Configuring the data cache to improve performance

When you install Adaptive Server, it has single default data cache, with a 2K memory pool, one cache partition and a single spinlock.

To improve performance you can add data caches and bind databases or database objects to them:

  1. To reduce contention on the default data cache spinlock, divide the cache into n where n is 1, 2, 4, 8,16, 32 or 64. If you have contention on the spinlock with 1 cache partition, the contention is expected to reduce x/n where n is the number of partitions.

  2. When a particular cache partition spinlock is hot, consider splitting the default cache into named caches.

  3. If there is still contention, consider splitting the named cache into named cache partitions.

You can configure 4K, 8K, and 16K buffer pools from the logical page size in both user-defined data caches and the default data caches, allowing Adaptive Server to perform large I/O. In addition, caches that are sized to completely hold tables or indexes can use relaxed LRU cache policy to reduce overhead.

You can also split the default data cache or a named cache into partitions to reduce spinlock contention.

Configuring the data cache can improve performance in the following ways:

Most of these possible uses for named data caches have the greatest impact on multiprocessor systems with high transaction rates or with frequent DSS queries and multiple users. Some of them can increase performance on single CPU systems when they lead to improved utilization of memory and reduce I/O.