spiceai/docs

spiceai/docs/README.md

title: 'PostgreSQL Data Connector' sidebar_label: 'PostgreSQL Data Connector' description: 'PostgreSQL Data Connector Documentation' tags:

data-connectors
postgres
write

PostgreSQL is an advanced open-source relational database management system known for its reliability, extensibility, and support for SQL compliance.

The PostgreSQL Server Data Connector enables federated/accelerated SQL queries on data stored in PostgreSQL databases.

datasets:
  - from: postgres:my_table
    name: my_dataset
    params: ...

datasets:
  - from: postgres:my_table
    name: my_dataset
    params: ...

Quickstart

Connect to a local PostgreSQL database and accelerate a table for fast local queries:

version: v1
kind: Spicepod
name: pg_demo

datasets:
  - from: postgres:public.customers
    name: customers
    params:
      pg_host: localhost
      pg_port: "5432"
      pg_db: mydb
      pg_user: spice_reader
      pg_pass: ${secrets:PG_PASSWORD}
    acceleration:
      enabled: true

version: v1
kind: Spicepod
name: pg_demo

datasets:
  - from: postgres:public.customers
    name: customers
    params:
      pg_host: localhost
      pg_port: "5432"
      pg_db: mydb
      pg_user: spice_reader
      pg_pass: ${secrets:PG_PASSWORD}
    acceleration:
      enabled: true

echo "PG_PASSWORD=your_password" > .env

echo "PG_PASSWORD=your_password" > .env

Start Spice and query the data:

spice run
# In another terminal:
spice sql
sql> SELECT count(*) FROM customers;

spice run
# In another terminal:
spice sql
sql> SELECT count(*) FROM customers;

Configuration

`from`

The from field takes the form postgres:my_table where my_table is the table identifer in the PostgreSQL server to read from.

The fully-qualified table name (database.schema.table) can also be used in the from field.

datasets:
  - from: postgres:my_database.my_schema.my_table
    name: my_dataset
    params: ...

datasets:
  - from: postgres:my_database.my_schema.my_table
    name: my_dataset
    params: ...

:::info Unquoted identifiers are normalized to lowercase. To reference a table or schema with mixed-case characters, wrap each case-sensitive part in double quotes: postgres:my_schema."MixedCaseTable". See Identifier Case Sensitivity (opens in a new tab). :::

`name`

The dataset name. This will be used as the table name within Spice.

Example:

datasets:
  - from: postgres:my_database.my_schema.my_table
    name: cool_dataset
    params: ...

datasets:
  - from: postgres:my_database.my_schema.my_table
    name: cool_dataset
    params: ...

SELECT COUNT(*) FROM cool_dataset;

SELECT COUNT(*) FROM cool_dataset;

+----------+
| count(*) |
+----------+
| 6001215  |
+----------+

+----------+
| count(*) |
+----------+
| 6001215  |
+----------+

`params`

The connection to PostgreSQL can be configured by providing the following params:

Parameter Name	Description
`pg_connection_string`	Optional. The connection string to use to connect to the PostgreSQL server. This can be used instead of providing individual connection parameters.
`pg_host`	The hostname of the PostgreSQL server.
`pg_port`	The port of the PostgreSQL server.
`pg_db`	The name of the database to connect to.
`pg_user`	The username to connect with.
`pg_pass`	The password to connect with. Use the secret replacement syntax (opens in a new tab) to load the password from a secret store, e.g. `${secrets:my_pg_pass}`.
`pg_sslmode`	Optional. Specifies the SSL/TLS behavior for the connection, supported values: `verify-full`: (default) This mode requires an SSL connection, a valid root certificate, and the server host name to match the one specified in the certificate.`verify-ca`: This mode requires a TLS connection and a valid root certificate.`require`: This mode requires a TLS connection.`prefer`: This mode will try to establish a secure TLS connection if possible, but will connect insecurely if the server does not support TLS.`disable`: This mode will not attempt to use a TLS connection, even if the server supports it.
`pg_sslrootcert`	Optional. Path to a custom PEM certificate file, or inline PEM content, that the connector will trust when `pg_sslmode` is `verify-ca` or `verify-full`. Both spellings are accepted on the federated read/query path and on the WAL replication transport (`refresh_mode: changes`); a value containing a `-----BEGIN CERTIFICATE-----` block is read as PEM content, and anything else as a path.
`pg_connection_pool_min_idle`	Optional. The minimum number of idle connections to keep open in the pool. Default is `1`.
`connection_pool_size`	Optional. The maximum number of connections created in the connection pool. Default is `5`.

