On Fri, Mar 19, 2021 at 03:35:39PM -0400, Joseph Reichman wrote: > So this is what I will do > > I’ll do 3 reads in the first since i need to get myself going I’ll issue the > WAIT using the ECB from the DECB
Limiting the pending reads to 3 will limit the performance to worse (or at least no better) than QSAM. You did set NCP to a value at least high enough for the number of pending READs you would have at any time, right? Also keep in mind that you need to issue the wait/check on the DECBs in exactly the same order as you did the READs. See the section "Using Overlapped I/O with BSAM" in DFSMS Using Data Sets (in Chapter 22 Accessing Records). > Than when I finish processing that buffer and need to go to the second > I/O I’ll issue a WAIT for that Unless you are reading multple files (multiple DCBs) at once (each with their own group of pending READs) issuing WAIT before CHECK is just wasted effort/CPU time. This is because you have to issue the CHECKs for each DCB in the order you did the READs and they will complete in that order. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
