how to find a record physically

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in a heap file, there are generally two ways to access data:

direct access with Record Id
- the record id contains a page id and a slot id
  - RID = (page_id, slot_number)
- dbms locates the page on disk using page id
- dbms looks up the slot in the page’s slot directory, retrieves record’s offset and length (normally fixed length), and returns the tuple
sequential scan
- scan page-by-page until the record is found or all records are read