Hi, I wonder if we can collect some stats to measure how effective the prefetching actually is. Ultimately we want something like cache hit ratio, but we're only preloading into page cache, so we can't easily measure that. Perhaps we could measure I/O timings in redo, though?
regards -- Tomas Vondra http://www.2ndQuadrant.comPostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
