I add exponential distribution random generator (and little bit refactoring:) ). I use inverse transform method to create its distribution. It's very simple method that is created by - log (rand()). We can control slope of distribution using threshold parameter. It is same as gaussian threshold.
usage example pgbench --exponential=NUM -S Attached graph is created with exponential threshold = 5. We can see exponential distribution in the graphs. It supports -S, -N options and custom script. So we set "¥setexponential [var] [min] [max] [threshold]" in a transaction pattern file, it appear distribution we want. We have no time to fix its very much... But I think almost part of patch have been completed. Regards, -- Mitsumasa KONDO NTT Open Source Software Center
gaussian_and_exponential_pgbench_v6.patch
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<<attachment: exponential=5.png>>
gnuplot.sh
Description: Bourne shell script
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