On 10/29/21 08:49, Peter J. Holzer wrote:
I don't think that's equivalent. An Oracle instance is a runtime concept
(the collection of server processes on a single machine serving a single
database (the collection of files on the disk)) whereas a PostgreSQL cluster is
both a data and a runtime concept (config + data files for several
databases with some shared data + the processes serving them). Also
instance:database is n:1 while cluster to database is 1:n. Very
different.
Peter, Oracle instance manages collection of the databases and is
ensuring recoverabilty using redo logs, which are completely analogous
to WAL logs, if managed a bit differently. Let's not be nitpicking here.
Oracle instance is completely analogous to Postgres cluster. If you ask
me, the word cluster was picked to avoid the word "instance"
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Mladen Gogala
Database Consultant
Tel: (347) 321-1217
https://dbwhisperer.wordpress.com
