ANALYZE and ANALYZE FORMAT=JSON structures are changed in the way that they
show additional information when rowid filter is used:
- r_selectivity_pct - the observed filter selectivity
- r_buffer_size - the size of the rowid filter container buffer
- r_filling_time_ms - how long it took to fill rowid filter container
New class Rowid_filter_tracker was added. This class is needed to collect data
about how rowid filter is executed.
A 64bit counter can overflow within the time of a query
so lets take it that the measurement is the small value
rather than an order 1e12 millisecond query.
tested with:
int main()
{
ulonglong start = ULONGLONG_MAX - 30;
ulonglong end = 600;
ulonglong cycles = 10000;
cycles += end - start;
if (unlikely(end < start))
cycles += ULONGLONG_MAX;
printf("cycles %llu\n", cycles);
}
- Remove ANALYZE's timing code off the the execution path of regular
SELECTs.
- Improve the tracker that tracks counts/execution times of SELECTs or
DML statements:
= regular execution just increments counters
= ANALYZE will also collect timings.
