technotes · topic

MongoDB

First-principles depth, taught by contrast with Postgres/InnoDB — the document model, WiredTiger storage, indexing, the aggregation pipeline, replica sets & sharding.

GlossaryContext: MongoDB current (7.0/8.0+)Course in progress

Lessons

1. 0001 The document model

   The document is the unit of storage, atomicity, and schema design — so embedding, single-document atomicity, and "design for your access pattern" all derive from one keystone fact.

   done
2. 0002 WiredTiger: how documents are stored

   The storage engine up close — a B-tree, document-level concurrency, MVCC snapshots, the journal and checkpoints. The surprise: closer to InnoDB than to the Postgres heap.

   planned
3. 0003 Indexing & the ESR rule

   The mandatory _id index, compound indexes and the Equality-Sort-Range rule, multikey (array) indexes, and covered queries.

   planned

Reference