Sequential Assignment

Table-lock spinlocks, configured by the table lock spinlock ratio parameter, use the sequential assignment method.

The default configuration for table lock spinlock ratio is 20, which assigns 20 rows in an internal hash table to each spinlock. The rows are divided up sequentially: the first spinlock protects the first 20 rows, the second spinlock protects the second 20 rows, and so on.

In theory, protecting one resource with one spinlock provides the least contention for a spinlock and results in the highest concurrency. In most cases, the default value for these spinlock ratios is probably best for your system. Change the ratio only if there is spinlock contention.

Use sp_sysmon to get a report on spinlock contention. See Performance and Tuning Series: Monitoring SAP Adaptive Server with sp_sysmon.