class NoSE::Cost::CassandraCost
A cost model which estimates the number of requests to the backend
Public Instance Methods
delete_cost(step)
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Cost
estimate as number of entities deleted
# File lib/nose/cost/cassandra.rb, line 21 def delete_cost(step) return nil if step.state.nil? step.state.cardinality * @options[:delete_cost] end
index_lookup_cost(step)
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Rough cost estimate as the number of requests made @return [Numeric]
# File lib/nose/cost/cassandra.rb, line 11 def index_lookup_cost(step) return nil if step.state.nil? rows = step.state.cardinality parts = step.state.hash_cardinality @options[:index_cost] + parts * @options[:partition_cost] + rows * @options[:row_cost] end
insert_cost(step)
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Cost
estimate as number of entities inserted
# File lib/nose/cost/cassandra.rb, line 27 def insert_cost(step) return nil if step.state.nil? step.state.cardinality * @options[:insert_cost] end