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NoSQL Stores

Key-value, document, wide-column and graph — what each buys and forbids.

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Drill this topic All of Data Architecture
Questions

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  1. intermediate

    A team wants to move a workload from PostgreSQL to a document store because "the schema keeps changing". What do you ask?

    2 min answer
Terminology

3 terms in this topic

tool

Document Store

A store that keeps semi-structured documents — typically JSON — retrievable by key and queryable by their contents.

 tool

Graph Database

A store whose first-class citizens are nodes and the relationships between them, making multi-hop traversal cheap.

 tool

Wide-Column Store

A store organised as partitions of sorted rows, designed for very high write throughput and predictable single-partition reads at large scale.
Data Architecture

Neighbouring topics

Data Architecture

General material on structuring, storing and governing data.

7 quiz 25 cards 23 terms

Relational Modelling

Normalisation, keys, constraints and the invariants a schema enforces.

1 quiz 4 cards 3 terms

Indexing

Designing indexes per query shape, and paying for them on every write.

1 quiz 3 cards 3 terms

Query Optimisation

Reading a plan, fixing statistics, and finding the real bottleneck.

1 quiz 3 cards 2 terms

Transactions & Isolation

ACID, isolation levels, and the anomalies each level permits.

2 cards 2 terms

Replication

Primaries, replicas, lag, and synchronous versus asynchronous durability.

1 quiz 3 cards 3 terms

Partitioning & Sharding

Splitting data across machines, and the one-way door of a partition key.

2 cards 1 terms

Caching Strategies

Cache-aside, read-through, write-through and where each belongs.

1 cards 1 terms

Cache Invalidation

Stampedes, penetration, staleness windows and versioned keys.

1 cards 2 terms

CQRS

Separating the write model from the read models that serve queries.

1 quiz 2 cards 2 terms

Event Sourcing

Storing the change log as the system of record, and what that costs forever.

1 quiz 3 cards 3 terms

Change Data Capture

Turning a database's replication log into a stream, and its coupling risk.

1 quiz 3 cards 3 terms

Data Warehousing

Dimensional modelling, star schemas and analytical workloads.

1 quiz 3 cards 3 terms

Data Lakes & Lakehouses

Open formats on object storage with transactional metadata on top.

1 quiz 3 cards 3 terms

ETL & ELT

Where transformation happens, and how much raw history you keep.

1 quiz 3 cards 3 terms

Streaming Data

Windowing, watermarks, late arrivals and exactly-once semantics.

1 quiz 4 cards 3 terms

Data Governance

Ownership, lineage, quality, catalogues and who may see what.

1 quiz 3 cards 3 terms

Data Lifecycle & Retention

How long data is kept, where it ages to, and how it is actually deleted.

1 quiz 3 cards 3 terms

Polyglot Persistence

Choosing a store per workload, and the operational cost of variety.

2 quiz 2 cards 2 terms