Database

BufferPool

Transfering data between memory and disk

Buffer Pool Manager

high

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typedef char byte;
#define 4*1024 PageSize
#define 10 FrameNumber
//In memory

//BufferPool
byte BufferPool [FrameNumber][PageSize];

//PageTable
typedef struct PageTableEntry{
    byte* ptr ;
    bool dirty ;
    bool pin ;
    int counter ;
}

byte* PageTable [FrameNumber];
PageTable[0].ptr = BufferPool[3]; // frame0 -> page3
PageTable[0].dirty = false; // Not accessed yet
PageTable[0].pin = true ; // Do not swap the page out
PageTable[0].counter = 0;
...

Allocate strategy

  • Multiple Buffer Pool (each one can have different policies)
  • Pre-fetching

Replacement policies