NUMBUFG parameter: Difference between revisions
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If <var>NUMBUFG</var> is specified, no buffer pool buffers are built BTB; all buffers are ATB. Model 204 obtains exactly the <var>NUMBUFG</var> number of buffers. </p> | If <var>NUMBUFG</var> is specified, no buffer pool buffers are built BTB; all buffers are ATB. Model 204 obtains exactly the <var>NUMBUFG</var> number of buffers. </p> | ||
<p> | <p> | ||
<var>NUMBUFG</var> essentially replaces | In this case, <var>NUMBUFG</var> essentially replaces the BTB parameters: <var>NUMBUF</var> and <var>MINBUF</var> are automatically reset to 0, and <var>MAXBUF</var> and <var>SPCORE</var> are ignored. </p> | ||
</li> | </li> | ||
</ul> | </ul> | ||
Revision as of 18:32, 24 August 2016
Number of above-the-bar buffers
Summary
- Default value
- 0
- Parameter type
- System
- Where set
- Not resettable
- Related products
- All
- Introduced
- Model 204 V7.1
Description
Allocate this number of buffer pool buffers above the bar (ATB).
- Prior to version 7.7 of Model 204:
NUMBUFG specifies the number of buffer pool buffers built ATB, while the number of buffer pool buffers built BTB is based on the setting of MINBUF, MAXBUF, and SPCORE.
- As of version 7.7:
If NUMBUFG is specified, no buffer pool buffers are built BTB; all buffers are ATB. Model 204 obtains exactly the NUMBUFG number of buffers.
In this case, NUMBUFG essentially replaces the BTB parameters: NUMBUF and MINBUF are automatically reset to 0, and MAXBUF and SPCORE are ignored.
The maximum number of buffers is 2**31/3, or 715,827,882, which limits buffer pools to 4.2 terabytes or less.
The minimum number of ATB buffers is:
NLRUQG * ((NSERVS + NSUBTKS) * MAXOBUF + 15)
If you set NUMBUFG to a lower value, it is reset to the calculated value.
See also
For more information about setting NUMBUFG, see Managing ATB storage with NUMBUFG.