Database Reference
In-Depth Information
Database before updates
282.......431.50
Ryan
Database on disk
Elena
Step 1 DBMS reads data from the database into RAM for Ryan
235
282.......431.50
Ryan
Database on disk
Elena
Step 2 DBMS reads data from the database into RAM for Elena
282.......431.50
282.......431.50
Ryan
Database on disk
Elena
Step 3 Ryan changes data in RAM
282.......431.50
282.......431.50
Ryan
Database on disk
Elena
Step 4 Elena updates data in RAM
282.......331.50
282.......431.50
Ryan
Database on disk
Elena
(continued)
FIGURE 7-6
Ryan's and Elena's updates to the database result in a lost update
(continued)
