Well, if they are all near the max, half track blocking would result in 2 blocks of 2 records. A 32K block size would result in a block of 3 records, with space for another block of 2 records, but I'm not sure QSAM will do that. And 2.4GB is about 90% of a 3390-3. An average of 7000 or less would be great with 1/2 track blocking, but even the minimum size of 2K for a very simple record you could even just go without blocking without losing much space to inter record gaps.
How about a pattern of some sort on the DSNs. HLQ7.aaaaaaaa.bbbbbbbb.ccccccc.Dyymmdd.Thhmmss, etc. On Thu, Oct 8, 2020 at 11:08 AM Michael Stein <[email protected]> wrote: > > On Wed, Oct 07, 2020 at 07:41:58AM -0400, Joseph Reichman wrote: > > The average number of records in the file could be 240,000 each record > > could be close to 10,000 bytes there are 4,644 files > > So each file could be up to: 10000 * 240000 -> 2.4 GB > > And the maximum total data is: 2.4 GB * 4644 -> 11.14 TB > > Reading 11 TB in 4 hours (?) is: > > 11e12/(4*3600.) -> 763 MB/second > > Most likely all the records are less than the maximum (10K bytes) size > and there is less data that this. > > That's a lot of records too: 240000*4644 -> 1114 million records. > > How long does a billion (1000 million) QSAM GET locates take? > > I have no idea how long a QSAM GET takes. But a billion of them > add up and it's all CPU time. > > What's the blocksize of these datasets? The CPU for each GET > is just bumping a pointer and checking for the end of the current > block. There's more CPU involved in switching blocks. > > I'm still wondering: > > Is this a one time job or recurring every year, month, week, day? > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN -- Mike A Schwab, Springfield IL USA Where do Forest Rangers go to get away from it all? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
