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: localhost
pg_port: 5432
pg_db: my_database
pg_user: my_user
pg_pass: ${secrets:my_pg_pass}
pg_sslmode: require
Specify different secrets for a PostgreSQL source and acceleration:
datasets:
- from: spice.ai:path.to.my_dataset
name: my_dataset
params:
pg_host: localhost
pg_port: 5432
pg_db: data_store
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}
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)
intoCAST (SUM(int_col) as BIGINT
.
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) |