Replication parameters

The following parameters configure PostgreSQL logical replication (opens in a new tab) (WAL streaming) when using refresh_mode: changes:

Parameter Name	Description
`pg_replication_slot`	Optional. Name of the replication slot to create/reuse. Must match `[a-z0-9_]{1,63}` and must not be the reserved name `pg_conflict_detection`. Defaults to `spice_<dataset>_<dataset-hash>_<instance-hash>`. Each Spice replica MUST have its own unique slot.
`pg_publication`	Optional. Name of the publication to create/reuse. Defaults to `spice_<dataset>_<dataset-hash>_pub`, or `<slot>_pub` when `pg_replication_slot` is set. Shared across replicas for the same dataset.
`pg_replication_initial_snapshot`	Optional. When `refresh_mode: changes` first loads the table's existing rows: `auto` (default) snapshots a freshly-created replication slot and resumes an existing one without a snapshot; `disabled` streams WAL changes only; `always` snapshots on every start, including slot resume. The legacy booleans `true`/`false` map to `auto`/`disabled`. Default: `auto`.
`pg_replication_temporary_slot`	Deprecated and ignored. The replication slot is always durable. Setting it logs a deprecation warning and has no other effect. To stop an unused slot retaining WAL on the source, drop it with `SELECT pg_drop_replication_slot('<slot_name>')`.
`pg_replication_status_interval`	Optional. How often to send StandbyStatusUpdate to Postgres (e.g. `10s`). Default: `10s`.
`pg_replication_ready_lag`	Optional. For `refresh_mode: changes`, the dataset is marked Ready once its replication lag (now minus the newest applied commit's source time) falls below this. Default: `2s`.
`pg_replication_bootstrap_batch_size`	Optional. Number of rows per emitted batch during the initial replication snapshot. Default: `8192`. Maximum: `1048576`.
`pg_replication_member_channel_capacity`	Optional. Shared-slot only: envelopes buffered per member table before the shared replication pump back-pressures. Default: `1024`. Maximum: `1048576`.

:::warning[pg_sslmode differs on the WAL replication transport]

The pg_sslmode default of verify-full documented above applies to the federated read/query path. On the WAL replication transport used by refresh_mode: changes, an unset pg_sslmode defaults to prefer, which negotiates a plaintext connection (no certificate verification). Set pg_sslmode to require, verify-ca, or verify-full to force TLS on the WAL stream — see pg_sslmode for WAL streaming (opens in a new tab).

This applies to the discrete-parameter path. When the connection is configured with pg_connection_string and the string omits sslmode, the WAL transport defaults to verify-full — see Connecting with pg_connection_string (opens in a new tab).

pg_sslrootcert behaves the same on both transports: a value containing a -----BEGIN CERTIFICATE----- block is treated as inline PEM content, and any other value as a path to a PEM file. Content that arrives through a channel that does not preserve real newlines — a single-line environment variable, a JSON string pasted verbatim — carries them as the two characters \n, which are restored before the certificate is parsed.

:::

Types

The table below shows the PostgreSQL data types supported, along with the type mapping to Apache Arrow types in Spice.

PostgreSQL Type	Arrow Type
`int2`	`Int16`
`int4`	`Int32`
`int8`	`Int64`
`money`	`Int64`
`float4`	`Float32`
`float8`	`Float64`
`numeric`	`Decimal128`
`text`	`Utf8`
`varchar`	`Utf8`
`bpchar`	`Utf8`
`uuid`	`Utf8`
`bytea`	`Binary`
`bool`	`Boolean`
`json`	`Utf8`
`timestamp`	`Timestamp(Nanosecond, None)`
`timestamptz`	`Timestamp(Nanosecond, UTC)`
`date`	`Date32`
`time`	`Time64(Nanosecond)`
`interval`	`Interval(MonthDayNano)`
`point`	`FixedSizeList(Float64[2])`
`int2[]`	`List(Int16)`
`int4[]`	`List(Int32)`
`int8[]`	`List(Int64)`
`float4[]`	`List(Float32)`
`float8[]`	`List(Float64)`
`text[]`	`List(Utf8)`
`bool[]`	`List(Boolean)`
`bytea[]`	`List(Binary)`
`geometry`	`Binary`
`geography`	`Binary`
`enum`	`Dictionary(Int8, Utf8)`
Composite Types	`Struct`

:::info

The Postgres federated queries may result in unexpected result types due to the difference in DataFusion and Postgres size increase rules. Explicitly specify the expected output type of aggregation functions when writing queries involving Postgres tables in Spice. For example, rewrite SUM(int_col) into CAST (SUM(int_col) as BIGINT).

:::

Write Support

The PostgreSQL connector supports writing data to PostgreSQL tables using SQL INSERT INTO (opens in a new tab), UPDATE, and DELETE FROM statements.

To enable writes, set access: read_write on the dataset:

datasets:
  - from: postgres:public.events
    name: events
    access: read_write
    params:
      pg_host: localhost
      pg_port: '5432'
      pg_db: mydb
      pg_user: spice_writer
      pg_pass: ${secrets:PG_PASSWORD}

datasets:
  - from: postgres:public.events
    name: events
    access: read_write
    params:
      pg_host: localhost
      pg_port: '5432'
      pg_db: mydb
      pg_user: spice_writer
      pg_pass: ${secrets:PG_PASSWORD}

-- Insert rows
INSERT INTO events (id, name, amount)
VALUES (1, 'Alice', 100.0), (2, 'Bob', 200.0);

-- Update rows
UPDATE events SET amount = 150.0 WHERE id = 1;

