will use savepoints. with db.atomic() as txn: perform_operation() with db.atomic() as nested_txn: perform_another_operation() Peewee supports nested transactions through the use of savepoints (for more that you use atomic(). Explicit Savepoints Just as you can explicitly create transactions, you can also explicitly create savepoints using the savepoint() method. Savepoints must occur within a transaction • Manages the underlying database connection. • Executes queries. • Manage transactions and savepoints. • Create and drop tables and indexes. • Introspect the database. commit_select = False Whether

can be used to: • Open and close connections. • Execute queries. • Manage transactions (and savepoints). • Introspect tables, columns, indexes, and constraints. • Model integration Peewee comes with will use savepoints. with db.atomic() as txn: perform_operation() with db.atomic() as nested_txn: perform_another_operation() Peewee supports nested transactions through the use of savepoints (for more that you use atomic(). Explicit Savepoints Just as you can explicitly create transactions, you can also explicitly create savepoints using the savepoint() method. Savepoints must occur within a transaction

can be used to: • Open and close connections. • Execute queries. • Manage transactions (and savepoints). • Introspect tables, columns, indexes, and constraints. • Model integration Peewee comes with will use savepoints. with db.atomic() as txn: perform_operation() with db.atomic() as nested_txn: perform_another_operation() Peewee supports nested transactions through the use of savepoints (for more that you use atomic(). Explicit Savepoints Just as you can explicitly create transactions, you can also explicitly create savepoints using the savepoint() method. Savepoints must occur within a transaction

395 10.1.6. Internal Savepoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396 10.1.7. Savepoints and PSQL . . . . . . . rdb$set_context('USER_SESSION', 'RecordsFound', RecCounter); select rdb$set_context('USER_TRANSACTION', 'Savepoints', 'Yes') from rdb$database Notes • The maximum number of variables in any single context is variables set with RDB$SET_CONTEXT() remain unchanged. • Any savepoints that were created after the one named are destroyed. Savepoints earlier than the one named are preserved, along with the named

7 Restart strategies ??? Vasiliki Kalavri | Boston University 2020 Reconfiguration with Savepoints ??? Vasiliki Kalavri | Boston University 2020 • Change parallelism • scale out to process increased • Checkpoints are automatically created and removed by Flink. • Savepoints are never automatically removed. 14 savepoint Savepoints: user-triggered checkpoints ??? Vasiliki Kalavri | Boston University

can be used to: • Open and close connections. • Execute queries. • Manage transactions (and savepoints). • Introspect tables, columns, indexes, and constraints. Peewee comes with support for SQLite will use savepoints. with db.atomic() as txn: perform_operation() with db.atomic() as nested_txn: perform_another_operation() Peewee supports nested transactions through the use of savepoints (for more that you use atomic(). Explicit Savepoints Just as you can explicitly create transactions, you can also explicitly create savepoints using the savepoint() method. Savepoints must occur within a transaction

567 12.1.6. Internal Savepoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 568 12.1.7. Savepoints and PSQL . . . . . . . rdb$set_context('USER_SESSION', 'RecordsFound', RecCounter); select rdb$set_context('USER_TRANSACTION', 'Savepoints', 'Yes') from rdb$database See also RDB$GET_CONTEXT() 8.2. Mathematical Functions 8.2.1. variables set with RDB$SET_CONTEXT() remain unchanged. • Any savepoints that were created after the one named are destroyed. Savepoints earlier than the one named are preserved, along with the named

can be used to: • Open and close connections. • Execute queries. • Manage transactions (and savepoints). • Introspect tables, columns, indexes, and constraints. Peewee comes with support for SQLite will use savepoints. with db.atomic() as txn: perform_operation() with db.atomic() as nested_txn: perform_another_operation() Peewee supports nested transactions through the use of savepoints (for more that you use atomic(). Explicit Savepoints Just as you can explicitly create transactions, you can also explicitly create savepoints using the savepoint() method. Savepoints must occur within a transaction

Understanding PROPAGATION_NESTED PROPAGATION_NESTED uses a single physical transaction with multiple savepoints that it can roll back to. Such partial rollbacks let an inner transaction scope trigger a rollback transaction despite some operations having been rolled back. This setting is typically mapped onto JDBC savepoints, so it works only with JDBC resource transactions. See Spring’s DataSourceTransactionManager. getConnection and can therefore be used in any case. The DataSourceTransactionManager class supports savepoints (PROPAGATION_NESTED), custom isolation levels, and timeouts that get applied as appropriate JDBC

the database, unless a transaction is active. See below for details. Django uses transactions or savepoints automatically to guarantee the integrity of ORM operations that require multiple queries, especially produces an exception, Django rolls back the transaction. You may perform subtransactions using savepoints in your view code, typically with the atomic() context manager. However, at the end of the view or rolls back the transaction when exiting the outermost block. You can disable the creation of savepoints for inner blocks by setting the savepoint argument to False. If an exception occurs, Django will