PostgreSQL Data Accelerator

To use PostgreSQL as Data Accelerator, specify postgres as the engine for acceleration.

datasets:
  - from: spice.ai:path.to.my_dataset
    name: my_dataset
    acceleration:
      engine: postgres

Configuration

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

• 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) 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 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.

Configuration params are provided either in the acceleration section of a dataset.

datasets:
  - from: spice.ai:path.to.my_dataset
    name: my_dataset
    acceleration:
      engine: postgres
      params:
        pg_host: my_db_host
        pg_port: 5432
        pg_db: my_database
        pg_user: my_user
        pg_pass: ${secrets:my_pg_pass}
        pg_sslmode: require

Arrow to PostgreSQL Type Mapping

The table below lists the supported Apache Arrow data types and their mappings to PostgreSQL types when stored

Arrow Type	sea_query ColumnType	PostgreSQL Type
Int8	TinyInteger	smallint
Int16	SmallInteger	smallint
Int32	Integer	integer
Int64	BigInteger	bigint
UInt8	TinyUnsigned	smallint
UInt16	SmallUnsigned	smallint
UInt32	Unsigned	bigint
UInt64	BigUnsigned	numeric
Decimal128 / Decimal256	Decimal	decimal
Float32	Float	real
Float64	Double	double precision
Utf8 / LargeUtf8	Text	text
Boolean	Boolean	bool
Binary / LargeBinary	VarBinary	bytea
FixedSizeBinary	Binary	bytea
Timestamp (no Timezone)	Timestamp	timestamp without time zone
Timestamp (with Timezone)	TimestampWithTimeZone	timestamp with time zone
Date32 / Date64	Date	date
Time32 / Time64	Time	time
Interval	Interval	interval
Duration	BigInteger	bigint
List / LargeList / FixedSizeList	Array	array
Struct	N/A	Composite (Custom type)

LIMITATIONS

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