Uploaded image for project: 'Documentation'
  1. Documentation
  2. DOCS-10547

Docs for SERVER-142: Read-only views over collection data.

    XMLWordPrintableJSON

Details

    • Icon: Task Task
    • Resolution: Duplicate
    • Icon: Major - P3 Major - P3
    • 3.3.12
    • None
    • None
    • None

    Description

      Documentation Request Summary:

      No documentation summary in engineering ticket

      Engineering Ticket Description:

      Issue Status as of Aug 31, 2016

      ISSUE SUMMARY
      MongoDB 3.3.12 adds support for creating read-only views over existing collections or other views. To specify or define a view, MongoDB introduces the viewOn and pipeline options to the existing create command:

      db.runCommand( { create: <view>, viewOn: <source>, pipeline: <pipeline> } )
      

      In addition, there's also a mongo shell helper db.createView():

      db.createView(<view>, <source>, <pipeline>)

      Views are readable via the following commands:

      For more information views, as well as examples, please see the Read-only Views documentation.

      Original description

      Support for read-only views will consist of providing a mechanism for binding a namespace name to a (namespace name, query) pair, where the query might be a MongoDB query or an aggregation expression. For example, if you had a collection "housing.apartments", you might create a view

      housing.cheapApartments = (housing.apartments, { rent: { $lte: 1000 } })
      

      Finds on cheapApartments would only consider those elements of housing.apartments where the "rent" field was less than 1000.

      By using an aggregation expression with an unwind stage, you could produce a view over a database that had one document for every member of an array in an input document, providing another means to examine and query embedded documents.

      Attachments

        Activity

          People

            Unassigned Unassigned
            emily.hall Emily Hall
            Votes:
            0 Vote for this issue
            Watchers:
            1 Start watching this issue

            Dates

              Created:
              Updated:
              Resolved:
              6 years, 30 weeks, 1 day ago