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Add pids table for reverse lookup against values table for efficient matching of get_by_pid. Optimize ets select for get_by_topic by or'ing downed node comparisons.
| mode: :normal, | ||
| values: :ets.new(:values, [:duplicate_bag]), | ||
| values: :ets.new(:values, [:ordered_set]), | ||
| pids: :ets.new(:pids, [:duplicate_bag]), |
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@chrismccord I know this is an old commit, but do you remember why did you use duplicate bag here instead of just bag which still allows duplicate keys?
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duplicate bag will not check for existing keys on insert. It gave us a 10x speedup when we profiled phoenix pubsub back in 2015 for the 2M connection benchmark
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Phoenix channels*. More info on the original PR:
phoenixframework/phoenix#1311
Insertion time is constant for dup bag, where the insertion grows linearly with the bag size for an ordered set. I just realized you are asking :bag vs :duplicate_bag, not vs :ordered_set. I'm not sure of the differences, if any, for bag vs dup bag inserts in the above context.
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Add pids table for reverse lookup against
values table for efficient matching of
get_by_pid.
Optimize ets select for get_by_topic
by or'ing downed node comparisons.