Slideshow:
Places where you can find a
disk block or
record
Identifying a block/record on disk:
block address, record address, database address
A record address is an extension of a block address (they are very similar)
I will often use record address and block address interchangably
Identifying a block/record in memory:
(virtual) memory address
Summary: 2 ways to identify
block/records
- A (disk) block or a
record can be
found:
- On disk
- In (computer) memory
- On disk
- Terminology:
- A disk block is identified
by a block address
- A record
stored on disk is
identified
by a record address
- The block address and the
record address are
called:
- Database addresses
Note:
- A record address is an
extension of a
block address
(they are very similar ---
see discussion below)
- I will often use: "block/record address" and handle both topics at the same time
- A disk block is identified
by a block address
- Fact:
- A disk block/record must be in memory if you want to perform any operation to the data in the block/record
- Identifying a block/record
when it is in memory:
- A block/record in memory is identified by its (virtual) memory address (paging)
- There are 2 types of
address to
identify a
block/record:
- Database Address:
used to
identifies data (block or record) stored on
disk
- (Virtual) memory address: used to identify data (block or record) stored in (virtual) memory
Graphically:
- Database Address:
used to
identifies data (block or record) stored on
disk