SERVSIZE parameter: Difference between revisions
m (→Handling SQL statements greater than 32K bytes: add small clarification) |
m (typo) |
||
| Line 17: | Line 17: | ||
==Description== | ==Description== | ||
<p> | <p> | ||
The size of the server area to be allocated, rounded up to a multiple of the smallest operating system page size. | The size of the server area to be allocated, rounded up to a multiple of the smallest operating system page size. So, for example, an Online with servers set to 750000 will show 753664 (the next highest multiple of the 4096 page size) under z/OS.</p> | ||
<p> | <p> | ||
<var>SERVSIZE</var> must not be a negative number. If the default value | <var>SERVSIZE</var> must not be a negative number. If the default value is used, the server area allocated is exactly large enough to contain the tables for the user specified on the same parameter line. If a positive value less than <var>[[FIXSIZE parameter|FIXSIZE]]</var> (user's fixed size) is specified, <var class="product">Model 204</var> increases the value so that the server area allocated is large enough to hold the user's fixed size. </p> | ||
<p> | <p> | ||
In a <var class="product">Model 204</var> run that uses server swapping (the typical case for | In a <var class="product">Model 204</var> run that uses server swapping (the typical case for Online runs), the size of each server is likely to be limited by the physical device used for swapping. </p> | ||
<ul> | <ul> | ||
<li>When a CKD device is used for swapping, server size is limited to the device's cylinder size. </li> | <li>When a CKD device is used for swapping, server size is limited to the device's cylinder size. </li> | ||
Revision as of 23:04, 10 August 2016
Maximum size of this server
Summary
- Default value
- 65536 as of version 7.7 (and zap maintenance in 7.6, 7.5, and 7.4); formerly, 0
- Parameter type
- Server
- Where set
- View only; set on first NSERVS user's parameter lines
- Related products
- All
- Introduced
- Model 204 V6.1 or earlier
Description
The size of the server area to be allocated, rounded up to a multiple of the smallest operating system page size. So, for example, an Online with servers set to 750000 will show 753664 (the next highest multiple of the 4096 page size) under z/OS.
SERVSIZE must not be a negative number. If the default value is used, the server area allocated is exactly large enough to contain the tables for the user specified on the same parameter line. If a positive value less than FIXSIZE (user's fixed size) is specified, Model 204 increases the value so that the server area allocated is large enough to hold the user's fixed size.
In a Model 204 run that uses server swapping (the typical case for Online runs), the size of each server is likely to be limited by the physical device used for swapping.
- When a CKD device is used for swapping, server size is limited to the device's cylinder size.
- When an FBA device is used, server size is limited by the amount of virtual memory available to Model 204.
- All servers defined for the run, along with many other blocks of storage, must fit in virtual memory.
- In a run that does not use server swapping (the typical case for batch runs), the servers for all users in the run must fit in virtual memory.
For a description of how the sizes of the fixed table and the variable table are calculated, see Sizing user server areas.
Handling SQL statements greater than 32K bytes
When handling an SQL statement that is greater than 32K, you must consider the SERVSIZE parameter: If its value is not large enough, the error message invoked includes the name of the relevant parameter whose value needs to be increased (LSTBL, LNTBL, etc.).