MongoDB’s data model¶

MongoDB stores data in collections and documents. CrateDB stores data in tables and rows.

A database in MongoDB is a physical container for collections, roughly corresponding to a schema in CrateDB, which groups tables together.
A collection in MongoDB is a grouping of documents, similar to a table in CrateDB, which is a structured collection of rows.
A document in MongoDB is a record in a collection, similar to a row in a CrateDB table. It is a set of key-value pairs. Note: Nested structures can be modeled in CrateDB using OBJECT columns when appropriate.
A field in MongoDB is similar to a column in a CrateDB table. In both systems, fields (or columns) define the attributes for the records (or rows/documents).
A primary key in MongoDB is typically the _id field, which uniquely identifies a document within a collection. In CrateDB, a primary key uniquely identifies a row in a table.
An index in MongoDB is similar to an index in CrateDB. Both are used to improve query performance by providing a fast lookup for fields (or columns) within documents (or rows).