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    I‘ll try to explain it  in  English  for improving my English writing skill.

    Data storage management is  the lowest  layer in the DBMS architecture.
    It consist of  2  main component:the  disk space manager(storage manager) and the buffer manager.

First of all, we must clarify 2 concepts: page and block.
    page is a logical concept while block is a physical concept which means the data unit  storing in disk.

Then, we ‘ll see the 2 component.

Storage manager(SM)
Responsibility:
- allocate/deallocate a page
- read/write a page

Problem we must solve:
- how to keep track of free block

Buffer manager(BM)
Responsibility:
- bring the requested page from the upper level to the  buffer pool

Problem we must solve:
- “Address Transformation”. How we can know which frame in the buffer pool the requested page corresponds to?
-
“Replacement Policies”.Which frame we should choose to replace if  the
buffer pool is full? And we must write the frame into disk is the 
frame  is  changed  after it brought into the buffer pool.
- “Concurrency Control”. What if a page is requested by several transactions.

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        最近时间比较充裕，决定把数据库系统实现重新看一遍，以前在dbclub学的时候没怎么深入。另外，Standford的这门课程有个RedBase Project,可以参考实现一个小型的RDBMS，正好拿来实现一下。

General picture of where a DBMS sits:

What you’ll build in this class:

Closer look at DBMS, File System, and Disk:

Components of DBMS:

Missing from figure:

• Query results returned to User/Application
• Buffer Manager or Index/Record Managers call Concurrency Control
• Separate Table Manager
• Many, many (many!) details…

RedBase architecture:

Legend:

• PF: Paged File
• RM: Record Management
• IX: Indexing
• SM: System Management (DDL, utilities)
• QL: Query Language
• EX: Extension

Correspondence between RedBase and DBMS components:

• PF = Storage Manager + Buffer Manager
• RM = Record Manager
• IX = Index Manager
• SM = DDL Processor (+ misc. utilities)
• QL = Query Checker, Query Optimizer (simple), Execution Engine
• Command parser = Query Parser

从ssos师兄的主页上看到的Research Interest，十分精辟

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