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URL: http://<db.host>:<db.port>/aggregate/statistics
Calculates the requested statistics of the given column(s) in a given table. The available statistics are: count (number of total objects), mean, stdv (standard deviation), variance, skew, kurtosis, sum, min, max, weighted_average, cardinality (unique count), estimated_cardinality, percentile, and percentile_rank. Estimated cardinality is calculated by using the hyperloglog approximation technique. Percentiles and percentile ranks are approximate and are calculated using the t-digest algorithm. They must include the desired percentile/percentile_rank. To compute multiple percentiles each value must be specified separately (i.e. ‘percentile(75.0),percentile(99.0),percentile_rank(1234.56),percentile_rank(-5)’). A second, comma-separated value can be added to the percentile statistic to calculate percentile resolution, e.g., a 50th percentile with 200 resolution would be ‘percentile(50,200)’. The weighted average statistic requires a weight column to be specified in weight_column_name. The weighted average is then defined as the sum of the products of input parameter column_name times the weight_column_name values divided by the sum of the weight_column_name values. Additional columns can be used in the calculation of statistics via additional_column_names. Values in these columns will be included in the overall aggregate calculation—individual aggregates will not be calculated per additional column. For instance, requesting the count and mean of input parameter column_name x and additional_column_names y and z, where x holds the numbers 1-10, y holds 11-20, and z holds 21-30, would return the total number of x, y, and z values (30), and the single average value across all x, y, and z values (15.5). The response includes a list of key/value pairs of each statistic requested and its corresponding value.

Input Parameter Description

table_name
string
Name of the table on which the statistics operation will be performed, in [schema_name.]table_name format, using standard name resolution rules.
column_name
string
Name of the primary column for which the statistics are to be calculated.
stats
string
Comma separated list of the statistics to calculate, e.g. “sum,mean”.
  • count: Number of objects (independent of the given column(s)).
  • mean: Arithmetic mean (average), equivalent to sum/count.
  • stdv: Sample standard deviation (denominator is count-1).
  • variance: Unbiased sample variance (denominator is count-1).
  • skew: Skewness (third standardized moment).
  • kurtosis: Kurtosis (fourth standardized moment).
  • sum: Sum of all values in the column(s).
  • min: Minimum value of the column(s).
  • max: Maximum value of the column(s).
  • weighted_average: Weighted arithmetic mean (using the option weight_column_name as the weighting column).
  • cardinality: Number of unique values in the column(s).
  • estimated_cardinality: Estimate (via hyperloglog technique) of the number of unique values in the column(s).
  • percentile: Estimate (via t-digest) of the given percentile of the column(s) (percentile(50.0) will be an approximation of the median). Add a second, comma-separated value to calculate percentile resolution, e.g., ‘percentile(75,150)’.
  • percentile_rank: Estimate (via t-digest) of the percentile rank of the given value in the column(s) (if the given value is the median of the column(s), percentile_rank(<median>) will return approximately 50.0).
options
map of string to strings
Optional parameters.The default value is an empty map ( {} ).

Output Parameter Description

The Kinetica server embeds the endpoint response inside a standard response structure which contains status information and the actual response to the query. Here is a description of the various fields of the wrapper:
status
String
‘OK’ or ‘ERROR’
message
String
Empty if success or an error message
data_type
String
‘aggregate_statistics_response’ or ‘none’ in case of an error
data
String
Empty string
data_str
JSON or String
This embedded JSON represents the result of the /aggregate/statistics endpoint:Empty string in case of an error.