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On IBM mainframes, BatchPipes is a batch job processing utility which runs under the MVS/ESA operating system and later versions—OS/390 and z/OS.〔http://www-01.ibm.com/common/ssi/cgi-bin/ssialias?infotype=an&subtype=ca&appname=Demonstration&htmlfid=897/ENUS200-093 〕 ==Core function== In traditional processing, if data records are written out to sequential (QSAM and BSAM) data set on disk or tape, they cannot be read concurrently by another job. The "writer" and "reader" cannot run at the same time. This is termed ''file-level interlock'' or ''data-set-level interlock''. With BatchPipes an installation can arrange for the data to be "piped" between the two jobs. The advantage is that the jobs can run concurrently and it is possible, and very usual, to avoid the time to write the data to secondary storage and to read it back. The combination of these two characteristics, if used judiciously, leads to a reduction in the combined elapsed time of the two jobs, as measured from the start of the writer job to the end of the reader job. BatchPipes maintains a ''short'' queue of records being passed between the writer and the reader. The writer adds records to the back of the queue and the reader takes them from the front. This is deemed ''record-level interlock'' and allows the reader and the writer to run concurrently. A sort is a special case: ''all'' the input records must be read before the first output record can be written. Hence there can be no overlap between the input and output phases of a sort. But the input phase ''can'' be overlapped with the previous job's output phase. Similarly, the output phase of sort can be overlapped with a downstream job that reads the sorted data. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「BatchPipes」の詳細全文を読む スポンサード リンク
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