Hybrid Hash Join (cont)
Some observations:
- with k partitions, each partition has expected size ceil(bR/k)
- holding 1 partition in memory needs ceil(bR/k) buffers
- trade-off between in-memory partition space and #partitions
Other notes:
- if N = bR+2, using block nested loop join is simpler
- cost depends on N (but less than grace hash join)
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