Database.PostgreSQL.PQTypes.Transaction.Settings

Documentation

data RestartPredicate

Predicate that determines whether the transaction has to be restarted.

Constructors

Exception e => RestartPredicate (e -> Integer -> Bool)

Instances

Show RestartPredicate

Defined in Database.PostgreSQL.PQTypes.Transaction.Settings

Methods

showsPrec :: Int -> RestartPredicate -> ShowS

show :: RestartPredicate -> String

showList :: [RestartPredicate] -> ShowS

data TransactionSettings

Constructors

TransactionSettings

Fields

• tsAutoTransaction :: !Bool

  If set to True, transaction will be automatically started at the beginning of database action and after each commit / rollback. If set to False, no transaction will automatically start in either of above cases.

• tsIsolationLevel :: !IsolationLevel

  Isolation level of all transactions.

• tsRestartPredicate :: !(Maybe RestartPredicate)

  Defines behavior of withTransaction in case exceptions thrown within supplied monadic action are not caught and reach its body. If set to Nothing, exceptions will be propagated as usual. If set to Just f, exceptions will be intercepted and passed to f along with a number that indicates how many times the transaction block already failed. If f returns True, the transaction is restarted. Otherwise the exception is further propagated. This allows for restarting transactions e.g. in case of serialization failure. It is up to the caller to ensure that is it safe to execute supplied monadic action multiple times.

• tsPermissions :: !Permissions

  Permissions of all transactions.

Instances

Show TransactionSettings

Defined in Database.PostgreSQL.PQTypes.Transaction.Settings

Methods

showsPrec :: Int -> TransactionSettings -> ShowS

show :: TransactionSettings -> String

showList :: [TransactionSettings] -> ShowS

Default TransactionSettings

Default transaction settings.

Defined in Database.PostgreSQL.PQTypes.Transaction.Settings

Methods

def :: TransactionSettings

data IsolationLevel

Constructors

DefaultLevel

ReadCommitted

RepeatableRead

Serializable

Instances

Eq IsolationLevel

Defined in Database.PostgreSQL.PQTypes.Transaction.Settings

Methods

(==) :: IsolationLevel -> IsolationLevel -> Bool

(/=) :: IsolationLevel -> IsolationLevel -> Bool

Ord IsolationLevel

Defined in Database.PostgreSQL.PQTypes.Transaction.Settings

Methods

compare :: IsolationLevel -> IsolationLevel -> Ordering

(<) :: IsolationLevel -> IsolationLevel -> Bool

(<=) :: IsolationLevel -> IsolationLevel -> Bool

(>) :: IsolationLevel -> IsolationLevel -> Bool

(>=) :: IsolationLevel -> IsolationLevel -> Bool

max :: IsolationLevel -> IsolationLevel -> IsolationLevel

min :: IsolationLevel -> IsolationLevel -> IsolationLevel

Show IsolationLevel

Defined in Database.PostgreSQL.PQTypes.Transaction.Settings

Methods

showsPrec :: Int -> IsolationLevel -> ShowS

show :: IsolationLevel -> String

showList :: [IsolationLevel] -> ShowS

data Permissions

Constructors

DefaultPermissions

ReadOnly

ReadWrite

Instances

Eq Permissions

Defined in Database.PostgreSQL.PQTypes.Transaction.Settings

Methods

(==) :: Permissions -> Permissions -> Bool

(/=) :: Permissions -> Permissions -> Bool

Ord Permissions

Defined in Database.PostgreSQL.PQTypes.Transaction.Settings

Methods

compare :: Permissions -> Permissions -> Ordering

(<) :: Permissions -> Permissions -> Bool

(<=) :: Permissions -> Permissions -> Bool

(>) :: Permissions -> Permissions -> Bool

(>=) :: Permissions -> Permissions -> Bool

max :: Permissions -> Permissions -> Permissions

min :: Permissions -> Permissions -> Permissions

Show Permissions

Defined in Database.PostgreSQL.PQTypes.Transaction.Settings

Methods

showsPrec :: Int -> Permissions -> ShowS

show :: Permissions -> String

showList :: [Permissions] -> ShowS

def :: Default a => a

The default value for this type.