DB File Structures

  • Unordered Heap Files
  • Clustered Heap Files
    • Records and pages are grouped
  • Sorted Files
    • Pages and records are in sorted order
  • Index Files
    • B+ Trees, Linear Hashing, …
    • May contain records or point to records in other files


  • Fixed Length Records (FLR)
  • Variable Length Records (VLR)
    • Slotted Page
      • each page uses a page footer that maintains a slot directory tracking slot count, a free space pointer, and entries.
      • The slot count tracks the total number of slots. This includes both filled and empty slots.
      • The free space pointer points to the next free position within the page.
      • Full when footer and records come together.
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