R to Solr Interface

A comprehensive R API for querying Apache Solr databases. A Solr core is represented as a data frame or list that supports Solr-side filtering, sorting, transformation and aggregation, all through the familiar base R API. Queries are processed lazily, i.e., a query is only sent to the database when the data are required.


The `rsolr` package is an idiomatic R interface to Solr based on deferred evaluation. A Solr core is represented as a data frame or list that supports Solr-side filtering, sorting, transformation and aggregation, all through the familiar base R API. Queries are processed lazily, i.e., a query is only sent to the database when the data are required.

Features

  • Store, retrieve and compute on data with Solr, from R
  • Use familiar R syntax and function names from the base R API, with some extensions
  • Model data as either a data.frame or list, or use the low-level query API
  • Conveniently manipulate document collections after retrieval
  • Autogenerate a Solr schema from a data.frame
  • Experiment with the embedded Solr instance
  • Extend to support additional/custom Solr features

Example using data from R

This is inspired by some manipulations in the dplyr vignette.

Load the New York City 2013 flight data and upload to Solr:

library(nycflights13)
schema <- deriveSolrSchema(flights)
solr <- rsolr:::TestSolr(schema)
sr <- SolrFrame(solr$uri)
sr[] <- flights

Filtering:

subset(sr, month == 1 & day == 1)
head(sr, 10L)

Sorting:

sort(sr, by = ~ year + month + day)

Select fields:

subset(sr, select=c(year, month, day))
sr[c("year", "month", "day")]
sr[c("arr_*", "dep_*")] # Solr globs

Transform:

sr2 <- transform(sr,
                 gain = arr_delay - dep_delay,
                 speed = distance / air_time * 60)
sr2[c("gain", "speed")]

Aggregate:

unique(sr["tailnum"])
aggregate(~ tailnum, sr,
          count = TRUE,
          dist = mean(distance, na.rm=TRUE),
          delay = mean(arr_delay, na.rm=TRUE))

Example using existing Solr core

Construct a SolrFrame using the URL to the existing core:

sr <- SolrFrame("http://my.host.com/solr/mycore")

Convert the SolrFrame to a data.frame, typically after some filtering or aggregation:

df <- as.data.frame(sr)

News

Reference manual

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install.packages("rsolr")

0.0.9 by Michael Lawrence, 10 months ago


Browse source code at https://github.com/cran/rsolr


Authors: Michael Lawrence , Gabe Becker , Jan Vogel


Documentation:   PDF Manual  


Apache License (== 2.0) license


Imports restfulr, graph, S4Vectors, rjson, XML, RCurl

Depends on BiocGenerics, methods

Suggests nycflights13, RUnit, MASS


Imported by trackr.

Suggested by restfulr.


See at CRAN