A tool which transforms a CSV file into another CSV file using a SQL statement.
Many tools spit out CSV, or are able to as one of output options. Also, in hudson, you can very simply log any values you get into bash like echo " $val2, $val2" >> data.csv, for each build or part of a build. So it can be kind of integration tool.
Then you can do quite complex queries – from a flat table, you can actually do subselects and then left joins, which gives you very powerful tool to process the data into something what is ready for plotting as-is – that means, data filtered, cleaned, aggregated, converted, aligned, sorted, etc.
crunch input.csv output.csv "SELECT AVG(duration) AS durAvg FROM (SELECT * FROM indata ORDER BY duration LIMIT 2 OFFSET 6)"`