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add empirically determined estimators of c0 size, and pessimistic ones that are the default

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git-svn-id: svn+ssh://svn.corp.yahoo.com/yahoo/yrl/labs/pnuts/code/logstore@1589 8dad8b1f-cf64-0410-95b6-bcf113ffbcfe
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sears 2011-01-11 22:07:39 +00:00
parent abe7e36640
commit 975410845f
1 changed files with 11 additions and 2 deletions
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13
mergeStats.h
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@ -38,6 +38,15 @@ class mergeStats {
mergeManager::double_to_ts(&stats_last_tick, mergeManager::tv_to_double(&last));
#endif
}
pageid_t rb_size_estimator(pageid_t num_bytes, pageid_t num_tuples) {
// Experimentally determined numbers
// pageid_t small_tup_est = num_bytes + 110L * num_tuples;
// pageid_t big_tup_est = num_bytes + (2L * num_bytes) / 100L;
// Pessimistic numbers
pageid_t small_tup_est = num_bytes + 220L * num_tuples;
pageid_t big_tup_est = num_bytes + (4L * num_bytes) / 100L;
return big_tup_est > small_tup_est ? big_tup_est : small_tup_est; // max
}
public:
mergeStats(int merge_level, int64_t target_size) :
merge_level(merge_level),
@ -149,8 +158,8 @@ class mergeStats {
}
pageid_t get_current_size() {
if(merge_level == 0) {
printf("base = %lld in_s = %lld in_l = %lld out = %lld\n", base_size, bytes_in_small, bytes_in_large, bytes_out);
return base_size + bytes_in_small - bytes_in_large - bytes_out;
return rb_size_estimator(base_size + bytes_in_small - bytes_in_large - bytes_out,
/*num_tuples_base + */ num_tuples_in_small - num_tuples_in_large - num_tuples_out);;
} else {
// s->bytes_out has strange semantics. It's how many bytes our input has written into this tree.
return base_size + bytes_out - bytes_in_large;