sql-persistence.md

SQL persistence

Every store in the EDC, intended as persistence for state, comes out of the box with two implementations:

• in-memory
• sql (postgresql dialect)

By default, the in-memory stores are provided by the dependency injection, the sql implementations can be used by simply registering the relative extensions (e.g. asset-index-sql, contract-negotiation-store-sql, ...).

Configuration

DataSources

For using sql extensions, a DataSource is needed, and it should be registered on the DataSourceRegistry service.

The sql-pool-apache-commons extension takes care to create and register pooled data sources starting from configuration. It expects at least one data source called default that can be configured with Vault keys:

edc.datasource.default.url=...
edc.datasource.default.name=...
edc.datasource.default.password=...

(note: if no vault entries are found for such keys, they will be obtained from the configuration).

Other datasources can be defined using the same settings structure:

edc.datasource.<datasource-name>.url=...
edc.datasource.<datasource-name>.name=...
edc.datasource.<datasource-name>.password=...

<datasource-name> can be a string that then can be used by the stores configuration to use specific data sources.

Using custom datasource in stores

Using a custom datasource in a store can be done by configuring the setting:

edc.sql.store.<store-context>.datasource=<datasource-name>

This way the <store-context> (that could be asset, contractnegotiation...) will use the <datasource-name> datasource.