Ordered Guide to Big Data, Data Lakes, Data Warehouses & Lakehouses
1 The Modern Data Landscape — Bird’s‑Eye View
Data Sources → Ingestion → Storage → Processing → Analytics / ML → Decisions
Every storage paradigm slots into this flow at the Storage layer, but each optimises different trade‑offs for the rest of the pipeline.
2 Foundations: What Is Big Data?
5 Vs | Meaning |
---|---|
Volume | Petabytes+ generated continuously |
Velocity | Milliseconds‑level arrival & processing |
Variety | Structured, semi‑structured, unstructured |
Veracity | Data quality & trustworthiness |
Value | Business insights unlocked by analytics |
Typical Sources: social media streams, IoT sensors, click‑streams, transactions, logs, images, videos.
3 Storage Paradigms in Order
3.1 Traditional Databases
- Relational (RDBMS) — schema‑on‑write, ACID (MySQL, PostgreSQL, Oracle)
- NoSQL families — key‑value, document, column‑family, graph (Redis, MongoDB, Cassandra, Neo4j)
Pros: strong consistency (RDBMS) or horizontal scale (NoSQL)
Cons: limited for petabyte‑scale raw data or multi‑format analytics
3.2 Data Lake
Object storage that accepts raw data as‑is (schema‑on‑read).
Layers
- Storage: S3, ADLS, GCS
- Ingestion: Kafka, Flink, AWS Glue
- Catalog: AWS Glue Data Catalog, Unity Catalog
- Processing: Spark, Presto, Athena
- Governance: IAM, encryption, audit logs
Strengths: low‑cost, flexible, ML‑friendly
Challenges: governance, slow ad‑hoc SQL without optimisation
3.3 Big Data Lake (Enterprise‑Grade)
An evolved lake built for multi‑cloud scale, strict governance, and real‑time workloads.
- Adds ACID & versioning with Delta Lake, Apache Hudi, Iceberg
- Data lineage, column‑level access control, and time‑travel queries
3.4 Data Warehouse
Schema‑on‑write repository optimised for OLAP analytics.
Architecture
Sources → ETL → Staging → Warehouse (Star / Snowflake) → BI & Marts
- Cloud DWs: Snowflake, BigQuery, Amazon Redshift, Azure Synapse
- On‑prem DWs: Teradata, Oracle Exadata
Pros: blazing‑fast SQL, consistent “single source of truth”
Cons: higher storage cost, rigid schema, mostly structured data
3.5 Data Lakehouse
Unifies lake flexibility with warehouse performance via open table formats.
- Delta Lake / Iceberg / Hudi underpin ACID, indexing, time‑travel
- Enables BI & ML on the same copy of data
4 Quick Comparison
Aspect | Data Lake | Data Warehouse | Lakehouse |
---|---|---|---|
Schema | On‑read | On‑write | Both |
Data Types | All formats | Structured | All formats |
Query Speed | Medium (needs optimisation) | High | High |
Cost | Low (object storage) | Higher | Low‑medium |
Governance | Add‑on tools | Built‑in | Built‑in |
Best For | Exploratory analytics & ML | BI, dashboards | Unified workloads |
5 Architectural Lineage Diagrams
5.1 Data Lake Lineage
┌────────┐ ┌───────────────┐ ┌──────────┐ ┌────────────┐
| Source │→│ Raw Object Stg │→│ Catalog │→│ Spark / Presto │→ BI / ML
└────────┘ └───────────────┘ └──────────┘ └────────────┘
5.2 Data Warehouse Lineage
┌────────┐ ┌───────┐ ┌──────────┐ ┌──────────┐ ┌──────┐
| Source │→│ ETL │→│ Staging │→│ Fact & Dim │→ BI │
└────────┘ └───────┘ └──────────┘ └──────────┘ └──────┘
5.3 Lakehouse Lineage
┌────────┐ ┌───────────────┐ ┌────────────────┐ ┌──────────┐
| Source │→│ Bronze (T1) │→│ Silver (optimised) │→│ Gold (BI) │
└────────┘ └───────────────┘ └────────────────┘ └──────────┘
6 Technology Cheat‑Sheet
Layer | Lake / Lakehouse | Warehouse |
---|---|---|
Storage | S3, ADLS, GCS | Columnar (Parquet, ORC), block |
Metadata | Glue, Hive Metastore, Unity Catalog | Internal catalogs |
Compute | Spark, Databricks, Flink, Presto | MPP engines (Snowflake, BigQuery) |
Governance | Lake Formation, Ranger | RBAC, column‑level sec |
Orchestration | Airflow, DBT, MWAA | Airflow, DBT |
7 Choosing the Right Approach
- Need historical KPIs, CFO‑grade accuracy? → Warehouse
- Exploratory data science on raw logs & images? → Data Lake
- Desire one platform for BI + ML without duplication? → Lakehouse
- Regulated enterprise, petabytes, multi‑cloud? → Big Data Lake + Lakehouse overlay
8 Challenges & Best Practices
- Governance — implement catalog + column‑level ACLs early.
- Cost Control — tiered storage & auto‑vacuum unused data.
- Performance — partition, Z‑order, and cache hot data.
- Data Quality — enforce contracts (Great Expectations, Deequ).
9 Key Takeaways
Big Data (the raw ingredients) needs the right pantry:
- Lakes deliver flexibility; warehouses deliver speed; lakehouses strive for both.
- The storage choice dictates downstream tooling, governance, and cost—but they are complementary pieces of a single analytics continuum.
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