Local cache misses that hit in the server cache avoid expensive
disk accesses.
--the assumption that a random
disk access will be required for each record identifier for each term, as if inverted lists were stored as a linked list on disk (They should be stored contiguously or at the very least in a linked list of blocks.);
The speed of the individual work stations will play a role, the power of the file server's processor and its clock speed, together with the speed of hard
disk access are all important factors when considering the hardware.
They include: (1) the inability to use disk caching routines such as SmartDrive, which really slows
disk access; (2) much slower disk defragmenting - over an hour to defrag a compacted disk vs.
Running Speed Disk keeps the hard
disk access time from slowing down by correcting the file fragmentation that occurs with use.
DOS keeps track of where everything is located, but one result is to slow
disk access time considerably.
Speeding transmissions and
disk access time, compression creates smaller files, yielding the equivalent of 20 to 50 times more color image storage capacity than with uncompressed image data, according to Nikon.
Ideally, he says, laptop software should only require
disk access when the program loads or when the user saves data.
Then the time elapsed for each activity such as processing,
disk access, etc., is plugged into the formula in order to determine cost per unit of service provided.
CACHING AND OTHER
DISK ACCESS AVOIDANCE TECHNIQUES ON PERSONAL COMPUTERS Disk caching is a technique for keeping the most recently used disk blocks in an associative memory in main storage, with the expectation that those blocks will be used again in the near future.