IQ Main Store Blocks Message

U#

Number of blocks in use.

#%

Percentage of database filled.

Buffers: U#

Number of buffers in use. Normally this is 100% because the buffer manager leaves buffers in memory until they are needed for some other data. In general, the buffers used and buffers locked numbers are meaningless, because IQ uses buffers as aggressively and efficiently as it can.

This value grows to the maximum number of buffers that fit in the main buffer cache. The number increments whenever a buffer is allocated, but decrements only when a buffer is destroyed, not when it is unlocked or flushed. Objects in the temporary cache release their buffers when they are finished, but in the main cache, IQ may or may not destroy the buffers because as long as a buffer is unlocked, it is available for reuse, whether it is empty, contains data, or contains destroyed data.

L#

Number of locked buffers. A locked buffer is in use and cannot be removed from the cache. IQ locks buffers of some objects, such as hash objects, to keep them in memory. It locks buffers of other objects, such as sorts, depending on the workload and what it considers a fair share for that object.

This number increments whenever you request a buffer. If you exceed the maximum while running a script, the command that exceeds fails and subsequent commands may complete incorrectly.

Buffer locks do not use any memory. A locked buffer has a flag set in the in-memory structure and the flag exists whether or not the buffer is locked.