Return-Path: Delivered-To: apmail-hadoop-avro-user-archive@minotaur.apache.org Received: (qmail 68405 invoked from network); 17 Aug 2009 19:05:06 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 17 Aug 2009 19:05:06 -0000 Received: (qmail 17776 invoked by uid 500); 17 Aug 2009 19:05:12 -0000 Delivered-To: apmail-hadoop-avro-user-archive@hadoop.apache.org Received: (qmail 17724 invoked by uid 500); 17 Aug 2009 19:05:12 -0000 Mailing-List: contact avro-user-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: avro-user@hadoop.apache.org Delivered-To: mailing list avro-user@hadoop.apache.org Received: (qmail 17715 invoked by uid 99); 17 Aug 2009 19:05:12 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 17 Aug 2009 19:05:12 +0000 X-ASF-Spam-Status: No, hits=0.0 required=10.0 tests= X-Spam-Check-By: apache.org Received: from [140.211.11.9] (HELO minotaur.apache.org) (140.211.11.9) by apache.org (qpsmtpd/0.29) with SMTP; Mon, 17 Aug 2009 19:05:09 +0000 Received: (qmail 68301 invoked by uid 99); 17 Aug 2009 19:04:43 -0000 Received: from localhost.apache.org (HELO [192.168.168.109]) (127.0.0.1) (smtp-auth username cutting, mechanism plain) by minotaur.apache.org (qpsmtpd/0.29) with ESMTP; Mon, 17 Aug 2009 19:04:43 +0000 Message-ID: <4A89A9D0.1020202@apache.org> Date: Mon, 17 Aug 2009 12:04:48 -0700 From: Doug Cutting User-Agent: Thunderbird 2.0.0.22 (X11/20090608) MIME-Version: 1.0 To: avro-user@hadoop.apache.org Subject: Re: mixing types using reflection References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Checked: Checked by ClamAV on apache.org Eelco Hillenius wrote: > There are two show stoppers for me right now, AVRO-93 and AVRO-95. > Now, my question is about the latter one, which is about mixing > multiple types in one data file using reflection. I submitted a unit > test for it that shows the bug, but I'm wondering if the way I'm using > the API is as it is intended. No, it is not. An Avro data file is expected to contain instances that all conform to a single schema. If you have multiple classes that you'd like to store in a single file then you can use a union schema, e.g.: List records = new ArrayList(); records.add(ReflectData.getSchema(MyRecord1.class)); records.add(ReflectData.getSchema(MyRecord2.class)); records.add(ReflectData.getSchema(MyRecord3.class)); Schema union = Schema.createUnion(records); DataFileWriter