Class: ActiveRecord::Materialized::ViewDefinition Private

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

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

Inspects a source relation for its partition (maintenance) keys and builds partition scopes. The keys are the relation's GROUP BY columns, or — for a SELECT DISTINCT a, b with no GROUP BY and no aggregate — its projected columns, since a distinct lookup partitions exactly like a GROUP BY of those columns.

Instance Method Summary collapse

Constructor Details

#initialize(source, explicit_group_keys: nil) ⇒ ViewDefinition

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of ViewDefinition.



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# File 'lib/activerecord/materialized/view_definition.rb', line 12

def initialize(source, explicit_group_keys: nil)
  @source = source
  @explicit_group_keys = explicit_group_keys
end

Instance Method Details

#group_key_columns ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/activerecord/materialized/view_definition.rb', line 21

def group_key_columns
  @group_key_columns ||= resolve_group_key_columns
end

#incrementally_maintainable? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns:

  • (Boolean) 


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# File 'lib/activerecord/materialized/view_definition.rb', line 17

def incrementally_maintainable?
  group_key_columns.any?
end

#partition_scope(key_tuples) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Restrict the source relation to the given partitions. Qualify each key to its GROUP BY attribute's own table, which may be a joined table (e.g. name.gender) rather than the source's base table.



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# File 'lib/activerecord/materialized/view_definition.rb', line 38

def partition_scope(key_tuples)
  validate_partition_keys!(key_tuples)
  base = source.klass.arel_table
  attributes = group_key_columns.map { |column| source_attribute(column, base) }
  PartitionFilter.new(attributes, key_tuples).apply(source)
end

#partition_scope_on(model, key_tuples) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Restrict a model/cache table to the given partitions. The partition columns are real columns on model, so qualify them to its own table.



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# File 'lib/activerecord/materialized/view_definition.rb', line 27

def partition_scope_on(model, key_tuples)
  validate_partition_keys!(key_tuples)
  # On the cache/model table the key is the projected column, so a qualified
  # GROUP BY name (e.g. "authors.country") maps to the bare column ("country").
  attributes = group_key_columns.map { |column| model.arel_table[unqualified(column)] }
  PartitionFilter.new(attributes, key_tuples).apply(model.unscoped)
end