From 61241833ec54fbb030da490eecc5bc69f44dc86e Mon Sep 17 00:00:00 2001
From: Ryuta Kamizono <kamipo@gmail.com>
Date: Fri, 10 Feb 2017 10:52:25 +0900
Subject: Revert "Simplify and speed up Postgres query for primary_keys"
This reverts commit d6529af2954a67bd57fda45286fa9cfd0ff6b5ac.
---
.../postgresql/schema_statements.rb | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
(limited to 'activerecord/lib')
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index bd8aab526e..a4b1723fc7 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -426,14 +426,16 @@ module ActiveRecord
def primary_keys(table_name) # :nodoc:
select_values(<<-SQL.strip_heredoc, "SCHEMA")
- SELECT a.attname
- FROM pg_index i
- CROSS JOIN unnest(i.indkey) as k
- JOIN pg_attribute a
- ON a.attrelid = i.indrelid
- AND a.attnum = k
- WHERE i.indrelid = #{quote(quote_table_name(table_name))}::regclass
- AND i.indisprimary
+ WITH pk_constraint AS (
+ SELECT conrelid, unnest(conkey) AS connum FROM pg_constraint
+ WHERE contype = 'p'
+ AND conrelid = #{quote(quote_table_name(table_name))}::regclass
+ ), cons AS (
+ SELECT conrelid, connum, row_number() OVER() AS rownum FROM pk_constraint
+ )
+ SELECT attr.attname FROM pg_attribute attr
+ INNER JOIN cons ON attr.attrelid = cons.conrelid AND attr.attnum = cons.connum
+ ORDER BY cons.rownum
SQL
end
--
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