Sto cercando di capire un esempio nel Capitolo 12 (Elaborazione di query) di Database System Concepts, Sesta edizione.
A relation does not need recursive partitioning if M > nh +1, or equivalently M > (bs/M) + 1, which simplifies (approximately) to M > √ bs .
For example, consider a memory size of 12 megabytes, divided into 4-kilobyte blocks; it would contain a total of 3K (3072) blocks. We can use a memory of this size to partition relations of size up to 3K ∗ 3K blocks, which is 36 gigabytes.
Come sono arrivati a 36 gigabyte?
Inoltre, apprezzo che tu mi possa aiutare a capire il prossimo esempio.
Similarly, a relation of size 1 gigabyte requires just over √ 256K blocks, or 2 megabytes, to avoid recursive partitioning.