-- Delete rows
DELETE FROM events WHERE id = 2;

-- Insert rows
INSERT INTO events (id, name, amount)
VALUES (1, 'Alice', 100.0), (2, 'Bob', 200.0);

-- Update rows
UPDATE events SET amount = 150.0 WHERE id = 1;

-- Delete rows
DELETE FROM events WHERE id = 2;

Write modes with acceleration

When PostgreSQL is used as the federated source for an accelerated dataset, acceleration.write_mode selects how writes propagate between the local accelerator and PostgreSQL:

write_through (default) — writes are sent to PostgreSQL synchronously. The client receives an ACK only after the source commits. The local accelerator is updated via the configured refresh path. Choose this for ACID guarantees.
write_back — writes are applied to the local accelerator first (fast ACK), then forwarded asynchronously to PostgreSQL. Choose this for write throughput when eventual consistency at the source is acceptable.

acceleration.refresh_mode: changes is supported for access: read_write datasets: writes go to PostgreSQL and the WAL replication stream applies the resulting changes back to the accelerator.

datasets:
  - from: postgres:public.events
    name: events
    access: read_write
    params:
      pg_host: localhost
      pg_port: '5432'
      pg_db: mydb
      pg_user: spice_writer
      pg_pass: ${secrets:PG_PASSWORD}
      # Replication-mode parameters (see Configuration above)
      pg_publication: spice_pub
      pg_replication_slot: spice_slot
    acceleration:
      engine: duckdb
      mode: file
      refresh_mode: changes
      write_mode: write_through # default; use write_back for fast async writes

datasets:
  - from: postgres:public.events
    name: events
    access: read_write
    params:
      pg_host: localhost
      pg_port: '5432'
      pg_db: mydb
      pg_user: spice_writer
      pg_pass: ${secrets:PG_PASSWORD}
      # Replication-mode parameters (see Configuration above)
      pg_publication: spice_pub
      pg_replication_slot: spice_slot
    acceleration:
      engine: duckdb
      mode: file
      refresh_mode: changes
      write_mode: write_through # default; use write_back for fast async writes

For more details, see Data Ingestion (opens in a new tab).

Examples

Connecting using Username/Password

datasets:
  - from: postgres:my_database.my_schema.my_table
    name: my_dataset
    params:
      pg_host: localhost
      pg_port: 5432
      pg_db: my_database
      pg_user: my_user
      pg_pass: ${secrets:my_pg_pass}

datasets:
  - from: postgres:my_database.my_schema.my_table
    name: my_dataset
    params:
      pg_host: localhost
      pg_port: 5432
      pg_db: my_database
      pg_user: my_user
      pg_pass: ${secrets:my_pg_pass}

Connect using SSL

datasets:
  - from: postgres:my_database.my_schema.my_table
    name: my_dataset
    params:
      pg_host: localhost
      pg_port: 5432
      pg_db: my_database
      pg_user: my_user
      pg_pass: ${secrets:my_pg_pass}
      pg_sslmode: verify-ca
      pg_sslrootcert: ./custom_cert.pem

datasets:
  - from: postgres:my_database.my_schema.my_table
    name: my_dataset
    params:
      pg_host: localhost
      pg_port: 5432
      pg_db: my_database
      pg_user: my_user
      pg_pass: ${secrets:my_pg_pass}
      pg_sslmode: verify-ca
      pg_sslrootcert: ./custom_cert.pem

Separate dataset/accelerator secrets

Specify different secrets for a PostgreSQL source and acceleration:

datasets:
  - from: postgres:my_schema.my_table
    name: my_dataset
    params:
      pg_host: localhost
      pg_port: 5432
      pg_db: my_database
      pg_user: my_user
      pg_pass: ${secrets:pg1_pass}
    acceleration:
      engine: postgres
      params:
        pg_host: localhost
        pg_port: 5433
        pg_db: acceleration
        pg_user: two_user_two_furious
        pg_pass: ${secrets:pg2_pass}

datasets:
  - from: postgres:my_schema.my_table
    name: my_dataset
    params:
      pg_host: localhost
      pg_port: 5432
      pg_db: my_database
      pg_user: my_user
      pg_pass: ${secrets:pg1_pass}
    acceleration:
      engine: postgres
      params:
        pg_host: localhost
        pg_port: 5433
        pg_db: acceleration
        pg_user: two_user_two_furious
        pg_pass: ${secrets:pg2_pass}

Secrets

Spice integrates with multiple secret stores to help manage sensitive data securely. For detailed information on supported secret stores, refer to the secret stores documentation (opens in a new tab). Additionally, learn how to use referenced secrets in component parameters by visiting the using referenced secrets guide (opens in a new tab).

Cookbook

A cookbook recipe to configure PostgreSQL as a data connector in Spice. Postgres Data Connector (opens in a new tab)
A cookbook recipe to configure AWS RDS for PostgreSQL as a data connector in Spice. AWS RDS for PostgreSQL (opens in a new tab)
A cookbook recipe to configure Supabase as a data connector in Spice. Supabase (PostgreSQL Data Connector) (opens in a new tab)