Free Practice Questions for MongoDB C100DBA Exam

MongoDB stores records as BSON documents. BSON, short for Binary JSON, is a binary serialization format that preserves the JSON-like document model while supporting a richer set of data types required by database applications. Mongosh commonly displays documents using JavaScript or Extended JSON-like notation, which is why JSON is a tempting distractor, but the native stored representation is BSON. BSON supports types such as ObjectId, dates, binary data, timestamps, Decimal128, 32-bit and 64-bit integers, arrays, embedded documents, and other values that standard JSON does not represent natively. Base64 is an encoding technique often used to render binary data as text and is not MongoDB ' s document storage format. XML is also unrelated to MongoDB ' s native representation. Understanding BSON is fundamental for database administrators because document-size limits, type comparisons, index keys, serialization behavior, and driver interoperability all depend on BSON semantics. The flexible document model allows fields to contain scalar values, nested documents, and arrays within the same record structure. Therefore the encoded format used by MongoDB to store documents is BSON, making option C correct.

Study Guide reference/topic:MongoDB Architecture and Core Operations - BSON, document structure, data types, and JSON/BSON distinctions.

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MongoDB Enterprise auditing supports three standard destination values for audit events: syslog, file, and console. With the syslog destination, audit records are sent to the operating system ' s syslog facility where supported. With the file destination, events are written to a configured audit log path, and administrators can control the output format according to the supported audit configuration. With the console destination, audit events are emitted to standard output, which can be useful in containerized or centrally collected logging environments. A raw TCP/IP port is not itself an auditLog.destination value. Organizations can certainly forward logs over the network using operating-system or observability tooling, but that transport is external to MongoDB ' s destination setting. A MongoDB database is likewise not one of the supported audit destinations; keeping audit evidence independent from the system being audited is also preferable for integrity and compliance. Auditing records security-relevant actions and can be filtered to meet regulatory or operational requirements. Therefore the three valid destinations among the choices are syslog, file, and console: A, B, and E.

Study Guide reference/topic:Security, Networking, and Encryption - auditing, auditLog.destination, compliance logging, and audit configuration.

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mongosh accepts a MongoDB host address in hostname:port form, so mongosh " node-1.cluster1.mycompany.local:27017 " is the valid choice among the commands shown. A canonical URI form such as mongosh " mongodb://node-1.cluster1.mycompany.local:27017 " is also valid, and the connection can alternatively be expressed using --host together with --port. Option A uses an unsupported --hostname switch rather than the documented --host option. Option B invents a --connect flag that is not the standard mongosh interface. Option C constructs an invalid string using an ampersand-style parameter rather than a MongoDB URI or a normal host:port target. Port 27017 is MongoDB ' s default server port, so it could often be omitted if the deployment uses the default, but explicitly including it is valid and removes ambiguity. In authenticated or TLS-enabled environments, the DBA would also supply credentials, authentication database, certificate settings, or a connection string carrying those parameters. For the simple host-and-port requirement in the question, option D is correct.

Study Guide reference/topic:Security, Networking, and Encryption - mongosh connectivity, host/port addressing, and connection options.

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