故障转移集群中的 Hekaton 事务日志是否比平时大？
Are Hekaton transaction logs larger than usual in a failover cluster?
在几天前的一次会议上，有人在描述使用 Hekaton in-memory 表的 AlwaysOn SQL 集群的挑战时说 "using Hekaton increases the size of the transaction logs which increases the time to fail over"。我不是 SQL 专家，所以想知道这是否属实，如果是，是什么让 Hekaton 事务日志比没有 Hekaton 时更大？
我认为情况恰恰相反。事务记录是一个逻辑事务，它描述事务而不是与非内存table。
一起对索引进行的所有修改。
The log contains the logical effects of committed transactions
sufficient to redo the transaction. The changes are recorded as
insertions and deletions of row versions labeled with the table
they belong to. No undo information is logged.
Hekaton index operations are not logged. All indexes are reconstructed
on recovery.
Checkpoints are in effect a compressed representation of the
log. Checkpoints allow the log to be truncated and improve
crash recovery performance.
Since the tail of the transaction log is typically a bottleneck, reducing
the number of log records appended to the log can improve
scalability and significantly increase efficiency. Furthermore the
content of the log for each transaction requires less space than systems
that generate one log record per operation
有关 Hekaton 的 Microsoft 文档包含这些详细信息。
http://research.microsoft.com/pubs/193594/Hekaton%20-%20Sigmod2013%20final.pdf
我同意检查点应该改进崩溃恢复。
话虽如此，恢复 Hekaton 日志记录的速度非常快，因为该进程执行内存分配和一些计算比执行磁盘操作要小得多。
Hekaton 在 Azure（2015 年 11 月）中作为预览版提供，因此您可以在那里尝试您的工作负载。 https://azure.microsoft.com/en-us/blog/azure-sql-database-in-memory-oltp-real-time-operational-analytics-now-in-public-preview/
在几天前的一次会议上，有人在描述使用 Hekaton in-memory 表的 AlwaysOn SQL 集群的挑战时说 "using Hekaton increases the size of the transaction logs which increases the time to fail over"。我不是 SQL 专家，所以想知道这是否属实，如果是，是什么让 Hekaton 事务日志比没有 Hekaton 时更大？
我认为情况恰恰相反。事务记录是一个逻辑事务，它描述事务而不是与非内存table。
一起对索引进行的所有修改。The log contains the logical effects of committed transactions sufficient to redo the transaction. The changes are recorded as insertions and deletions of row versions labeled with the table they belong to. No undo information is logged.
Hekaton index operations are not logged. All indexes are reconstructed on recovery.
Checkpoints are in effect a compressed representation of the log. Checkpoints allow the log to be truncated and improve crash recovery performance.
Since the tail of the transaction log is typically a bottleneck, reducing the number of log records appended to the log can improve scalability and significantly increase efficiency. Furthermore the content of the log for each transaction requires less space than systems that generate one log record per operation
有关 Hekaton 的 Microsoft 文档包含这些详细信息。
http://research.microsoft.com/pubs/193594/Hekaton%20-%20Sigmod2013%20final.pdf
我同意检查点应该改进崩溃恢复。
话虽如此，恢复 Hekaton 日志记录的速度非常快，因为该进程执行内存分配和一些计算比执行磁盘操作要小得多。
Hekaton 在 Azure（2015 年 11 月）中作为预览版提供，因此您可以在那里尝试您的工作负载。 https://azure.microsoft.com/en-us/blog/azure-sql-database-in-memory-oltp-real-time-operational-analytics-now-in-public-preview/