postgres.md

description	PostgreSQL Data Connector Documentation

PostgreSQL Data Connector

PostgreSQL is an advanced open-source relational database management system known for its robustness, 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:
      pg_host: localhost
      pg_port: 5432
      pg_db: my_database
      pg_user: my_user
      pg_pass: ${secrets:my_pg_pass}

Configuration

from

The from field takes the form postgres:my_table where my_table is the table identifier 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: ...

{% hint style="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. {% endhint %}

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: ...

SELECT COUNT(*) FROM cool_dataset;

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

params

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

Parameter Name	Description
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 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) - requires SSL, valid root certificate, and matching server host name; verify-ca - requires TLS and valid root certificate; require - requires TLS; prefer - tries TLS but connects insecurely if not supported; disable - does not use TLS.
pg_sslrootcert	Optional parameter specifying the path to a custom PEM certificate that the connector will trust.
connection_pool_size	Optional. The maximum number of connections to keep open in the connection pool. Default is 10.

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	LargeUtf8
timestamp	Timestamp(Nanosecond, None)
timestampz	Timestamp(Nanosecond, TimeZone
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

{% hint style="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). {% endhint %}

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}

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

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}