Methods
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Attributes
[R] query_cache
[R] query_cache_enabled
Class Public methods
new(*)
# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 23
def initialize(*)
  super
  @query_cache         = Hash.new { |h,sql| h[sql] = {} }
  @query_cache_enabled = false
end
Instance Public methods
cache()

Enable the query cache within the block.

# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 30
def cache
  old, @query_cache_enabled = @query_cache_enabled, true
  yield
ensure
  @query_cache_enabled = old
  clear_query_cache unless @query_cache_enabled
end
clear_query_cache()

Clears the query cache.

One reason you may wish to call this method explicitly is between queries that ask the database to randomize results. Otherwise the cache would see the same SQL query and repeatedly return the same result each time, silently undermining the randomness you were expecting.

# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 60
def clear_query_cache
  @query_cache.clear
end
dirties_query_cache(base, *method_names)
# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 9
        def dirties_query_cache(base, *method_names)
          method_names.each do |method_name|
            base.class_eval "              def #{method_name}(*)
                clear_query_cache if @query_cache_enabled
                super
              end
", __FILE__, __LINE__ + 1
          end
        end
disable_query_cache!()
# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 42
def disable_query_cache!
  @query_cache_enabled = false
end
enable_query_cache!()
# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 38
def enable_query_cache!
  @query_cache_enabled = true
end
select_all(arel, name = nil, binds = [])
# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 64
def select_all(arel, name = nil, binds = [])
  if @query_cache_enabled && !locked?(arel)
    arel, binds = binds_from_relation arel, binds
    sql = to_sql(arel, binds)
    cache_sql(sql, binds) { super(sql, name, binds) }
  else
    super
  end
end
uncached()

Disable the query cache within the block.

# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 47
def uncached
  old, @query_cache_enabled = @query_cache_enabled, false
  yield
ensure
  @query_cache_enabled = old
end