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Databases · head to head

DuckDB vs Vault

DuckDB logo

DuckDB

Databases

MIT-licensed analytical SQL database that runs inside your process, with no server, no dependencies and one writer at a time.

From
Free
Rated
-
Full reviewWebsite
Vault logo

Vault

Cloud

Manage Secrets and Protect Sensitive Data

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: DuckDB a database file accepts one read-write process at a time; other processes must open it read-only and will not see subsequent writes, so DuckDB cannot be the shared database behind several services.; Vault vault 1.15.0 and later is licensed under the Business Source License 1.1, not an OSI open source licence, with IBM Corporation as licensor
  • They diverge on capability: DuckDB covers In-process execution, Vault covers Secrets management.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which DuckDB and Vault actually diverge.

Attributes where DuckDB and Vault differ
AttributeDuckDBVault
PlatformsLinux, macOS, Windows, WebAssemblyLinux, Windows, Mac, Cloud
CategoryDatabasesCloud
Founded20192015

Identical on both: starting price (Free), pricing model (open-source), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in DuckDB

  • In-process execution
  • Vectorised columnar engine
  • Direct file querying
  • Zero dependencies
  • Larger-than-memory queries
  • MIT licence
  • Postgres-flavoured SQL
  • Extension ecosystem

Only in Vault

  • Secrets management
  • Encryption
  • Authentication
  • Authorization
  • Audit logging
  • API access
  • High availability
  • Replication

What people use each for

The jobs each tool is most often brought in to do.

DuckDB

  • Transformation steps in a data pipeline that would otherwise need Spark, replaced by SQL over Parquet in a single processnot Vault
  • Analytical queries embedded in an application or a dashboard where shipping a database server alongside it is not acceptablenot Vault
  • Local exploration of files that are too large for a pandas dataframe but far too small to justify a warehousenot Vault
  • Continuous integration and testing of analytical SQL, where a real engine can run in the test process without provisioning anythingnot Vault

Vault

  • Centrally storing and rotating secrets, API keys and database credentialsnot DuckDB
  • Issuing short-lived dynamic credentials to applications instead of static passwordsnot DuckDB
  • Encryption as a service and PKI certificate issuancenot DuckDB

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

DuckDB

  • A database file accepts one read-write process at a time; other processes must open it read-only and will not see subsequent writes, so DuckDB cannot be the shared database behind several services.
  • There is no network protocol, authentication or user management, so exposing it to remote clients means writing and securing your own service around it.
  • It is built for scans and aggregations, not for many small transactions, so a workload of high-frequency single-row inserts and updates performs badly compared with SQLite or Postgres.
  • Storage files are backwards compatible but not forwards compatible, so a file written by a newer version cannot be read by an older one and every consumer of a shared file must be upgraded together.
  • Query memory settings matter: some operations still need to hold significant state, so an under-configured memory limit turns a large join or a high-cardinality aggregation into a spill-heavy query or an out-of-memory failure rather than a slow success.

Vault

  • Vault 1.15.0 and later is licensed under the Business Source License 1.1, not an OSI open source licence, with IBM Corporation as licensor
  • The Additional Use Grant forbids offering Vault to third parties on a hosted or embedded basis in a paid product that competes with IBM's paid versions of Vault
  • Each version only converts to MPL 2.0 four years after that version is published, and the Change Date is tracked per version
  • Replication, HSM support, namespaces, performance standby nodes, FIPS builds, control group authorisation, multi-factor authentication, secrets sync and lease count quotas all require a Vault Enterprise licence
  • A Vault Enterprise licence must be applied to the cluster before any Enterprise feature can be used

Pricing, plan by plan

DuckDB

Free

No published plan breakdown. See the DuckDB review.

Vault

Free
  • Open SourceFree
    • Secrets management
    • Encryption as a service
    • Identity management
  • EnterpriseFree
    • Advanced features
    • Premium support
    • Dedicated updates

Which should you pick?

Choose DuckDB if

  • You need in-process execution.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, WebAssembly.
  • You also want vectorised columnar engine.
DuckDB review

Choose Vault if

  • You need secrets management.
  • You want to start without paying.
  • You work on Linux, Windows, Mac, Cloud.
  • You also want encryption.
Vault review

Questions people ask

Is DuckDB or Vault better?
Neither clearly leads. DuckDB starts at Free and Vault at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, DuckDB or Vault?
DuckDB starts at Free and Vault at Free.
Does DuckDB or Vault run on more platforms?
DuckDB runs on Linux, macOS, Windows, WebAssembly. Vault runs on Linux, Windows, Mac, Cloud.
Can I use DuckDB for free?
Both have a free tier, so you can try either at no cost before committing.
What is DuckDB best used for?
DuckDB is most often used for transformation steps in a data pipeline that would otherwise need spark, replaced by sql over parquet in a single process, analytical queries embedded in an application or a dashboard where shipping a database server alongside it is not acceptable, local exploration of files that are too large for a pandas dataframe but far too small to justify a warehouse, continuous integration and testing of analytical sql, where a real engine can run in the test process without provisioning anything. Of those, transformation steps in a data pipeline that would otherwise need spark, replaced by sql over parquet in a single process and analytical queries embedded in an application or a dashboard where shipping a database server alongside it is not acceptable are not what Vault is typically brought in for.
What can DuckDB do that Vault cannot?
DuckDB covers In-process execution, Vectorised columnar engine, Direct file querying, Zero dependencies. Vault covers Secrets management, Encryption, Authentication, Authorization.

Answered from the vendors’ own pages

DuckDB: Can multiple applications share one DuckDB database?

Not for writing. One process holds the database read-write; others may attach read-only and will not see later writes. Shared multi-writer access needs a different database or a table format with a catalogue.

Vault: Is HashiCorp Vault free to use?

Yes, Vault is available as a free, open-source project. The community version includes secrets management, certificate generation and rotation, encryption services, and credential management. Vault Enterprise is a commercial offering with additional features.

Source
DuckDB: Is it a replacement for a data warehouse?

For single-node analytical workloads up to a few hundred gigabytes it very often is. It is not a replacement when many concurrent users need a shared, governed, always-on service.

Vault: What are the differences between open-source Vault and Vault Enterprise?

Open-source Vault is free and self-hosted. Vault Enterprise includes additional features and commercial support. HashiCorp also offers Vault Dedicated on the HashiCorp Cloud Platform as a fully managed cloud option.

Source
DuckDB: Do I have to load data into it?

No. It queries Parquet, CSV, JSON and Arrow in place, including on object storage. Its own storage format is optional and mainly useful when you want indexes, constraints and faster repeated access.

Vault: Can I try HashiCorp Cloud Platform Vault without payment?

Yes, HashiCorp offers a free trial option for HCP Vault Dedicated. New users also receive a $500 credit to use across HashiCorp Cloud Platform services.

Source
DuckDB: What is MotherDuck's relationship to it?

MotherDuck is a separate company offering a managed and hybrid service built on the DuckDB engine. DuckDB itself remains MIT-licensed and independent of it, with the IP held by the DuckDB Foundation.

Vault: What does Vault manage and protect?

Vault provides identity-based secrets management for users, machines, services, and AI agents. It automates authentication and authorization for access to secrets, passwords, certificates, encryption keys, and other sensitive data across your infrastructure.

Source
DuckDB: Is it suitable for OLTP?

No. It is designed for analytical scans. For transactional workloads with frequent small writes, SQLite or Postgres is the right tool.

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