Thanks to Jim for replying us about WAL archiving! Indeed, WAL archiving has been abandoned for our needs. The content logged in WAL is more than only the modified data but the binary content of the modified table (or a part of the table). Then it is not possible to merge modifications on a common table from different databases. Because replication system implies to increase database size, we decided to serialize the write database traffic in our code. Then we deserialize the traffic logs on the multisite database in a nightly cron. We suppose that the time to serialize/deserialize is not so important than the content exanged and the size of databases. Hugues -----Message d'origine----- De : Jim C. Nasby [mailto:jnasby@xxxxxxxxxxxxx] Envoyé : mardi 16 mai 2006 00:04 À : Houssais Hugues Cc : pgsql-general@xxxxxxxxxxxxxx Objet : Re: [GENERAL] Concatenate WAL contents On Wed, May 10, 2006 at 11:55:49AM +0200, Houssais Hugues wrote: > Hi, > > In order to unify many distant Postgres databases, we decided to use WAL > archiving. The idea is to concatenate a distant WAL archive at the > beginning of a local WAL archive before launching PITR restore. > > Does anyone know how to concatenate WAL contents, i.e. decode and encode > WAL files using the address of backup files (aaa in xxxxx.aaa.backup > files)? It's not possible to do multi-master WAL-based replication, because it describes table changes at a binary level. -- Jim C. Nasby, Sr. Engineering Consultant jnasby@xxxxxxxxxxxxx Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
