Limiting the number of cursors, Limiting the number of statements, Lowering a connection’s priority – Sybase 12.4.2 User Manual

Page 470: Prefetching cache pages

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Options for tuning resource use

450

If scrolling cursors are never used in your application, you should make this a
permanent

PUBLIC

option. It will use less memory and make a big

improvement in query performance.

Limiting the number of cursors

The

MAX_CURSOR_COUNT

option specifies a resource governor to limit the

maximum number of cursors that a connection can use at once. The default is
50. Setting this option to 0 allows an unlimited number of cursors.

Limiting the number of statements

The

MAX_STATEMENT_COUNT

option specifies a resource governor to limit

the maximum number of prepared statements that a connection can use at once.

Lowering a connection’s priority

When you set the

BACKGROUND_PRIORITY

option to ON, requests on the

current connection have minimal impact on the performance of other
connections. This option allows tasks for which responsiveness is critical to
coexist with other tasks for which performance is not as important.

Prefetching cache pages

The

SET

option

PREFETCH_BUFFER_LIMIT

defines the number of cache

pages available to Adaptive Server IQ for use in prefetching (the read ahead of
database pages). This option has a default value of 20, which can degrade
multi-user performance. Sybase recommends that you set this option to 0 for
multi-user applications. For more information, see the Adaptive Server IQ
Reference Manual
.

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