We added an index for `[account_id, reblog_of_id]`, but we already have a similar index for `reblog_of_id`. Those index will be bigger according to statuses count. For example, `reblog_of_id` index uses 800MB for 10GB statuses table. So this patch swaps indexed columns like `[reblog_of_id, account_id]`, then it will covers both usage with single index. Since those index creation may take a while, I've also disabled previous index creation.
		
			
				
	
	
		
			14 lines
		
	
	
	
		
			419 B
		
	
	
	
		
			Ruby
		
	
	
	
	
	
			
		
		
	
	
			14 lines
		
	
	
	
		
			419 B
		
	
	
	
		
			Ruby
		
	
	
	
	
	
| class RemoveOldReblogIndexOnStatuses < ActiveRecord::Migration[5.1]
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|   disable_ddl_transaction!
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| 
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|   def up
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|     # This index may not exists (see migration 20171122120436)
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|     remove_index :statuses, [:account_id, :reblog_of_id] if index_exists?(:statuses, [:account_id, :reblog_of_id])
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| 
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|     remove_index :statuses, :reblog_of_id
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|   end
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| 
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|   def down
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|     add_index :statuses, :reblog_of_id, algorithm: :concurrently
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|   end
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| end
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