Index Terminology
Most generally, index is a list of value/address pairs
- Each pair is an index “entry”
- Value is the index “key”
- Address will point to a data record, or to a data page
There might be many records on a page
- The assumption is that the value/address pair will be much smaller in size than the full record
If index is small, a copy can be maintained in memory!
- Permanent disk copy is still needed