field_stats: Search field statistics

Description

Search field statistics

Usage

field_stats(
  conn,
  fields = NULL,
  index = NULL,
  level = "cluster",
  body = list(),
  raw = FALSE,
  asdf = FALSE,
  ...
)

Arguments

conn

an Elasticsearch connection object, see connect()

fields

A list of fields to compute stats for. optional

index

Index name, one or more

level

Defines if field stats should be returned on a per index level or on a cluster wide level. Valid values are 'indices' and 'cluster' (default)

body

Query, either a list or json

raw

(logical) Get raw JSON back or not

asdf

(logical) If TRUE, use fromJSON to parse JSON directly to a data.frame. If FALSE (Default), list output is given.

...

Curl args passed on to crul::HttpClient

Details

The field stats api allows you to get statistical properties of a field without executing a search, but looking up measurements that are natively available in the Lucene index. This can be useful to explore a dataset which you don't know much about. For example, this allows creating a histogram aggregation with meaningful intervals based on the min/max range of values.

The field stats api by defaults executes on all indices, but can execute on specific indices too.

References

https://www.elastic.co/guide/en/elasticsearch/reference/5.6/search-field-stats.html

Examples

Run this code

# NOT RUN {
x <- connect()

if (gsub("\\.", "", x$ping()$version$number) < 500) {
  field_stats(x, body = '{ "fields": ["speaker"] }', index = "shakespeare")
  ff <- c("scientificName", "continent", "decimalLatitude", "play_name", 
    "speech_number")
  field_stats(x, "play_name")
  field_stats(x, "play_name", level = "cluster")
  field_stats(x, ff, level = "indices")
  field_stats(x, ff)
  field_stats(x, ff, index = c("gbif", "shakespeare"))

  # can also pass a body, just as with Search()
  # field_stats(x, body = list(fields = "rating")) # doesn't work
  field_stats(x, body = '{ "fields": ["scientificName"] }', index = "gbif")

  body <- '{
    "fields" : ["scientificName", "decimalLatitude"]
  }'
  field_stats(x, body = body, level = "indices", index = "gbif")
}
# }