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379What Is a Document Store?
380Document Structure and Schema Flexibility
381Documents vs Rows in Relational Databases
382Document IDs and Primary Keys
383Collections and Databases
384Querying Documents by Fields
385Indexing in Document Stores
386Embedded Documents vs References
387CRUD Operations on Documents
388When Document Stores Fit Your Data Model
389MongoDB Document Model and Collections
390BSON Format and Data Types
391Primary Key and ObjectId Generation
392Indexes in MongoDB
393MongoDB Query Language Basics
394Replica Sets for High Availability
395Read and Write Concerns
396Sharding in MongoDB
397Shard Key Selection
398Config Servers and mongos Routers
399Aggregation Pipeline
400Storage Engines: WiredTiger
401Content Management Systems and Catalogs
402User Profiles and Personalization Data
403Event Logging and Analytics
404Mobile and IoT Backend Storage
405When Joins Are Required
406Complex Transaction Requirements
407Schema Flexibility Trade-offs
408Query Performance Limitations
409Data Size and Storage Considerations

379What Is a Document Store?
380Document Structure and Schema Flexibility
381Documents vs Rows in Relational Databases
382Document IDs and Primary Keys
383Collections and Databases
384Querying Documents by Fields
385Indexing in Document Stores
386Embedded Documents vs References
387CRUD Operations on Documents
388When Document Stores Fit Your Data Model
389MongoDB Document Model and Collections
390BSON Format and Data Types
391Primary Key and ObjectId Generation
392Indexes in MongoDB
393MongoDB Query Language Basics
394Replica Sets for High Availability
395Read and Write Concerns
396Sharding in MongoDB
397Shard Key Selection
398Config Servers and mongos Routers
399Aggregation Pipeline
400Storage Engines: WiredTiger
401Content Management Systems and Catalogs
402User Profiles and Personalization Data
403Event Logging and Analytics
404Mobile and IoT Backend Storage
405When Joins Are Required
406Complex Transaction Requirements
407Schema Flexibility Trade-offs
408Query Performance Limitations
409Data Size and Storage Considerations

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Lesson 391 of 1,919·11. NoSQL: Document StoresPro lesson

Primary Key and ObjectId Generation

How MongoDB automatically generates unique _id fields using ObjectIds that embed timestamp and machine information.

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