Accelerated transactions with precommit-time early lock release

Patent metadata

Field	Value
Publication number	US-9336262-B2
Application number	US-89861710-A
Country	US
Kind code	B2
Filing date	Oct 5, 2010
Priority date	Oct 5, 2010
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

A system, method and computer product for accelerating parallel database transactions. One or more data processors execute a first transaction on a database. The first transaction includes a transactional lock associated with each of one or more records to update the one or more records during the first transaction, and a pre-commit command to request acknowledgement of committing the updating of the one or more records during the first transaction. The one or more data processors execute a second transaction on the database in parallel with the first transaction. The second transaction includes a transactional lock associated with each of one or more records to update the one or more records during the second transaction, and a pre-commit command to request acknowledgement of committing the updating of the one or more records during the second transaction. The transactional locks of the first and second transactions are released before flushing log records associated with the first and second transactions.

First claim

The invention claimed is:

1. A method for accelerating parallel database transactions, the method comprising:
executing, by one or more data processors, a first transaction on a database, the first transaction including a transactional lock for each of one or more records to update the one or more records during the first transaction, and a pre-commit command to request acknowledgement of committing the updating of the one or more records during the first transaction;
executing, by the one or more data processors, a second transaction on the database in parallel with the first transaction, the second transaction including a transactional lock for each of one or more records to update the one or more records during the second transaction, and a pre-commit command to request acknowledgement of committing the updating of the one or more records during the second transaction;
waiting, by the one or more data processors, to execute an update of a record during the second transaction until a transactional lock of the first transaction is released; and
releasing the transactional locks of the first and second transactions before flushing log records for the first and second transactions;
wherein each pre-commit command for the first transaction and the second transaction is automatically generated based on a commit-dependent log sequence number (LSN);
wherein each version of an update to the one or more records is assigned a precommit timestamp at transaction precommit time and a postcommit timestamp at transaction postcommit time and a commit dependency of each version of the update to the one or more records is checked based on the assigned precommit timestamp when the commit-dependent LSN becomes larger than a current tail LSN;
wherein each LSN is associated with a lock table that associates time slots with lock information, and a transaction token that stores runtime context information of a transaction.

2. The method in accordance with claim 1 , further comprising:
receiving, by the one or more processors, a request to execute the first transaction from a client computer.

3. The method in accordance with claim 2 , further comprising:
sending, by the one or more processors, an acknowledgement of updating the one or more records to commit execution of the first transaction.

4. The method in accordance with claim 2 , further comprising:
receiving, by the one or more processors, a second request to execute the second transaction from a second client computer.

5. A method for accelerating parallel database transactions, the method comprising:
receiving, by one or more data processors, a request from a client network to execute a first transaction on a database;
executing, by one or more data processors, the first transaction on a database, the first transaction including a transactional lock for each of one or more records to update the one or more records during the first transaction, and a pre-commit command to request acknowledgement of committing the updating of the one or more records during the first transaction;
receiving, by the one or more data processors, a request from the client network to execute a second transaction on the database in parallel with the first transaction;
executing, by the one or more data processors, a second transaction on the database in parallel with the first transaction, the second transaction including a transactional for each of one or more records to update the one or more records during the second transaction, and a pre-commit command to request acknowledgement of committing the updating of the one or more records during the second transaction;
waiting, by the one or more data processors, to execute an update of a record during the second transaction until a transactional lock of the first transaction is released; and
releasing the transactional locks of the first and second transactions before flushing log records for the first and second transactions;
wherein each pre-commit command for the first transaction and the second transaction is automatically generated based on a commit-dependent log sequence number (LSN);
wherein each version of an update to the one or more records is assigned a precommit timestamp at transaction precommit time and a postcommit timestamp at transaction postcommit time and a commit dependency of each version of the update to the one or more records is checked based on the assigned precommit timestamp when the commit-dependent LSN becomes larger than a current tail LSN;
wherein each LSN is associated with a lock table that associates time slots with lock information, and a transaction token that stores runtime context information of a transaction.

6. The method in accordance with claim 5 , further comprising sending, by the one or more processors, an acknowledgement of updating the one or more records to commit execution of the first transaction.

7. A non-transitory computer program product for accelerating parallel database transactions, the product comprising a storage medium readable by at least one processor and storing instructions for execution by the at least one processor for:
executing, by one or more data processors, a first transaction on a database, the first transaction including a transactional lock for each of one or more records to update the one or more records during the first transaction, and a pre-commit command to request acknowledgement of committing the updating of the one or more records during the first transaction;
executing, by the one or more data processors, a second transaction on the database in parallel with the first transaction, the second transaction including a transactional lock for each of one or more records to update the one or more records during the second transaction, and a pre-commit command to request acknowledgement of committing the updating of the one or more records during the second transaction;
waiting, by the one or more data processors, to execute an update of a record during the second transaction until a transactional lock of the first transaction is released; and
releasing the transactional locks of the first and second transactions before flushing log records for the first and second transactions;
wherein each pre-commit command for the first transaction and the second transaction is automatically generated based on a commit-dependent log sequence number (LSN);
wherein each version of an update to the one or more records is assigned a precommit timestamp at transaction precommit time and a postcommit timestamp at transaction postcommit time and a commit dependency of each version of the update to the one or more records is checked based on the assigned precommit timestamp when the commit-dependent LSN becomes larger than a current tail LSN;
wherein each LSN is associated with a lock table that associates time slots with lock information, and a transaction token that stores runtime context information of a transaction.

8. The computer program product in accordance with claim 7 , wherein instructions for execution by the at least one processor further comprises:
receiving, by the one or more processors, a request to execute the first transaction from a client computer.

9. The computer program product in accordance with claim 8 , wherein instructions for execution by the at least one processor further comprises:
sending, by the one or more processors, an acknowledgement of updating the one or more records to commit execution of the first transaction.

10. The computer program product in accordance with claim 8 , wherein instructions for execution by the at least one processor further comprises:
receiving, by the one or more processors, a second request to execute the second tr

Assignees

• Lee Juchang
• Renkes Frank
• Hwang Sangyong
• Sap Se

Inventors

• Lee Juchang
• Renkes Frank
• Hwang Sangyong

Classifications

• G06F16/2379 Primary

  Updates performed during online database operations; commit processing · CPC title

• G06F16/24532

  of parallel queries · CPC title

• G06F16/2343

  Locking methods, e.g. distributed locking or locking implementation details · CPC title

• G06F16/2315

  Optimistic concurrency control · CPC title

• G06F17/30362

  Physics · mapped topic