Data Access

EF Core in depth (fundamentals through perf, concurrency, migrations, and 9/10 changes), Dapper and raw SQL, connection pooling and isolation, SQL Server internals an app dev must know, and NoSQL + event-sourced stores.

The sidebar under this section is grouped into Data Fundamentals (database normalization, connection pooling, SQL Server internals — primer material), EF Core (six topics covering everything from DbContext lifetime through 9/10 changes), and Beyond EF Core (Dapper for raw SQL and the NoSQL / event-sourced stores story).

Topics (canonical order)

EF Core Fundamentals

DbContext lifetime, change tracking, DbSet, model building basics
EF Core — Querying & Projections

Include vs Select, AsNoTracking, split queries, IQueryable composition
EF Core — Performance

N+1, compiled queries, identity resolution, indexes, SaveChanges interceptors
EF Core — Migrations

Add/remove migrations, idempotent SQL scripts, deployment strategies, blue/green rules
EF Core — Concurrency & Transactions

Optimistic concurrency, row versions, TransactionScope, distributed-tx warnings
EF Core 9/10 Changes

Parameterized collections, complex types, primitive collections, vector search (EF 10)
Dapper & Raw SQL

When to drop ORM, Dapper basics, mapping, perf comparison
Connection Pooling & Isolation

ADO.NET connection pool, isolation levels, deadlock vs lock escalation
:material-microsoft-sql-server:{ .lg .middle } SQL Server Internals for App Devs

Query plans, indexing strategy, statistics, when to drop to ADO.NET
NoSQL & Event Stores

Cosmos DB SDK (partition keys, RUs), MongoDB, Marten, EventStoreDB
Database Normalization & Denormalization

Normal forms (1NF–BCNF), denormalization for read paths, materialized views, OLTP vs reporting trade-offs

Why this order

EF Core dominates real-world .NET data access, so it leads. Within EF Core: fundamentals → querying → perf → migrations → concurrency → 9/10 deltas mirrors the order an engineer hits real problems. Dapper / raw SQL / pool & isolation come next because every senior eventually drops below EF for hot paths. SQL Server internals follows so the engineer can read query plans intelligently. NoSQL + event stores closes the section as the alternative to relational.

Cross-references

EF Core perf cross-links into Performance and Observability for diagnostics.
Concurrency & transactions feed Outbox & Inbox Patterns (the outbox pattern is a transactional DB write).
Event stores link to DDD Tactical Patterns and Case: Event-Driven Order Pipeline.