Inkdown
Start writing

Study

70 files·12 subfolders

Shared Workspace

Study
AI eng

02-relational-databases

Shared from "Study" on Inkdown

02 - Relational Databases & SQL

What is a Relational Database?

A relational database organizes data into tables (relations) with predefined schemas. Tables relate to each other through keys, enabling powerful queries across multiple tables.

The Relational Model
Plain text
basic-ques
core
Revision w/ Whiteboard
CN Basics - 1
CN Basics - 2
DNS
Event loop
programming-language-concepts.md
zero-language-explanation.md
DB
Quick
databases-deep-dive.md
01-introduction.md
02-relational-databases.md
03-database-design.md
04-indexing.md
05-transactions-acid.md
06-nosql-databases.md
07-query-optimization.md
08-replication-ha.md
09-sharding-partitioning.md
10-caching-strategies.md
11-cap-theorem.md
12-connection-pooling.md
13-backup-recovery.md
14-monitoring.md
15-database-selection.md
README.md
JS
core topics
Event loop
Merlin Backend
01-Orchestration.md
02-DeepResearch.md
03-Search.md
04-Scraping.md
05-Streaming.md
06-MultiProviderLLM.md
07-MemoryAndContext.md
08-ErrorHandling.md
09-RateLimiting.md
10-TaskQueue.md
11-SecurityAndAuth.md
Orchestration-2nd-draft
Mobile
Build Alternative
Bundling
metro-bundler-deep-dive.md
OpenAI Agents Python
00_OVERVIEW.md
01_AGENT_SYSTEM.md
02_RUNNER_SYSTEM.md
03_TOOL_SYSTEM.md
04_ITEMS_SYSTEM.md
05_GUARDRAILS.md
06_HANDOFFS.md
07_MEMORY_SESSIONS.md
08_MODEL_PROVIDERS.md
09_SANDBOX_SYSTEM.md
10_TRACING.md
11_RUN_STATE.md
12_CONTEXT.md
13_LIFECYCLE_HOOKS.md
14_CONFIGURATION.md
15_ERROR_HANDLING.md
16_STREAMING.md
17_EXTENSIONS.md
18_MCP_INTEGRATION.md
19_BEST_PRACTICES.md
20_ARCHITECTURE_PATTERNS.md
opencode-study
context-handling
core
Python
Alembic
Basics
sqlalchemy - fastapi
SQLAlchemy overview
tweets
system_design_for_agentic_apps.md
Agent Loop

SQL: Structured Query Language

SQL is the standard language for relational databases. It has several sub-languages:

1. DDL (Data Definition Language) - Structure
Sql
2. DML (Data Manipulation Language) - Data
Sql
3. DQL (Data Query Language) - Retrieval
Sql
4. JOINs: Combining Tables
Sql
5. Subqueries & CTEs
Sql
6. Window Functions (Advanced)
Sql

Data Types Deep Dive

PostgreSQL Types
Sql

Constraints & Data Integrity

Sql

Views & Materialized Views

Sql

Stored Procedures & Functions

Sql

Advanced SQL Patterns

1. UPSERT (Insert or Update)
Sql
2. Conditional Aggregation
Sql
3. Recursive CTEs (Hierarchical Data)
Sql

Best Practices

1. Query Writing
Sql
2. Schema Design
Sql
3. Security
Sql

Common Pitfalls

  1. N+1 Query Problem: Loading related data in a loop
  2. Missing Indexes: Full table scans on large tables
  3. No Pagination: Loading millions of rows at once
  4. String Concatenation in Queries: SQL Injection risk
  5. Not Using Transactions: Data inconsistency on failures
  6. Long-running Transactions: Lock contention
  7. Over-normalization: Too many joins hurt performance

Next: Database Design & Normalization