diff options
Diffstat (limited to 'activerecord/lib')
3 files changed, 47 insertions, 14 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb b/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb index 295a7bed87..447c809e85 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb @@ -182,7 +182,10 @@ module ActiveRecord transaction = begin_transaction options yield rescue Exception => error - rollback_transaction if transaction + if transaction + rollback_transaction + after_failure_actions(transaction, error) + end raise ensure unless error @@ -208,7 +211,16 @@ module ActiveRecord end private + NULL_TRANSACTION = NullTransaction.new + + # Deallocate invalidated prepared statements outside of the transaction + def after_failure_actions(transaction, error) + return unless transaction.is_a?(RealTransaction) + return unless error.is_a?(ActiveRecord::PreparedStatementCacheExpired) + @connection.clear_cache! + end + end end end diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb index ed6ab8235f..7ab35cfb76 100644 --- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb @@ -589,25 +589,41 @@ module ActiveRecord @connection.exec_prepared(stmt_key, type_casted_binds) end rescue ActiveRecord::StatementInvalid => e - pgerror = e.cause + raise unless is_cached_plan_failure?(e) - # Get the PG code for the failure. Annoyingly, the code for - # prepared statements whose return value may have changed is - # FEATURE_NOT_SUPPORTED. Check here for more details: - # http://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/utils/cache/plancache.c#l573 - begin - code = pgerror.result.result_error_field(PGresult::PG_DIAG_SQLSTATE) - rescue - raise e - end - if FEATURE_NOT_SUPPORTED == code + # Nothing we can do if we are in a transaction because all commands + # will raise InFailedSQLTransaction + if in_transaction? + raise ActiveRecord::PreparedStatementCacheExpired.new(e.cause.message) + else + # outside of transactions we can simply flush this query and retry @statements.delete sql_key(sql) retry - else - raise e end end + # Annoyingly, the code for prepared statements whose return value may + # have changed is FEATURE_NOT_SUPPORTED. + # + # This covers various different error types so we need to do additional + # work to classify the exception definitively as a + # ActiveRecord::PreparedStatementCacheExpired + # + # Check here for more details: + # http://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/utils/cache/plancache.c#l573 + CACHED_PLAN_HEURISTIC = 'cached plan must not change result type'.freeze + def is_cached_plan_failure?(e) + pgerror = e.cause + code = pgerror.result.result_error_field(PGresult::PG_DIAG_SQLSTATE) + code == FEATURE_NOT_SUPPORTED && pgerror.message.include?(CACHED_PLAN_HEURISTIC) + rescue + false + end + + def in_transaction? + open_transactions > 0 + end + # Returns the statement identifier for the client side cache # of statements def sql_key(sql) diff --git a/activerecord/lib/active_record/errors.rb b/activerecord/lib/active_record/errors.rb index 1cd2c2ef8c..ee7df61715 100644 --- a/activerecord/lib/active_record/errors.rb +++ b/activerecord/lib/active_record/errors.rb @@ -139,6 +139,11 @@ module ActiveRecord class NoDatabaseError < StatementInvalid end + # Raised when Postgres returns 'cached plan must not change result type' and + # we cannot retry gracefully (e.g. inside a transaction) + class PreparedStatementCacheExpired < StatementInvalid + end + # Raised on attempt to save stale record. Record is stale when it's being saved in another query after # instantiation, for example, when two users edit the same wiki page and one starts editing and saves # the page before the other. |