GRANDSYSTEME.COM: SITE DE RESSOURCES MAINFRAME

 

QSAM

LANGUE TYPE DOCUMENT NB URL
ENGLISH
HTML 3

QSAM - ENGLISH

QSAM - ENGLISH - HTML

www.cs.niu.edu
Queued Sequential Access Method
QSAM Example
www.simotime.com
The VSAM-QSAM Connection
MOTCLE ABBREVIATION DESCRIPTION
Basic Sequential Access Method BSAM The simplest data set on an IBM mainframe. A sequential file access method for reading, writing and updating sequential data sets and partitioned data set members. For additional information refer to the QSAM definition in this glossary> or http://www.simotime.com/indexsam.htm>
BSAM Basic Sequential Access Method. One of two access methods used to read and write sequential datasets in z/OS. A part of DFSMSdfp. See also QSAM.
ESDS Entry Sequenced DataSet. VSAM sequential dataset in which the data is held in the order in which it was originally entered (i.e., new records are placed on the end of the dataset). Can be used as a replacement for BSAM and QSAM in z/OS. But most commonly used as a replacement for sequential datasets in VSE/ESA. See also Linear dataset.
hierarchical sequential access method HSAM An IMS HS organization that is used for sequential storage and access of segments on tape or direct access storage. BSAM and QSAM are used as the basis for HSAM
non-VSAM data set A data set allocated and accessed using one of the following methods: basic direct access method (BDAM), basic partitioned access method (BPAM), basic indexed sequential access method (BISAM), basic sequential access method (BSAM), queued sequential access method (QSAM), or queued indexed sequential access method (QISAM)
QSAM queued sequential access method
QSAM Queued Sequential Access Method. One of the original OS/360 file access methods still used today in z/OS for reading and writing sequential datasets. BSAM is a less commonly used alternative.
QSAM See queued sequential access method
queued sequential access method QSAM An access method for storing and retrieving logical records in a continuous sequence. Input data blocks awaiting processing or output data blocks awaiting transfer to auxiliary storage are queued on the system to minimize delays in I/O operations
queued sequential access method QSAM An extended version of the basic sequential access method (BSAM). Input data blocks awaiting processing or output data blocks awaiting transfer to auxiliary storage are queued on the system to minimize delays in I/O operations
queued sequential access method QSAM m?thode d'acc?s fichier s?quentielle, extension de BSAM, caract?ris?e par le buffering
queued sequential access method QSAM An extended version of the basic sequential access method (BSAM). When this method is used, a queue of data blocks is formed. Input data blocks await processing, and output data blocks await transfer to auxiliary storage or to an output device
queued sequential access method QSAM An extended version of BSAM. When this method is used, a queue is formed of input data blocks awaiting processing or processed output data blocks awaiting transfer to auxiliary storage or to an output device
Queued Sequential Access Method QSAM A replacement or an extended version of the basic sequential access method (BSAM). With this method a queue is formed of input data blocks that are awaiting processing or of output data blocks that have been processed and are awaiting transfer to auxiliary storage or to an output device. This typically provides better performance because the application is not waiting for the physical reads or writes to and from the Input or Output devices. For additional information refer to the BSAM definition in this glossary> or http://www.simotime.com/indexsam.htm>
SAM Sequential Access Method. Method of reading sequential datasets ? from the beginning to the required record. Originally a collective term for QSAM and BSAM, when the situation applied to both. But SAM grew to include SAM-E in 1983 with the announcement of DFP, now DFSMSdfp. See also ESDS.