ADBC Driver for Apache Druid¶

Driver Version v0.1.0-alpha.1 Release Date 2026-09-14 Tested With Apache Druid 37

Warning

This is documentation for a prerelease version.

This driver provides access to Apache Druid , a high-performance, real-time analytics database.

Note

This project is not part of the Apache Software Foundation.

Installation & Quickstart¶

The Druid driver can be installed with dbc :

dbc install --pre druid

Connecting¶

To use the driver, provide the URI of a Druid database as the uri option.

from adbc_driver_manager import dbapi

connection = dbapi.connect(
    driver="druid",
    db_kwargs={
        "uri": "druid://localhost:8888?tls=false",
    },
)

Note: The example above is for Python using the adbc-driver-manager package but the process will be similar for other driver managers. See adbc-quickstarts .

Connection String Format¶

druid://[username[:password]@]host[:port][/path][?tls=true|false&tls_ca=path]

Components:

Scheme: druid:// (also accepts http:// and https://)
username: HTTP Basic authentication username (optional)
password: HTTP Basic authentication password (optional; requires a username)
host: Druid Router or Broker host (required)
port: Service port (optional; defaults to 443 for HTTPS and 80 for HTTP)
path: Base path when Druid is exposed through a reverse proxy (optional)
tls: Whether to use HTTPS; defaults to true and only applies to druid:// URIs
tls_ca: Path to a PEM CA certificate used to verify the server

HTTPS/SSL Configuration¶

The druid:// scheme uses HTTPS and the system trust store by default. To connect to a plaintext Druid endpoint, set tls=false.

Examples:

druid://druid.example.com → HTTPS on port 443
druid://druid.example.com:9088 → HTTPS on port 9088
druid://localhost:9088?tls_ca=/path/to/ca.crt → HTTPS with a custom CA
druid://localhost:8888?tls=false → HTTP on port 8888
https://druid.example.com:9088 → Explicit HTTPS URL
http://localhost:8888 → Explicit HTTP URL

Reserved characters in credentials must be percent-encoded. For example, @ becomes %40. Credentials can instead be supplied with the ADBC username and password database options; those options override credentials in the URI and are recommended when the URI may appear in logs or shell history.

Feature & Type Support¶

Feature		Apache Druid
Bind Parameters		✅
Bulk Ingestion	Create	❌
	Append	❌
	Create/Append	❌
	Replace	❌
	Temporary Table	❌
	Target Catalog	❌
	Target Schema	❌
	Non-nullable fields are marked NOT NULL	❌
Catalog (GetObjects)	depth=catalogs	❌
	depth=db_schemas	❌
	depth=tables	❌
	depth=columns (all)	❌
Get Parameter Schema		❌
Get Table Schema		✅
Prepared Statements		❌
Transactions		❌

Types¶

Database to Arrow¶

Database Type	Apache Druid
BIGINT	int64
BOOLEAN	bool
DATE	date32[day]
DOUBLE PRECISION	double
INT	int64
NUMERIC	double ⚠️ [1]
REAL	float
SMALLINT	❌
TIME	❌
TIMESTAMP	timestamp[ms]
TIMESTAMP WITH TIME ZONE	❌
TIMESTAMP(0)	❌
TIMESTAMP(0) WITH TIME ZONE	❌
TIMESTAMP(p) (1 <= p <= 3)	timestamp[ms]
TIMESTAMP(p) (1 <= p <= 3) WITH TIME ZONE	❌
TIMESTAMP(p) (4 <= p <= 6)	❌
TIMESTAMP(p) (4 <= p <= 6) WITH TIME ZONE	❌
TIMESTAMP(p) (7 <= p <= 9)	❌
TIMESTAMP(p) (7 <= p <= 9) WITH TIME ZONE	❌
VARBINARY	❌
VARCHAR	string

Arrow to Database¶

Arrow Type	Apache Druid Type
	Bind
	binary	❌
binary_view	❌
bool	BOOLEAN
date32[day]	DATE ⚠️ [2]
decimal128	NUMERIC ⚠️ [1]
double	DOUBLE PRECISION
fixed_size_binary	❌
float	REAL
halffloat	REAL
int16	SMALLINT
int32	INT
int64	BIGINT
large_binary	❌
large_string	VARCHAR
string	VARCHAR
string_view	VARCHAR
time32[ms]	❌
time32[s]	❌
time64[ns]	❌
time64[us]	❌
timestamp[ms]	TIMESTAMP(3) ⚠️ [3]
timestamp[ms] (with time zone)	❌
timestamp[ns]	❌
timestamp[ns] (with time zone)	❌
timestamp[s]	❌
timestamp[s] (with time zone)	❌
timestamp[us]	❌
timestamp[us] (with time zone)	❌

Options¶

Statement Options¶

druid.statement.<option_name>

Type: string, integer, or double.

Sets a Druid SQL query-context parameter. The driver removes the druid.statement. prefix and sends the remaining option name to Druid. For example, druid.statement.timeout sets Druid’s timeout context parameter. Byte values are not supported.

Compatibility¶

This driver was tested on:

Apache Druid 37.0.0