Listening PostgreSQL Logical Replication

September 10, 2022 · View on GitHub

This repo contains an example under the example folder for listening to Postgresql Logical Replication using the dart postgres package (pub | repo) -- version 2.5.0 or above. This allows listening to changes in PostgreSQL database in the following manner:

Insert changes (one row):

{
    "change": [
            {
                "kind": "insert",
                "schema": "public",
                "table": "temp",
                "columnnames": ["id", "val"],
                "columntypes": ["integer", "text"],
                "columnvalues": [58, "new value"]
            }
    ]
}

Update changes (two rows):

{
    "change": [
            {
                    "kind": "update",
                    "schema": "public",
                    "table": "temp",
                    "columnnames": ["id", "val"],
                    "columntypes": ["integer", "text"],
                    "columnvalues": [2, "updated value"],
                    "oldkeys": {
                            "keynames": ["id"],
                            "keytypes": ["integer"],
                            "keyvalues": [2]
                    }
            }
            ,{
                    "kind": "update",
                    "schema": "public",
                    "table": "temp",
                    "columnnames": ["id", "val"],
                    "columntypes": ["integer", "text"],
                    "columnvalues": [1, "updated value"],
                    "oldkeys": {
                            "keynames": ["id"],
                            "keytypes": ["integer"],
                            "keyvalues": [1]
                    }
            }
    ]
}

Delete changes (one row):

{
    "change": [
            {
                    "kind": "delete",
                    "schema": "public",
                    "table": "temp",
                    "oldkeys": {
                            "keynames": ["id"],
                            "keytypes": ["integer"],
                            "keyvalues": [51]
                    }
            }
    ]
}

Further Readings