graphql-engine/server/src-rsr/init_pg_source.sql

/* We define our own uuid generator function that uses gen_random_uuid() underneath.
   Since the column default is not directly referencing gen_random_uuid(),
   it prevents the column default to be dropped when pgcrypto or public schema is dropped unwittingly.

   See https://github.com/hasura/graphql-engine/issues/4217
 */
CREATE OR REPLACE FUNCTION hdb_catalog.gen_hasura_uuid() RETURNS uuid AS
  -- We assume gen_random_uuid() is available in the search_path.
  -- This may not be true but we can't do much till https://github.com/hasura/graphql-engine/issues/3657
'select gen_random_uuid()' LANGUAGE SQL;

CREATE TABLE hdb_catalog.hdb_source_catalog_version(
  version TEXT NOT NULL,
  upgraded_on TIMESTAMPTZ NOT NULL
);

CREATE UNIQUE INDEX hdb_source_catalog_version_one_row
ON hdb_catalog.hdb_source_catalog_version((version IS NOT NULL));

CREATE TABLE hdb_catalog.event_log
(
  id TEXT DEFAULT hdb_catalog.gen_hasura_uuid() PRIMARY KEY,
  schema_name TEXT NOT NULL,
  table_name TEXT NOT NULL,
  trigger_name TEXT NOT NULL,
  payload JSONB NOT NULL,
  delivered BOOLEAN NOT NULL DEFAULT FALSE,
  error BOOLEAN NOT NULL DEFAULT FALSE,
  tries INTEGER NOT NULL DEFAULT 0,
  created_at TIMESTAMP DEFAULT NOW(),
  /* when locked IS NULL the event is unlocked and can be processed */
  locked TIMESTAMPTZ,
  next_retry_at TIMESTAMP,
  archived BOOLEAN NOT NULL DEFAULT FALSE
);

/* This powers `archiveEvents` */
CREATE INDEX ON hdb_catalog.event_log (trigger_name);
/* This index powers `fetchEvents` */
CREATE INDEX event_log_fetch_events
  ON hdb_catalog.event_log (locked NULLS FIRST, next_retry_at NULLS FIRST, created_at)
  WHERE delivered = 'f' 
    and error = 'f'
    and archived = 'f'
;


CREATE TABLE hdb_catalog.event_invocation_logs
(
  id TEXT DEFAULT hdb_catalog.gen_hasura_uuid() PRIMARY KEY,
  event_id TEXT,
  status INTEGER,
  request JSON,
  response JSON,
  created_at TIMESTAMP DEFAULT NOW(),

  FOREIGN KEY (event_id) REFERENCES hdb_catalog.event_log (id)
);

CREATE INDEX ON hdb_catalog.event_invocation_logs (event_id);

CREATE OR REPLACE FUNCTION
  hdb_catalog.insert_event_log(schema_name text, table_name text, trigger_name text, op text, row_data json)
  RETURNS text AS $$
  DECLARE
    id text;
    payload json;
    session_variables json;
    server_version_num int;
    trace_context json;
  BEGIN
    id := gen_random_uuid();
    server_version_num := current_setting('server_version_num');
    IF server_version_num >= 90600 THEN
      session_variables := current_setting('hasura.user', 't');
      trace_context := current_setting('hasura.tracecontext', 't');
    ELSE
      BEGIN
        session_variables := current_setting('hasura.user');
      EXCEPTION WHEN OTHERS THEN
                  session_variables := NULL;
      END;
      BEGIN
        trace_context := current_setting('hasura.tracecontext');
      EXCEPTION WHEN OTHERS THEN
        trace_context := NULL;
      END;
    END IF;
    payload := json_build_object(
      'op', op,
      'data', row_data,
      'session_variables', session_variables,
      'trace_context', trace_context
    );
    INSERT INTO hdb_catalog.event_log
                (id, schema_name, table_name, trigger_name, payload)
    VALUES
    (id, schema_name, table_name, trigger_name, payload);
    RETURN id;
  END;
$$ LANGUAGE plpgsql;