The Stats component returns simple statistics for numeric, string, and date fields within the document set. This is useful for many taskes. It’s particulary useful for summarizing how much disk space is used by a query result
For instance the following query returns the all of the Tiff items in the index
https://odn.voyagersearch.com/solr/v0/select?fq=format%3Aimage\%2Ftiff&fl=*&wt=json&indent=true
Adding “stats” to the query will return statistics at the end of the results:
&stats=true&stats.field=bytes
The complete query is as follows
https://odn.voyagersearch.com/solr/v0/select?fq=format%3Aimage\\%2Ftiff&fl=*&wt=json&indent=true&stats=true&stats.field=bytes
The results can be found after the “doc” section of the response:
stats: { stats_fields: { bytes: { min: 0, max: 21340766014, count: 12419673, missing: 344732, sum: 500288101188175, sumOfSquares: 1.0591308004924849e+23, mean: 40281906.06855551, stddev: 83097631.23762643 } } }
In this example the total number of Terabytes is:
500,288,101,188,175 Bytes ÷ 1,099,511,627,776 = 500.3 Terabytes