Sybase 12.4.2 - Manual (Page 471)

CHAPTER 12 Managing System Resources
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Optimizing for typical usage
Adaptive Server IQ tracks the number of open cursors and allocates memory
accordingly. In certain circumstances,
USER_RESOURCE_RESERVATION
option can be set to adjust the minimum number of current cursors that IQ
thinks is currently using the product and hence allocate memory from the
temporary cache more sparingly.
This option should only be set after careful analysis shows it is actually
required. Contact Sybase Technical Support with details if you need to set this
option.
Other ways to improve resource use
This section describes several ways to adjust your system for maximum
performance or better use of disk space.
Restricting database access
For better query performance, set the database to read-only, if possible, or
schedule significant updates for low usage hours. Adaptive Server IQ allows
multiple query users to read from a table while you are inserting or deleting
from that table. However, performance can degrade during concurrent updates.
Disk caching
Disk cache is memory used by the operating system to store copies of disk
blocks temporarily. All file-system based disk reads and writes usually pass
through a disk cache. From an application’s standpoint, all reads and writes
involving disk caches are equivalent to actual disk operations.