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157f6a6efe
Before IN clause optimization70ddb8a, Active Record had generated an SQL with binds when `prepared_statements: true`: ```ruby # prepared_statements: true # # SELECT `authors`.* FROM `authors` WHERE `authors`.`id` IN (?, ?, ?) # # prepared_statements: false # # SELECT `authors`.* FROM `authors` WHERE `authors`.`id` IN (1, 2, 3) # Author.where(id: [1, 2, 3]).to_a ``` But now, binds in IN clause is substituted regardless of whether `prepared_statements: true` or not: ```ruby # prepared_statements: true # # SELECT `authors`.* FROM `authors` WHERE `authors`.`id`IN (1,2,3) # # prepared_statements: false # # SELECT `authors`.* FROM `authors` WHERE `authors`.`id`IN (1,2,3) # Author.where(id: [1, 2, 3]).to_a ``` I suppose that is considered as a regression for the context: > While I would prefer that we fix/avoid the too-many-parameters problem, but I don't like the idea of globally ditching bind params for this edge case... we're getting to the point where I'd almost consider anything that doesn't use a bind to be a bug. https://github.com/rails/rails/pull/33844#issuecomment-421000003 This makes binds consider whether `prepared_statements: true` or not (i.e. restore the original behavior as before), but still gain that optimization when need the substitute binds (`prepared_statements: false`, `relation.to_sql`). Even when `prepared_statements: true`, it still much faster than before by optimized (bind node less) binds generation. ```ruby class Post < ActiveRecord::Base end ids = (1..1000).each.map do |n| Post.create!.id end puts "prepared_statements: #{Post.connection.prepared_statements.inspect}" Benchmark.ips do |x| x.report("where with ids") do Post.where(id: ids).to_a end end ``` * Before (200058b011) `prepared_statements: true`: ``` Warming up -------------------------------------- where with ids 6.000 i/100ms Calculating ------------------------------------- where with ids 63.806 (± 7.8%) i/s - 318.000 in 5.015903s ``` `prepared_statements: false`: ``` Warming up -------------------------------------- where with ids 7.000 i/100ms Calculating ------------------------------------- where with ids 73.550 (± 8.2%) i/s - 371.000 in 5.085672s ``` * Now with this change `prepared_statements: true`: ``` Warming up -------------------------------------- where with ids 9.000 i/100ms Calculating ------------------------------------- where with ids 91.992 (± 7.6%) i/s - 459.000 in 5.020817s ``` `prepared_statements: false`: ``` Warming up -------------------------------------- where with ids 10.000 i/100ms Calculating ------------------------------------- where with ids 104.335 (± 8.6%) i/s - 520.000 in 5.026425s ```
54 lines
1.4 KiB
Ruby
54 lines
1.4 KiB
Ruby
# frozen_string_literal: true
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require "active_record/explain_registry"
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module ActiveRecord
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module Explain
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# Executes the block with the collect flag enabled. Queries are collected
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# asynchronously by the subscriber and returned.
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def collecting_queries_for_explain # :nodoc:
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ExplainRegistry.collect = true
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yield
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ExplainRegistry.queries
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ensure
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ExplainRegistry.reset
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end
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# Makes the adapter execute EXPLAIN for the tuples of queries and bindings.
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# Returns a formatted string ready to be logged.
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def exec_explain(queries) # :nodoc:
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str = queries.map do |sql, binds|
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msg = +"EXPLAIN for: #{sql}"
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unless binds.empty?
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msg << " "
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msg << binds.map { |attr| render_bind(attr) }.inspect
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end
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msg << "\n"
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msg << connection.explain(sql, binds)
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end.join("\n")
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# Overriding inspect to be more human readable, especially in the console.
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def str.inspect
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self
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end
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str
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end
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private
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def render_bind(attr)
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if ActiveModel::Attribute === attr
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value = if attr.type.binary? && attr.value
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"<#{attr.value_for_database.to_s.bytesize} bytes of binary data>"
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else
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connection.type_cast(attr.value_for_database)
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end
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else
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value = connection.type_cast(attr)
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attr = nil
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end
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[attr&.name, value]
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end
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end
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end
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