSDAT / CTRNLOGR rounded up to nearest integer.
The field should be updated after every successful erase operation.
The prefix counter field CTRLOKEY@ points to a value of PFXKEYLN bytes.
The value should be updated whenever the record is erased with the current lowest key.
CHECK macro
ENDREQ macro
VERIFY macro
Prefix counter field CTRNEXCP needs to be incremented whenever a block is needed that does not yet reside in a buffer.