Parameters in this group specify properties in a named cache. Each configured data cache on the server has this block of information in the configuration file. In this case, c_log is the configuration file entry for a separate named cache for log devices.
The Named Cache:c_log section, including the
related [4K I/O Buffer Pool] and [16K
I/O Buffer Pool] sections, is not included in
the default ASE configuration file and must be added to your configuration
file. Use a text editor to cut this section from the RAP_ASE_Server.cfg configuration
file included with Risk Analytics Platform and paste it into your
own configuration file.
[Named Cache:c_log] cache size = 800M cache status = log only cache status = HK ignore cache cache replacement policy = DEFAULT local cache partition number = 1
cache size = 800M The value of 800M is a good size for the RAP sample database. This option is tunable.
cache status = log only This named cache is used only for the log.
cache status = HK ignore cache Setting this option equal to HK ignore cache prevents the housekeeper process from washing the log cache and avoids contention between the housekeeper and cache manager spinlock.
local cache partition number = 1 The value of 1 is the standard recommendation for this option and specifies 1 partition for the cache.
[4K I/O Buffer Pool] pool size = DEFAULT wash size = DEFAULT local async prefetch limit = 0
local async prefetch limit = 0 The value of 0 disables prefetch activities, which are not needed.
[16K I/O Buffer Pool] pool size = 780M wash size = DEFAULT local async prefetch limit = 0
pool size = 780M The value of 780M is a starting point. The remainder of the 800M is allocated to the 4K pool. When changing cache size, give the most to the 16K buffer pool, because the log I/O size is set to 16K for the databases using this pool. This option is tunable and should be increased if necessary.
local async prefetch limit = 0 The value of 0 disables prefetch activities, which are not needed.
