Re: Oracle vs Informix comparison

In article <589udr$mgk@svna0001.clipper.ssb.com>, Stephen A Tahmosh <tahmossx@itd.ssb.com> writes >Why is replication off of the logs automatically better than that provided via >stored procedures and triggers? >All data (almost) is logged - not all data is replicated (usually). >Triggers/Stored Procedures can be defined only on objects which need >replication. > With stored procedures replication happens as follows. Application updates one table. Triggers fires Procedure fires Procdures sends update to remote site Remote site performs update Remote site replys update ok. ... Application commits. Commit send to remote site (2 phase commit protocal followed). Application continues. I.e. 6 steps per table update (including 2 x network messages). several steps for the commit (2phase commit). + transaction logging. With logical log replication the 6 steps per update do not happen and neither does to two phase commit. Instead the transaction logging is sent across the network. This can contain the whole transaction in less network messages (since >1 update can be put in one message). Also the application can update and data replication replicate but they do not have to happen in sync. Only when a commit/checkpoint occurs do they have to sync. -- David Williams