The PostgreSQL offline store provides support for reading PostgreSQLSources.
- Entity dataframes can be provided as a SQL query or can be provided as a Pandas dataframe. A Pandas dataframes will be uploaded to Postgres as a table in order to complete join operations.
The PostgreSQL offline store does not achieve full test coverage. Please do not assume complete stability.
In order to use this offline store, you'll need to run pip install 'feast[postgres]'. You can get started by then running feast init -t postgres.
{% code title="feature_store.yaml" %}
project: my_project
registry: data/registry.db
provider: local
offline_store:
type: postgres
host: DB_HOST
port: DB_PORT
database: DB_NAME
db_schema: DB_SCHEMA
user: DB_USERNAME
password: DB_PASSWORD
sslmode: verify-ca
sslkey_path: /path/to/client-key.pem
sslcert_path: /path/to/client-cert.pem
sslrootcert_path: /path/to/server-ca.pem
entity_select_mode: temp_table
online_store:
path: data/online_store.db{% endcode %}
Note that sslmode defaults to require, which encrypts the connection without certificate verification. To disable SSL (e.g. for local development), set sslmode: disable. For certificate verification, set sslmode to verify-ca or verify-full and provide the corresponding sslrootcert_path (and optionally sslcert_path and sslkey_path for mutual TLS).
The full set of configuration options is available in PostgreSQLOfflineStoreConfig.
Additionally, a new optional parameter entity_select_mode was added to tell how Postgres should load the entity data. By default(temp_table), a temporary table is created and the entity data frame or sql is loaded into that table. A new value of embed_query was added to allow directly loading the SQL query into a CTE, providing improved performance and skipping the need to CREATE and DROP the temporary table.
The set of functionality supported by offline stores is described in detail here. Below is a matrix indicating which functionality is supported by the PostgreSQL offline store.
| Postgres | |
|---|---|
get_historical_features (point-in-time correct join) |
yes |
pull_latest_from_table_or_query (retrieve latest feature values) |
yes |
pull_all_from_table_or_query (retrieve a saved dataset) |
yes |
offline_write_batch (persist dataframes to offline store) |
no |
write_logged_features (persist logged features to offline store) |
no |
Below is a matrix indicating which functionality is supported by PostgreSQLRetrievalJob.
| Postgres | |
|---|---|
| export to dataframe | yes |
| export to arrow table | yes |
| export to arrow batches | no |
| export to SQL | yes |
| export to data lake (S3, GCS, etc.) | yes |
| export to data warehouse | yes |
| export as Spark dataframe | no |
| local execution of Python-based on-demand transforms | yes |
| remote execution of Python-based on-demand transforms | no |
| persist results in the offline store | yes |
| preview the query plan before execution | yes |
| read partitioned data | yes |
To compare this set of functionality against other offline stores, please see the full functionality matrix.