Thursday, March 13, 2014

HANA Query Performance

I loaded 2013 weather observation today, so I finally have enough data to do report basic query performance.

This query returns maximum temperature readings for a particular weather station. It joins the weather observation table (33 million rows) with the station table (91,000 rows).  There are no keys or indexes.

select * from "WEATHER_DATA"."Critigen.WeatherData.Data::DAILY_WEATHER_OBS" d
inner join "WEATHER_DATA"."Critigen.WeatherData.Data::STATION" s on d.STATION_ID = s.ID
where s.STATE = 'CO' and d.ELEMENT = 'TMAX' and d.STATION_ID = 'USC00053147'
order by d.YYYYMMDD

The query returned 396 rows in 335 ms. The overall scan rate was 99 million rows per second.

No comments: