Rails：迁移后的奇怪查询

Question

已经有一段时间了，但我现在只照顾这个。

在Rails 3.2中，每次运行迁移（rake db:migrate）时，在执行迁移的正常SQL日志之后，我都会遇到一堆非常混乱的查询。

他们是：

   (0.8ms)  INSERT INTO "schema_migrations" ("version") VALUES ('20150623124632')
   (5.6ms)  COMMIT
   (1.2ms)  SELECT "schema_migrations"."version" FROM "schema_migrations" 
   (5.9ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'addresses'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (4.2ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'authentications'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.3ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'balancing_transactions'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.6ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'billing_informations'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.4ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'bills'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.1ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'checkins'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.2ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'converters'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.2ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'copass_transactions'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.2ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'copasser_preferences'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.2ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'copassers'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.2ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'cospace_comments'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.0ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'cospace_copasser_interactions'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.1ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'cospace_event_type_associations'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.2ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'cospace_pictures'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.1ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'cospace_recommends'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.1ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'cospace_tag_votes'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.3ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'cospace_transaction_templates'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.2ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'cospace_type_associations'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.1ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'cospace_wishlists'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.1ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'cospaces'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.2ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'countries'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.2ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'coupons'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.4ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'currency_accounts'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (6.9ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'delayed_jobs'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.4ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'event_types'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.2ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'external_transactions'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.3ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'faqs'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.5ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'finances'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.4ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'friend_suggestions'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.2ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'friendship_notifications'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (9.0ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'friendships'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.4ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'group_copassers'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (6.9ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'groups'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.conname

   (5.2ms)  
 SELECT t2.relname AS to_table
 , a1.attname AS column
 , a2.attname AS primary_key
 , c.conname AS name
 , c.confdeltype AS dependency
 , c.confupdtype AS update_dependency
 , c.condeferrable AS deferrable
 , c.condeferred AS deferred
 , c.convalidated AS valid
 FROM pg_constraint c
 JOIN pg_class t1 ON c.conrelid = t1.oid
 JOIN pg_class t2 ON c.confrelid = t2.oid
 JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
 JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
 JOIN pg_namespace t3 ON c.connamespace = t3.oid
 WHERE c.contype = 'f'
 AND t1.relname = 'in_progress_transactions'
 AND t3.nspname = ANY (current_schemas(false))
 ORDER BY c.

# [TRUNKED BECAUSE OF Stackoverflow LIMITATION]

它永远不会破坏任何东西，因为那些只是SELECT s，但它们非常难看并且阻止我轻易地检查一切都很顺利。

知道这是从哪里来的吗？

Answer 1

这看起来就像Rails爬行模式以确定模型的结构。 db:migrate通常很安静，因此输出可能是rails_12factor宝石的结果，如果您正在使用它（通常使用Heroku）。如果是这样，您可以使用this question's解决方案并将该gem包装在:production块中，因为它不需要在开发中运行。

group :production do
  gem 'rails_12factor'
end