@Override
    public ResultSet readTable(String tableName, String[] columns, int nThread)
            throws SQLException {
//        if (columns == null) {
//            columns = getColumnNames(tableName);
//        }

        //        boolean first = true;
//        for (String col : columns) {
//            if (!first) {
//                sb.append(", ");
//            }
//            sb.append(escapeColName(col));
//            first = false;
//        }

        if (tableName == null) tableName = this.options.getSourceTable();

        String allColumns;

        if (this.options.getSourceColumns() == null) allColumns = "*";
        else {
            allColumns = this.options.getSourceColumns();
        }


        String sqlCmd = "SELECT " +
                allColumns +
                " FROM " +
                escapeTableName(tableName);
                /*" AS " +   // needed for hsqldb; doesn't hurt anyone else.
                // Oracle Hurt...
                escapeTableName(tableName);*/
        LOG.debug(Thread.currentThread().getName() + ": Reading table with command: " + sqlCmd);
        return execute(sqlCmd);
    }
Sets default values for values that were not provided by the user.
Only options with database-specific defaults should be configured here.
src/main/java/org/replicadb/manager/SqlManager.java