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| author | Ryuta Kamizono <kamipo@gmail.com> | 2019-03-13 09:29:00 +0900 |
|---|---|---|
| committer | Ryuta Kamizono <kamipo@gmail.com> | 2019-03-16 18:44:55 +0900 |
| commit | 97347d8c409f14b682dd9ec52ded3c869d0ba479 (patch) | |
| tree | 7baf7114da2ed0e305663085778267b6a3f06cb7 /activerecord/lib/arel/nodes | |
| parent | 85984e50311b7138504abe1be9bbe99f96dde8ef (diff) | |
| download | rails-97347d8c409f14b682dd9ec52ded3c869d0ba479.tar.gz rails-97347d8c409f14b682dd9ec52ded3c869d0ba479.tar.bz2 rails-97347d8c409f14b682dd9ec52ded3c869d0ba479.zip | |
Support Optimizer Hints
We as Arm Treasure Data are using Optimizer Hints with a monkey patch
(https://gist.github.com/kamipo/4c8539f0ce4acf85075cf5a6b0d9712e),
especially in order to use `MAX_EXECUTION_TIME` (refer #31129).
Example:
```ruby
class Job < ApplicationRecord
default_scope { optimizer_hints("MAX_EXECUTION_TIME(50000) NO_INDEX_MERGE(jobs)") }
end
```
Optimizer Hints is supported not only for MySQL but also for most
databases (PostgreSQL on RDS, Oracle, SQL Server, etc), it is really
helpful to turn heavy queries for large scale applications.
Diffstat (limited to 'activerecord/lib/arel/nodes')
| -rw-r--r-- | activerecord/lib/arel/nodes/select_core.rb | 5 | ||||
| -rw-r--r-- | activerecord/lib/arel/nodes/unary.rb | 1 |
2 files changed, 4 insertions, 2 deletions
diff --git a/activerecord/lib/arel/nodes/select_core.rb b/activerecord/lib/arel/nodes/select_core.rb index 73461ff683..5814cae98a 100644 --- a/activerecord/lib/arel/nodes/select_core.rb +++ b/activerecord/lib/arel/nodes/select_core.rb @@ -4,7 +4,7 @@ module Arel # :nodoc: all module Nodes class SelectCore < Arel::Nodes::Node attr_accessor :projections, :wheres, :groups, :windows - attr_accessor :havings, :source, :set_quantifier + attr_accessor :havings, :source, :set_quantifier, :optimizer_hints def initialize super() @@ -42,7 +42,7 @@ module Arel # :nodoc: all def hash [ - @source, @set_quantifier, @projections, + @source, @set_quantifier, @projections, @optimizer_hints, @wheres, @groups, @havings, @windows ].hash end @@ -51,6 +51,7 @@ module Arel # :nodoc: all self.class == other.class && self.source == other.source && self.set_quantifier == other.set_quantifier && + self.optimizer_hints == other.optimizer_hints && self.projections == other.projections && self.wheres == other.wheres && self.groups == other.groups && diff --git a/activerecord/lib/arel/nodes/unary.rb b/activerecord/lib/arel/nodes/unary.rb index 00639304e4..6d1ac36b0e 100644 --- a/activerecord/lib/arel/nodes/unary.rb +++ b/activerecord/lib/arel/nodes/unary.rb @@ -35,6 +35,7 @@ module Arel # :nodoc: all Not Offset On + OptimizerHints Ordering RollUp }.each do |name| |