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CHAPTER 12 Managing System Resources

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.

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