The queued access methods provide three processing modes (move, data, and locate mode) that determine the extent of data movement in virtual storage. Move, data, and locate mode processing can be specified for either the GET or PUT macro. (Substitute mode is no longer supported; the system defaults to move mode.) The movement of a record is determined by the following modes.

Move Mode. The system moves the record from a system input buffer to your work area, or from your work area to an output buffer.

Data Mode (QSAM Format-V Spanned Records Only). Data mode works the same as the move mode, except only the data portion of the record is moved.

Locate Mode. The system does not move the record. Instead, the access method macro places the address of the next input or output buffer in register 1. For QSAM format-V spanned records, if you have specified logical records by specifying BFTEK=A or by issuing the BUILDRCD macro, the address returned in register 1 points to a record area where the spanned record is assembled or segmented.

PUT-Locate Mode. The PUT-locate routine uses the value in the DCBLRECL field to determine if another record will fit into your buffer. Therefore, when you write a short record, you can get the largest number of records per block by modifying the DCBLRECL field before you issue a PUT-locate to get a buffer segment for the short record. Perform the following steps:

1. Record the length of the next (short) record into DCBLRECL.
2. Issue PUT-locate.
3. Move the short record into the buffer segment.

GET-Locate Mode. Two processing modes of the PUTX macro can be used with a GET-locate macro. The update mode returns an updated record to the data set from which it was read. The output mode transfers an updated record to an output data set. There is no actual movement of data in virtual storage. See z/OS DFSMS Macro Instructions for Data Sets for information about the processing mode specified by the parameter of the PUTX macro.