Class: ActiveRecord::Materialized::DeltaMaintainer

Inherits:
Object
  • Object
show all
Defined in:
lib/activerecord/materialized/delta_maintainer.rb

Overview

Applies a SummaryDelta to a delta-maintainable view's cache table without re-reading base rows: new partitions inserted, existing ones incremented in place (NULL-safe for SUM), and emptied partitions deleted.

Instance Method Summary collapse

Constructor Details

#initialize(view_class) ⇒ DeltaMaintainer

Returns a new instance of DeltaMaintainer.



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# File 'lib/activerecord/materialized/delta_maintainer.rb', line 9

def initialize(view_class)
  @view_class = view_class
  @analysis = AggregateAnalysis.new(view_class.resolved_source)
end

Instance Method Details

#apply!(summary) ⇒ Object 



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# File 'lib/activerecord/materialized/delta_maintainer.rb', line 14

def apply!(summary)
  summary.buckets.each { |key_tuple, column_deltas| apply_partition(key_tuple, column_deltas) }
  summary.buckets.size # partitions applied; row-count reporting is the caller's job, outside the lock
end