On Wed, 2008-08-13 at 15:38 +0200, Markus Wanner wrote: > Simon Riggs wrote: > > Classification of Replication Techniques > > Thanks for your classifications. It helps a great deal to clarify. > > > Type 2 is where you ship the WAL (efficient) then use it to reconstruct > > SQL (flexible) and then apply that to other nodes. It is somewhat harder > > than type 1, but requires less infrastructure (IMHO). Definitely > > requires less data shipping from Primary node, so very possibly more > > efficient. > > What leads you to that conclusion? AFAICT a logical format, specifically > designed for replication is quite certainly more compact than the WAL > (assuming that's what you mean by "less data").
Possibly, but since we are generating and writing WAL anyway that's not a completely fair comparison. > Which of IBM's and Oracle's products are you referring to? IBM DB2 HADR, QReplication. Oracle Streams 10g+, Data Guard Logical and Physical Standby All of which I've personally used, except for Oracle Streams10g, which I investigated thoroughly for a client about 4 years ago. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
