When i issue a select statement, i find the number of buffers in FLRU does not get reduced though the select statement fetches some number of datapages from the disk. I want to know how does informix allocate buffers for Select Statements. Does it treat the buffers allocated for the Select statements as Free.
Most software-systems are "lazy." (By design.) If there's no pressure on a buffer pool then why clean it up? If you read the data before and you know it's still good, why read it again? If you need a buffer what difference does it make if you recycle or grow the pool? There's an eternal rule in data-processing: "Speed or Space." Minimzing the size of buffer-pools (or the amount of "free RAM" in a virtual-memory system) is simply not a priority; especially since the memory is virtual and will be paged-out anyway if pressure actually develops on the OS.