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From: Markus Wanner on 13 Jul 2010 10:31 Finally, this patch adds the capability to cache out-of-order messages for workers within the coordinator process. Unlike the cache of jobs, which basically are messages as well, these messages don't trigger a job, but might provide additional information or data payload to a worker that's already processing a job. In case of Postgres-R, the very first change set received starts an applicator job, while every subsequent change set as well as the final commit decision are such ooo-messages, which are forwarded to the same worker. A parallel querying feature might want to use similar ooo messages for data payload, forth and back. However, simpler jobs like vacuum don't necessarily need this. |