Module: ActiveRecord::Relation::RecordFetchWarning

Defined in:
activerecord/lib/active_record/relation/record_fetch_warning.rb

Defined Under Namespace

Modules: QueryRegistry

Instance Method Summary collapse

Instance Method Details

#exec_queriesObject

When this module is prepended to ActiveRecord::Relation and config.active_record.warn_on_records_fetched_greater_than is set to an integer, if the number of records a query returns is greater than the value of warn_on_records_fetched_greater_than, a warning is logged. This allows for the detection of queries that return a large number of records, which could cause memory bloat.

In most cases, fetching large number of records can be performed efficiently using the ActiveRecord::Batches methods. See ActiveRecord::Batches for more information.


16
17
18
19
20
21
22
23
24
25
26
# File 'activerecord/lib/active_record/relation/record_fetch_warning.rb', line 16

def exec_queries
  QueryRegistry.reset

  super.tap do |records|
    if logger && ActiveRecord.warn_on_records_fetched_greater_than
      if records.length > ActiveRecord.warn_on_records_fetched_greater_than
        logger.warn "Query fetched #{records.size} #{@klass} records: #{QueryRegistry.queries.join(";")}"
      end
    end
  end
end