mobilephone724's Blog


Why does the blog is written in English(为什么使用英文写博客)? I don’t know how to translate many professional terms into Chinese, and people may be more familiar with the terms in English rather than Chinese.(我不知道如何使用中文去表述很多专业名词,而且人们应该更熟悉英文表述) Most content published on the blog is about technology in computer science, I believe there is no barrier for relavant people to read the blog in English(博客中大多数内容和计算机技术相关,相关人员应该没有阅读英语的障碍) So English can’t be avoided and swith input method between Chinese and English isn’t convenient(写英文无法避免而且中英文输入法切换并不方便) It’s a good way to practice English(这也是个练习英文的好方式) If anything isn’t described clearly or wrong, please contact me ASAP.

Phantoms Predicate Lock

Intro Phantoms The idea comes from which is an object, the table or its each tuple. The former is unacceptable. But the latter, when tupples appear or disappear from a table, select statements can conflict with the change, which is called the phantoms. Predicate Lock Although predicate lock is too expensive, it’s a good way to think about things. predicate lock can be writen like 1 <tid, [slock|xlock], predicate> Two predicate locks are compatible iff

Principles_Of_Economic_chap1: Ten Principle of Economic

how people make decisions people face trade-offs Efficiency: the property of society getting the most it can from its scare resources Equality: the property of distributing economic prosperity uniformly among the members of society the cost of something is what you give up to get it opportunity cost: whatever must be given up to obtain some item, such materials and time which means how much you can earn during this time.

Basic Knowledge of Database Log

Primitive Operation if Transactions There are three address spaces that transaction interact in important ways: The space of disk blocks holding the database elements. The memory address space managed by buffer manager. The local address space of the transaction. To describe a transaction, we need some operation notions:(X below is a database element while t is a local varible, and we suppose a database element is no larger than a single block)

basic of cublasDgemm

concept cublasDgemm is a convenient function in cublas to compute the product of two matrix, while letter 'D' in cublasDgemm means double. Before reading this post, basic cuda functions like cudaMalloc are what you are supposed to know. basic use Definition of this function 1 2 3 4 5 6 7 8 cublasStatus_t cublasDgemm(cublasHandle_t handle, cublasOperation_t transa, cublasOperation_t transb, int m, int n, int k, const double *alpha, const double *A, int lda, const double *B, int ldb, const double *beta, double *C, int ldc) Basic information of parameters is show in this page.