For the view of Exercise 4.18, explain why the database system would not allow a tuple to be inserted into the database through this view.
For reference
For the database of Figure 4.12, write a query to find the ID of each employee with no manager. Note that an employee may simply have no manager listed or may have a null manager. Write your query using an outer join and then write it again using no outer join at all.
OUTER JOIN
select e.ID from employee e left outer join manages m on e.ID = m.ID
where m.manager_id is null;
NO OUTER
select e.ID from employee e where e.ID not in (select m.ID from manages m) or e.ID in (select m.ID from manages m where m.manager_id is null);
Answer:
The questions are used to secure and identify you furthermore. Answering personal questions that only you can answer will deter someone from hacking into your account that easily.
Explanation:
Answer:
Automated targeting
Explanation:
Display Automated Targeting is an automated targeting option within the Audience settings of the display campaigns that gives Google full right to show your ads to an audience that is “similar” to the one you specified.
Answer:
Some of the qualities of the installed memory which HWiNFO can reveal are:
- Date of manufacture
- Memory type
- Speed of memory
Explanation:
HWiNFO is an open-source systems information app/tool which Windows users can utilize as they best wish. It helps to detect information about the make-up of computers especially hardware.
If you used HWiNFO to diagnose the memory, the following information will be called up:
- the total size of the memory and its current performance settings
- the size of each module, its manufacturer, and model
- Date of manufacture
- Memory type
- Speed of memory
- supported burst lengths and module timings,
- write recovery time etc.
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