Classic two file match. Sort the two and produce the report. Not a good use of VSAM...
On Sat, Jan 6, 2018 at 2:15 PM, Gerhard Adam <[email protected]> wrote: > Seems a bit round-about. > > Why not REPRO them to a sequential file, sort by key, and then produce > your output. > > > > Sent from my iPhone > > > On Jan 5, 2018, at 4:20 PM, Arun Venkatratnam < > [email protected]> wrote: > > > > Hi All, > > > > We are looking to improve the performance of a COBOL program that > processes 2 VSAM files. The first file is the I/P file and every record > read from the input VSAM file is searched for a matching record in the > other file and a report is written. The program also applies some business > rules while comparing each matching record. > > > > The I/P file is read sequentially while the other file is read in a skip > sequential basis. The test files that were used had 32M records each while > production files have 110M records each. > > > > Attached is the strobe report from the execution of the test job. The > test job takes nearly 7 CPU minutes and was profiled to capture about 1 CPU > minute of execution time. > > > > We are attempting to optimize the VSAM access to these files as it is > seen to take more than 50% of the CPU consumed by this job. > > > > In the 'Attribution of CPU execution time' section, we see that the > major contributors are the components 'QSAM INIT I/O & EXITS' (Module > IGZEQBL) and PARTITION COMMUNICATION. > > > > Could you please help us understand: > > > > 1.What these components are > > 2.Why is QSAM access used instead of VSAM I/O access. > > 3.What needs to be done to reduce the CPU consumption by these > components. > > > > Thank you > > > > Arun > > > > > > ------------------------------------------------------------ > ------------------------------------------------------------ > ------------------------------------------ > > > > 1Strobe* PERFORMANCE PROFILE PROGRAMA > 01/02/2018 PAGE 42 > > > > - #ACE ** ATTRIBUTION OF CPU > EXECUTION TIME ** > > -.COBLIB IGZCPCO IGZEVIO VSAM INPUT/OUTPUT > > ---------------------------WAS INVOKED BY--------------------- > -----------------VIA----------------------- CPU TIME % > > XACTION MODULE SECTION DESCRIPTION > MODULE SECTION DESCRIPTION SOLO TOTAL > > > > .LELIB CEEBINIT LE/370 BATCH INIT/TERM > .32 .32 > > .LELIB CEEBINIT LE/370 BATCH INIT/TERM > IGZEQBL QSAM INIT I/O & EXITS 1.93 1.93 > > > > XACTION MODULE SECTION LOCATION LINE SOURCE TEXT > MODULE SECTION DESCRIPTION > > > > PROGRAMA PROGRAMA 003522 > 1.30 > 1.30 > > > > ----- ----- > > > > 3.55 3.55 > > -.VSAM IDA019L1 VSAM RECORD MANAGEMENT > > ---------------------------WAS INVOKED BY--------------------- > -----------------VIA----------------------- CPU TIME % > > XACTION MODULE SECTION DESCRIPTION > MODULE SECTION DESCRIPTION SOLO TOTAL > > > > .LELIB CEEBINIT LE/370 BATCH INIT/TERM > IGZEQBL QSAM INIT I/O & EXITS 1.84 1.84 > > .LELIB CEEBINIT LE/370 BATCH INIT/TERM > IGZEQBL CURRMEM QSAM INIT I/O & EXITS 4.34 4.38 > > .LELIB CEEBINIT LE/370 BATCH INIT/TERM > IGZEQBL DVFILE QSAM INIT I/O & EXITS .03 .03 > > .LELIB CEEBINIT LE/370 BATCH INIT/TERM > IGZEQBL PREVMEM QSAM INIT I/O & EXITS 22.48 22.51 > > > > XACTION MODULE SECTION LOCATION LINE SOURCE TEXT > MODULE SECTION DESCRIPTION > > > > PROGRAMA PROGRAMA 003522 > IGZCPCO CURRMEM PARTITION COMMUNICATION 4.15 4.19 > > PROGRAMA PROGRAMA 003522 > IGZCPCO IGZEVIO VSAM INPUT/OUTPUT .57 .57 > > PROGRAMA PROGRAMA 003522 > IGZCPCO PREVMEM PARTITION COMMUNICATION 16.80 16.80 > > > > ----- ----- > > > > 50.22 50.32 > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > -- Wayne V. Bickerdike ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
