Table Full Scan/ Index Range Scan/ Index Full Scan

✅ Table Full Scan

• read all blocks in table to find data
• used for database optimization, optimizing query
• 👎🏻 can affect database performance if the table is big, query is complex

✅ Index Range Scan

• use index to read certain data
• use ROWID to find table record
• ROWID: point to where table record is saved on disk

✅ Index Full Scan

• not read all table, but read all index
• index is much smaller than table