Question 1

Is CockroachDB really a drop-in PostgreSQL replacement?

Accepted Answer

Wire-protocol level, yes — CockroachDB speaks the Postgres protocol so most clients work unchanged. SQL-level, mostly — DML is highly compatible, but DDL has gaps (no inheritance, limited triggers, no stored procedures pre-23.x, different EXPLAIN). The bigger surprise is performance: serializable isolation by default makes some Postgres-tuned queries slower on CockroachDB; you have to think about contention patterns differently. We always recommend running your test suite against CockroachDB before assuming "drop-in."

Question 2

When does CockroachDB's horizontal scale actually win?

Accepted Answer

When you need: (a) multi-region active-active writes with serializable consistency, (b) zero-downtime upgrades and online schema changes at scale, (c) workloads that genuinely exceed single-primary Postgres throughput (rare — modern hardware handles much more than people think), (d) survivability requirements where losing a region or rack can't affect availability. For 90% of workloads, single-primary Postgres with read replicas and PgBouncer is simpler and cheaper. CockroachDB pays off in the remaining 10% where distributed semantics are an actual requirement, not a nice-to-have.

Question 3

What's the operational overhead of CockroachDB vs Postgres?

Accepted Answer

Postgres has 25+ years of operational tooling — pg_dump, pgBackRest, Patroni, repmgr, pgBadger, pg_stat_statements. CockroachDB ships a single binary with built-in HA, backup/restore, and observability via the Admin UI — but the ecosystem of third-party tools is much smaller. Postgres wins on operational maturity, CockroachDB wins on "HA is a checkbox, not a project." The choice depends on team familiarity and whether you value the larger ecosystem or the simpler ops surface.

Question 4

How does CockroachDB Cloud compare to Aurora Postgres?

Accepted Answer

CockroachDB Cloud is multi-cloud (AWS, Azure, GCP) and offers Serverless and Dedicated tiers. Aurora Postgres is AWS-only but has the deepest AWS integration. For multi-cloud distribution, CockroachDB Cloud is the obvious answer. For AWS-only at scale where you don't need cross-region writes, Aurora Postgres is cheaper, more familiar, and handles 99% of workloads with read replicas. We model both against your actual usage and surface the break-even point.

Question 5

What about YugabyteDB — same category, different choice?

Accepted Answer

Both are distributed-SQL, Postgres-protocol-compatible. CockroachDB is built around the Spanner-style architecture (Raft for replication, key-range based sharding). YugabyteDB has two storage engines: YSQL (Postgres-compatible, similar to CockroachDB) and YCQL (Cassandra-compatible). For pure Postgres-replacement intent, both are credible. CockroachDB has better serializable-isolation story; YugabyteDB has the optional Cassandra interface and Apache 2.0 license vs CockroachDB's BSL/CCL. We help model the choice when both are on the table.

Question 6

When do you migrate Postgres → CockroachDB, and when do you stay?

Accepted Answer

Stay on Postgres if: you have <500 GB working-set, you can tolerate single-region writes, your team is Postgres-fluent, you use Postgres-specific features (pgvector, PostGIS, advanced procedural code). Migrate if: regulatory requirements force multi-region active-active, you've hit genuine single-primary throughput limits (after exhausting vertical scale + read replica patterns), or you specifically value the operational simplicity of CockroachDB's HA-by-default model. We see far more "stay on Postgres + optimise" outcomes than migrations — and the migration is non-trivial when it makes sense.

Dimension	PostgreSQL 16+	CockroachDB 23+
Architecture	Single-primary with read replicas; logical replication across nodes	Distributed SQL — Raft per key range, automatic sharding
Wire protocol	Postgres protocol (native)	Postgres protocol (highly compatible, some DDL gaps)
Default isolation	Read Committed (Serializable available per-transaction)	Serializable (always — no Read Committed option)
Horizontal scale	Read replicas + Citus or partitioning for write scale	Native — add nodes, ranges auto-rebalance
Multi-region	Logical replication, read replicas across regions	Multi-region tables — active-active writes with locality control
Online schema change	Limited — ALTER TABLE locks for some operations (mitigated by pg_repack)	Native online schema changes for most DDL
Extensions	200+ — pgvector, PostGIS, TimescaleDB, pg_partman, hypopg, etc.	Limited — no extension model; built-ins only
Procedural code	PL/pgSQL, PL/Python, PL/Perl, custom languages	Stored procedures (23.x+), no PL/pgSQL extension
JSON / vector	JSONB + pgvector (HNSW, IVFFlat)	JSON type; vector support via separate index
Backups	pg_dump, pg_basebackup, pgBackRest, WAL-G	Native incremental backup; cluster-aware restore
License	PostgreSQL Licence (permissive, OSI-approved)	BSL → CCL (source-available; commercial use needs licence)
Cloud-managed	RDS, Aurora, Cloud SQL, Azure DB, Crunchy, Neon, Supabase	CockroachDB Cloud (Serverless + Dedicated) — multi-cloud

PostgreSQL vs CockroachDB

Feature matrix

When PostgreSQL wins

When CockroachDB wins

Migration paths between PostgreSQL and CockroachDB

PostgreSQL → CockroachDB

CockroachDB → PostgreSQL

Postgres + Citus (alternative)

Common questions

Need a written Postgres-vs-CockroachDB decision?