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Optimize import script - vanilla_mysql.rb 

Use WHERE id > last_id instead of OFFSET because OFFSET causes performance issues
This commit is contained in:
Melroy Neil Dsouza 2017-06-19 10:30:55 +05:30 committed by GitHub
parent a23ce56682
commit 420abce549
1 changed files with 15 additions and 12 deletions
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23
script/import_scripts/vanilla_mysql.rb
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@ -52,27 +52,26 @@ class ImportScripts::VanillaSQL < ImportScripts::Base
@user_is_deleted = false
@last_deleted_username = nil
username = nil
@last_user_id = -1
total_count = mysql_query("SELECT count(*) count FROM #{TABLE_PREFIX}User;").first['count']
batches(BATCH_SIZE) do |offset|
results = mysql_query(
"SELECT UserID, Name, Title, Location, About, Email,
DateInserted, DateLastActive, InsertIPAddress, Admin
WHERE id > #{@last_user_id}
FROM #{TABLE_PREFIX}User
ORDER BY UserID ASC
LIMIT #{BATCH_SIZE}
OFFSET #{offset};")
LIMIT #{BATCH_SIZE};")
break if results.size < 1
@last_user_id = results.to_a.last['UserID']
next if all_records_exist? :users, results.map {|u| u['UserID'].to_i}
create_users(results, total: total_count, offset: offset) do |user|
next if user['Email'].blank?
next if user['Name'].blank?
next if @lookup.user_id_from_imported_user_id(user['UserID'])
if user['Name'] == '[Deleted User]'
# EVERY deleted user record in Vanilla has the same username: [Deleted User]
# Save our UserNameSuggester some pain:
@ -199,16 +198,19 @@ class ImportScripts::VanillaSQL < ImportScripts::Base
total_count = mysql_query("SELECT count(*) count FROM #{TABLE_PREFIX}Discussion;").first['count']
@last_topic_id = -1
batches(BATCH_SIZE) do |offset|
discussions = mysql_query(
"SELECT DiscussionID, CategoryID, Name, Body,
DateInserted, InsertUserID
WHERE DiscussionID > #{@last_topic_id}
FROM #{TABLE_PREFIX}Discussion
ORDER BY DiscussionID ASC
LIMIT #{BATCH_SIZE}
OFFSET #{offset};")
LIMIT #{BATCH_SIZE};")
break if discussions.size < 1
@last_topic_id = discussions.to_a.last['DiscussionID']
next if all_records_exist? :posts, discussions.map {|t| "discussion#" + t['DiscussionID'].to_s}
create_posts(discussions, total: total_count, offset: offset) do |discussion|
@ -234,17 +236,18 @@ class ImportScripts::VanillaSQL < ImportScripts::Base
puts "", "importing posts..."
total_count = mysql_query("SELECT count(*) count FROM #{TABLE_PREFIX}Comment;").first['count']
@last_post_id = -1
batches(BATCH_SIZE) do |offset|
comments = mysql_query(
"SELECT CommentID, DiscussionID, Body,
DateInserted, InsertUserID
WHERE CommentID > #{@last_post_id}
FROM #{TABLE_PREFIX}Comment
ORDER BY CommentID ASC
LIMIT #{BATCH_SIZE}
OFFSET #{offset};")
LIMIT #{BATCH_SIZE};")
break if comments.size < 1
@last_post_id = comments.to_a.last['CommentID']
next if all_records_exist? :posts, comments.map {|comment| "comment#" + comment['CommentID'].to_s}
create_posts(comments, total: total_count, offset: offset) do |comment|