For Postgres just run the create_tables.sql

For MySQL with autoincrement remove the sequence creation in create_tables.sql and run it ;)

REMOVE THIS LINES from create_tables.sql

// SEQ Postgres
CREATE SEQUENCE leg.seq_msg_id
  INCREMENT 1
  MINVALUE 1
  MAXVALUE 100000000
  START 1
  CACHE 1;

CREATE SEQUENCE leg.seq_thread_id
  INCREMENT 1
  MINVALUE 1
  MAXVALUE 100000000
  START 1
  CACHE 1;

Do changes in MSGBox.php

Adjust these lines:

private static $SEQ_MSG_ID = "leg.seq_msg_id"; // null for MySQL
private static $SEQ_THREAD_ID = "leg.seq_thread_id"; // null for MySQL
private static $IDENTIFIER = '"'; // "" for MySQL
private static $SCHEMA = 'leg';