Backport explain fixes.

* Mark as SCHEMA some schema database queries. #7648
* Don't explain queries except normal CRUD sql. #7657

Closes #6458
Closes #7544

3 files changed, 13 insertions, 12 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index a22ccfab86..5108f4113f 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -817,7 +817,7 @@ module ActiveRecord
 
       # Returns an array of indexes for the given table.
       def indexes(table_name, name = nil)
-         result = query(<<-SQL, name)
+         result = query(<<-SQL, 'SCHEMA')
            SELECT distinct i.relname, d.indisunique, d.indkey, pg_get_indexdef(d.indexrelid), t.oid
            FROM pg_class t
            INNER JOIN pg_index d ON t.oid = d.indrelid
@@ -837,7 +837,7 @@ module ActiveRecord
           inddef = row[3]
           oid = row[4]
 
-          columns = Hash[query(<<-SQL, "Columns for index #{row[0]} on #{table_name}")]
+          columns = Hash[query(<<-SQL, "SCHEMA")]
           SELECT a.attnum, a.attname
           FROM pg_attribute a
           WHERE a.attrelid = #{oid}
@@ -849,7 +849,7 @@ module ActiveRecord
           # add info on sort order for columns (only desc order is explicitly specified, asc is the default)
           desc_order_columns = inddef.scan(/(\w+) DESC/).flatten
           orders = desc_order_columns.any? ? Hash[desc_order_columns.map {|order_column| [order_column, :desc]}] : {}
-      
+
           column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names, [], orders)
         end.compact
       end
@@ -864,7 +864,7 @@ module ActiveRecord
 
       # Returns the current database name.
       def current_database
-        query('select current_database()')[0][0]
+        query('select current_database()', 'SCHEMA')[0][0]
       end
 
       # Returns the current schema name.
@@ -874,7 +874,7 @@ module ActiveRecord
 
       # Returns the current database encoding format.
       def encoding
-        query(<<-end_sql)[0][0]
+        query(<<-end_sql, 'SCHEMA')[0][0]
           SELECT pg_encoding_to_char(pg_database.encoding) FROM pg_database
           WHERE pg_database.datname LIKE '#{current_database}'
         end_sql
@@ -937,7 +937,7 @@ module ActiveRecord
         if pk && sequence
           quoted_sequence = quote_table_name(sequence)
 
-          select_value <<-end_sql, 'Reset sequence'
+          select_value <<-end_sql, 'SCHEMA'
             SELECT setval('#{quoted_sequence}', (SELECT COALESCE(MAX(#{quote_column_name pk})+(SELECT increment_by FROM #{quoted_sequence}), (SELECT min_value FROM #{quoted_sequence})) FROM #{quote_table_name(table)}), false)
           end_sql
         end
@@ -947,7 +947,7 @@ module ActiveRecord
       def pk_and_sequence_for(table) #:nodoc:
         # First try looking for a sequence with a dependency on the
         # given table's primary key.
-        result = query(<<-end_sql, 'PK and serial sequence')[0]
+        result = query(<<-end_sql, 'SCHEMA')[0]
           SELECT attr.attname, seq.relname
           FROM pg_class      seq,
                pg_attribute  attr,
@@ -968,7 +968,7 @@ module ActiveRecord
           # If that fails, try parsing the primary key's default value.
           # Support the 7.x and 8.0 nextval('foo'::text) as well as
           # the 8.1+ nextval('foo'::regclass).
-          result = query(<<-end_sql, 'PK and custom sequence')[0]
+          result = query(<<-end_sql, 'SCHEMA')[0]
             SELECT attr.attname,
               CASE
                 WHEN split_part(def.adsrc, '''', 2) ~ '.' THEN
@@ -1086,7 +1086,7 @@ module ActiveRecord
           end
         when 'integer'
           return 'integer' unless limit
-  
+
           case limit
             when 1, 2; 'smallint'
             when 3, 4; 'integer'
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
index 00f74318c0..731f7e2049 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb
@@ -359,12 +359,12 @@ module ActiveRecord
 
       # Returns an array of indexes for the given table.
       def indexes(table_name, name = nil) #:nodoc:
-        exec_query("PRAGMA index_list(#{quote_table_name(table_name)})", name).map do |row|
+        exec_query("PRAGMA index_list(#{quote_table_name(table_name)})", 'SCHEMA').map do |row|
           IndexDefinition.new(
             table_name,
             row['name'],
             row['unique'] != 0,
-            exec_query("PRAGMA index_info('#{row['name']}')").map { |col|
+            exec_query("PRAGMA index_info('#{row['name']}')", 'SCHEMA').map { |col|
               col['name']
             })
         end
diff --git a/activerecord/lib/active_record/explain_subscriber.rb b/activerecord/lib/active_record/explain_subscriber.rb
index 1f8c4fc203..859c8edfc5 100644
--- a/activerecord/lib/active_record/explain_subscriber.rb
+++ b/activerecord/lib/active_record/explain_subscriber.rb
@@ -15,8 +15,9 @@ module ActiveRecord
     # On the other hand, we want to monitor the performance of our real database
     # queries, not the performance of the access to the query cache.
     IGNORED_PAYLOADS = %w(SCHEMA EXPLAIN CACHE)
+    EXPLAINED_SQLS = /\A\s*(select|update|delete|insert)/i
     def ignore_payload?(payload)
-      payload[:exception] || IGNORED_PAYLOADS.include?(payload[:name])
+      payload[:exception] || IGNORED_PAYLOADS.include?(payload[:name]) || payload[:sql] !~ EXPLAINED_SQLS
     end
 
     ActiveSupport::Notifications.subscribe("sql.active_record", new)