Обсуждение: some questions in postgresql developping
Hello,
I’m a student from Nankai University in China. Now I and my team do a project which aims to integrate XML to Postgresql. What I do is to complete the function of XML Update.
Now I’m researching in concurrency control. I have read the code about the concurrency control for a long time and I’m confident that I know it much. But I am puzzled that why we need to lock tuple. I think locking transaction is sufficient. I don’t think the tuple lock is good at improving executing rate or anything.
I am wishing for your reply.
Best Regards,
--Huang Xiaocheng
--Database & Information System Lab, Nankai University, China
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2009/12/7 黄晓骋 <huangxclife@gmail.com>: > I’m a student from Nankai University in China. Now I and my team do a > project which aims to integrate XML to Postgresql. What I do is to complete > the function of XML Update. > > Now I’m researching in concurrency control. I have read the code about the > concurrency control for a long time and I’m confident that I know it much. > But I am puzzled that why we need to lock tuple. I think locking transaction > is sufficient. I don’t think the tuple lock is good at improving executing > rate or anything. The purpose of locking is to preserve correct semantics in the face of concurrent activity, not to improve execution speed. The reasons why tuple locking is necessary should be covered in any introductory database textbook. ...Robert