以节省内存和性能的方式在表中查找记录和种子

发布于 2024-11-08 11:14:05 字数 529 浏览 0 评论 0原文

我正在 Rails 2.3.11 环境中工作。

我想像这样创建一个 Social_activities 表：

votes = Vote.find(:all, :limit => 10000, :order => 'created_at DESC')
for vote in votes do
  act = vote.activity_for!
  act.created_at = vote.created_at
  act.save!
end

comments = Comment.find(:all, :limit => 10000, :order => 'created_at DESC')
for comment in comments do
  act = comment.activity_for!
  act.created_at = comment.created_at
  act.save!
end

...等等...

如您所见，我正在处理很多记录。我怎样才能以最节省内存和性能的方式做到这一点？

原文

I'm working in Rails 2.3.11 environment.

I want to seed a social_activities table like so:

votes = Vote.find(:all, :limit => 10000, :order => 'created_at DESC')
for vote in votes do
  act = vote.activity_for!
  act.created_at = vote.created_at
  act.save!
end

comments = Comment.find(:all, :limit => 10000, :order => 'created_at DESC')
for comment in comments do
  act = comment.activity_for!
  act.created_at = comment.created_at
  act.save!
end

...and...so on...

As you can see, I'm processing a lot of records. How can I do so in the most memory- and performance-efficient way?

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花开柳相依 2024-11-15 11:14:05

您可以通过减小此数字（例如 100）并使用 find_each 遍历所有记录来减少内存中的对象数量，而不是一次获取 10000 条记录。

Vote.find_each(:order => 'created_at DESC', :batch_size => 100) do |vote|
  act = vote.activity_for!
  act.created_at = vote.created_at
  act.save!
end

Comment.find_each(:order => 'created_at DESC', :batch_size => 100) do |comment|
  act = comment.activity_for!
  act.created_at = comment.created_at
  act.save!
end

现在一次仅获取 100 条记录，从而减少了内存占用。

Instead of fetching 10000 records at a time, you can reduce the number of objects in memory by making this number smaller (say 100), and using find_each to work your way through all the records.

Vote.find_each(:order => 'created_at DESC', :batch_size => 100) do |vote|
  act = vote.activity_for!
  act.created_at = vote.created_at
  act.save!
end

Comment.find_each(:order => 'created_at DESC', :batch_size => 100) do |comment|
  act = comment.activity_for!
  act.created_at = comment.created_at
  act.save!
end

Now records will only be fetched 100 at a time, reducing the memory footprint.

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