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AlloyDB for PostgreSQL vs Google Cloud Spanner

AlloyDB for PostgreSQL: Google's Postgres-compatible service with disaggregated storage, a columnar engine and ScaNN vectors. Google Cloud Spanner: Google's globally consistent, horizontally scaling SQL service with graph, vector and full-text built in.

key differences

  • Google Cloud Spanner is built for larger datasets (Multi-PB) than AlloyDB for PostgreSQL (≤ 1 PB).
  • Horizontal scaling is none in AlloyDB for PostgreSQL and native in Google Cloud Spanner.
  • Only AlloyDB for PostgreSQL has geospatial, triggers, stored procedures, materialized views, pub/sub.
  • Only Google Cloud Spanner has ttl / expiry, time travel, online schema changes.

choose alloydb for

  • +Migrating demanding Postgres or Oracle workloads to Google Cloud
  • +Operational analytics on live transactional data
  • +RAG and semantic search with vectors stored beside business data
  • +Hybrid deployments using AlloyDB Omni on-premises

best at · OLTP, HTAP, Vector search

choose google-cloud-spanner for

  • +Global financial ledgers and payment systems
  • +Gaming backends with worldwide player state
  • +Inventory and supply-chain systems of record
  • +Identity and metadata services at very high write rates

best at · OLTP, Traversal, Vector search

AlloyDB for PostgreSQLGoogle's Postgres-compatible service with disaggregated storage, a columnar engine and ScaNN vectors.
Google Cloud SpannerGoogle's globally consistent, horizontally scaling SQL service with graph, vector and full-text built in.
overview
Primary model
Relational
Relational
Also supports
Document, Spatial, Vector, Columnar / OLAP
Graph, Key-Value, Vector, Search Engine
Type
Managed service
Managed service
Status
Active
Active
Developer
Google
Google
First release
2022
2017
Latest version
–
–
License
ProprietaryProprietary (Google Cloud service; AlloyDB Omni commercial license)
ProprietaryProprietary (Google Cloud service)
Free tier
—
—
popularity
WhichDB Score
3.6
34.5
Rank
#430
#59
GitHub stars
–
–
Stack Overflow questions
40
733
scale & guarantees
Comfortable data size
Large (≤ 1 PB)
Massive (Multi-PB)
Horizontal scaling
None
Native
Multi-region
Read replicas
Active active
ACID
Full
Full
Consistency
Strong
Strong
Schema
Strict
Strict
Architecture
Shared storage, Primary replica
Distributed, Multi primary
deployment
Self-hosted
✓
—
Vendor-managed cloud
✓
✓
Serverless
—
—
Embedded
—
—
Edge
—
—
Clouds
Google Cloud
Google Cloud
capabilities
Transactions
✓
✓
Joins
✓
✓
Secondary indexes
✓
✓
Full-text search
✓
✓
Vector search
✓
✓
Geospatial
✓
—
JSON
✓
✓
Change data capture
✓
✓
Triggers
✓
—
Stored procedures
✓
—
Materialized views
✓
—
TTL / expiry
—
✓
Pub/Sub
✓
—
Columnar storage
✓
—
In-memory
✓
—
Durable persistence
✓
✓
Compression
✓
✓
Encryption at rest
✓
✓
Role-based access
✓
✓
Time travel
—
✓
Branching
—
—
Online schema changes
—
✓
Streaming ingest
—
—
Offline sync
—
—
Runs in WebAssembly
—
—
interfaces
Query languages
SQL, PL/pgSQL
GoogleSQL, PostgreSQL dialect, GQL
Client languages
Java, Python, Go, JavaScript, C#, Ruby, PHP
Java, Go, Python, JavaScript, C#, C++, PHP, Ruby
Best for
OLTP, HTAP, Vector search, RAG
OLTP, Traversal, Vector search, Search
Add more to this comparisonNot sure either fits? Try smart match

AlloyDB for PostgreSQL vs Google Cloud Spanner: FAQ

What is the difference between AlloyDB for PostgreSQL and Google Cloud Spanner?

AlloyDB for PostgreSQL: Google's Postgres-compatible service with disaggregated storage, a columnar engine and ScaNN vectors. Google Cloud Spanner: Google's globally consistent, horizontally scaling SQL service with graph, vector and full-text built in. Google Cloud Spanner is built for larger datasets (Multi-PB) than AlloyDB for PostgreSQL (≤ 1 PB). Horizontal scaling is none in AlloyDB for PostgreSQL and native in Google Cloud Spanner. Only AlloyDB for PostgreSQL has geospatial, triggers, stored procedures, materialized views, pub/sub.

When should I choose AlloyDB for PostgreSQL over Google Cloud Spanner?

Choose AlloyDB for PostgreSQL for migrating demanding Postgres or Oracle workloads to Google Cloud; operational analytics on live transactional data; and RAG and semantic search with vectors stored beside business data. Choose Google Cloud Spanner for global financial ledgers and payment systems; gaming backends with worldwide player state; and inventory and supply-chain systems of record.

Is AlloyDB for PostgreSQL or Google Cloud Spanner more popular?

Google Cloud Spanner ranks #59 on the WhichDB Score (34.5/100) and AlloyDB for PostgreSQL ranks #430 (3.6/100). Popularity is not fit: check the requirements that matter for your project.

Are AlloyDB for PostgreSQL and Google Cloud Spanner open source?

No. AlloyDB for PostgreSQL is proprietary, closed-source software. No. Google Cloud Spanner is proprietary, closed-source software.