The PostgreSQL connector is a Conduit plugin. It provides both, a source and a destination PostgresSQL connectors.
The Postgres Source Connector connects to a database with the provided url and starts creating records for each change
detected in the provided tables.
Upon starting, the source takes a snapshot of the provided tables in the database, then switches into CDC mode. In CDC mode, the plugin reads from a buffer of CDC events.
When the connector first starts, snapshot mode is enabled. The connector acquires a read-only lock on the tables, and then reads all rows of the tables into Conduit. Once all rows in that initial snapshot are read the connector releases its lock and switches into CDC mode.
This behavior is enabled by default, but can be turned off by adding "snapshotMode":"never" to the Source
configuration.
This connector implements CDC features for PostgreSQL by creating a logical replication slot and a publication that
listens to changes in the configured tables. Every detected change is converted into a record and returned in the call to
Read. If there is no record available at the moment Read is called, it blocks until a record is available or the
connector receives a stop signal.
When the connector switches to CDC mode, it attempts to run the initial setup commands to create its logical replication slot and publication. It will connect to an existing slot if one with the configured name exists.
The Postgres user specified in the connection URL must have sufficient privileges to run all of these setup commands, or it will fail.
Example configuration for CDC features:
{
"url": "url",
"tables": "records",
"cdcMode": "logrepl",
"logrepl.publicationName": "meroxademo",
"logrepl.slotName": "meroxademo"
}logrepl.autoCleanup to false.
The connector will automatically look up the primary key column for the specified tables. If that can't be determined, the connector will return an error.
| name | description | required | default |
|---|---|---|---|
url |
Connection string for the Postgres database. | true | |
tables |
List of table names to read from, separated by comma. Example: "employees,offices,payments". Using * will read from all public tables. |
true | |
snapshotMode |
Whether or not the plugin will take a snapshot of the entire table before starting cdc mode (allowed values: initial or never). |
false | initial |
cdcMode |
Determines the CDC mode (allowed values: auto, logrepl). |
false | auto |
logrepl.publicationName |
Name of the publication to listen for WAL events. | false | conduitpub |
logrepl.slotName |
Name of the slot opened for replication events. | false | conduitslot |
logrepl.autoCleanup |
Whether or not to cleanup the replication slot and pub when connector is deleted | false | true |
table |
List of table names to read from, separated by comma. Deprecated: use tables instead. |
false |
The Postgres Destination takes a record.Record and parses it into a valid SQL query. The Destination is designed to
handle different payloads and keys. Because of this, each record is individually parsed and upserted.
If the target table already contains a record with the same key, the Destination will upsert with its current received values. Because Keys must be unique, this can overwrite and thus potentially lose data, so keys should be assigned correctly from the Source.
If there is no key, the record will be simply appended.
| name | description | required | default |
|---|---|---|---|
url |
Connection string for the Postgres database. | true | |
table |
Table name. It can contain a Go template that will be executed for each record to determine the table. By default, the table is the value of the opencdc.collection metadata field. |
false | {{ index .Metadata "opencdc.collection" }} |
key |
Key represents the column name for the key used to identify and update existing rows. | false |
Run make test to run all the unit and integration tests, which require Docker to be installed and running. The command
will handle starting and stopping docker containers for you.