Hi
最近在对比CALC的论文研究MOT检查点代码，发现capture阶段向磁盘写数据的代码，好像没有实现CALC论文中所讲的pCALC，每次做checkpoint，将MOT表所有记录都写到磁盘文件（CheckpointWorkerPool::WriteTableDataFile）中，而不是只保存修改了的记录，我找不到实现pCALC的代码，这样做checkpoint是不是代价太大了？而且我在代码中发现"MOT does not support incremental checkpoint"，这是不是说目前不支持CALC中的pCALC？如果我的理解有问题，请纠正。
Recently, I was studying the MOT checkpoint code comparing with CALC paper, and found no implemention of pCALC, which means, in the capture phase, all MOT records are written to the disk(CheckpointWorkerPool::WriteTableDataFile), not just updated records. Is it too expensive to save all records of MOT tables? And I found some messages in code like "MOT does not support incremental checkpoint", does that mean pCALC is not supported in OpenGauss currently？Please correct me, if my understanding is wrong.
新大陆软件 秦浩 mobile: 17625988619 e-mail:qinhao@newland.com.cn
Hi, pCALC (partial checkpoint) is an extension to the CALC algorithm and yes, it is not implemented in openGauss. MOT only supports full checkpoint now. Regarding the overhead, there will be I/O overhead whenever checkpoint happens, but it won't block or affect normal user operations.
Regards, Vinoth ________________________________ From: qinhao@newland.com.cn qinhao@newland.com.cn Sent: Tuesday, June 21, 2022 3:22 PM To: community community@opengauss.org Subject: [Community] OpenGauss没有实现pCALC吗？（OpenGauss does not implement pCALC？）
Hi
最近在对比CALC的论文研究MOT检查点代码，发现capture阶段向磁盘写数据的代码，好像没有实现CALC论文中所讲的pCALC，每次做checkpoint，将MOT表所有记录都写到磁盘文件（CheckpointWorkerPool::WriteTableDataFile）中，而不是只保存修改了的记录，我找不到实现pCALC的代码，这样做checkpoint是不是代价太大了？而且我在代码中发现"MOT does not support incremental checkpoint"，这是不是说目前不支持CALC中的pCALC？如果我的理解有问题，请纠正。
Recently, I was studying the MOT checkpoint code comparing with CALC paper, and found no implemention of pCALC, which means, in the capture phase, all MOT records are written to the disk(CheckpointWorkerPool::WriteTableDataFile), not just updated records. Is it too expensive to save all records of MOT tables? And I found some messages in code like "MOT does not support incremental checkpoint", does that mean pCALC is not supported in OpenGauss currently？Please correct me, if my understanding is wrong.
新大陆软件 秦浩 mobile: 17625988619 e-mail:qinhao@newland.com.cn
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Thank you Vinoth.
However, I still think MOT should support incremental checkpoint.
新大陆软件 秦浩 mobile: 17625988619 e-mail:qinhao@newland.com.cn
发件人： Vinoth Veeraraghavan 发送时间： 2022-06-22 10:32 收件人： qinhao@newland.com.cn; community 主题： Re: [Community] OpenGauss没有实现pCALC吗？（OpenGauss does not implement pCALC？） Hi, pCALC (partial checkpoint) is an extension to the CALC algorithm and yes, it is not implemented in openGauss. MOT only supports full checkpoint now. Regarding the overhead, there will be I/O overhead whenever checkpoint happens, but it won't block or affect normal user operations.
Regards, Vinoth
From: qinhao@newland.com.cn qinhao@newland.com.cn Sent: Tuesday, June 21, 2022 3:22 PM To: community community@opengauss.org Subject: [Community] OpenGauss没有实现pCALC吗？（OpenGauss does not implement pCALC？）
Hi
最近在对比CALC的论文研究MOT检查点代码，发现capture阶段向磁盘写数据的代码，好像没有实现CALC论文中所讲的pCALC，每次做checkpoint，将MOT表所有记录都写到磁盘文件（CheckpointWorkerPool::WriteTableDataFile）中，而不是只保存修改了的记录，我找不到实现pCALC的代码，这样做checkpoint是不是代价太大了？而且我在代码中发现"MOT does not support incremental checkpoint"，这是不是说目前不支持CALC中的pCALC？如果我的理解有问题，请纠正。
Recently, I was studying the MOT checkpoint code comparing with CALC paper, and found no implemention of pCALC, which means, in the capture phase, all MOT records are written to the disk(CheckpointWorkerPool::WriteTableDataFile), not just updated records. Is it too expensive to save all records of MOT tables? And I found some messages in code like "MOT does not support incremental checkpoint", does that mean pCALC is not supported in OpenGauss currently？Please correct me, if my understanding is wrong.
新大陆软件 秦浩 mobile: 17625988619 e-mail:qinhao@newland.com.cn
_______________________________________________ Community mailing list -- community@opengauss.org To unsubscribe send an email to community-leave@opengauss.org
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Vinoth Veeraraghavan