What blksize should be used for 1/2 track blocking on the Datano2 buffers?
Article ID: 124612
Updated On:
Products
Issue/Introduction
In the REDCENTRIC CTC presentation CTC07W1 & 2, it is recommended switching DATALN2 to 1/2 blocking for performance reasons. We currently use DATALN=4K and DATALN2=8K. If we were to switch to DATALN2 to being 1/2 track blocking,
what should we use for the proper blksize? 28,332 or 24,576 or something else. Most of our tables using DATALN2 also have DB Compression on them.
Environment
Datacom/DB 15.0
Resolution
Per IBM:
".... to maximize use of a 3380 track, 98.9% of the space available on a track can be used by writing two records of 23476 bytes each. The most efficient block size for the 3390 would be 27998 bytes; two of these blocks would fit on a 3390 track."
This is the blocksize (27998) we use to INIT FXX/LXX.
It is also the blocksize that you can use when setting DATAPOOL or other BUFFER Pools .
Like DATAPOOL 27998,2000
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