Someone’s inability to disprove a claim is evidence that it’s true.

Everything that’s physically possible is also logically possible.

If we can’t give a scientific explanation of a phenomenon, then that phenomenon must have a supernatural/paranormal explanation.

Assuming that you have a three-frame buffer pool. Please show the buffer content given the workload listed in the table below using LRU and MRU strategies. We start from T1 and moves forward by one on each page reference. For your solution, underline the letter in the frame in the buffer pool each time that memory access caused a “miss” in the buffer pool (i.e., a page is read that is not currently in the buffer pool), when the page is put in the buffer pool. When the buffer pool has unused slots (such as at the beginning, when all slots are empty), it will put newly read data in the first unused slot.  The pages to be read from the disk are labeled A through D.  For each access, the page is pinned, and then immediately unpinned. Assume one page on disk fits perfectly with one frame on the buffer pool.   Time Page Read T1 A T2 B T3 C T4 D T5 B T6 C T7 D T8 C T9 D T10 A    1. In your answer, please create two buffer pools, one for LRU strategy and one for MRU strategy. You could create a similar buffer pool by click to table icon   Buffer Pool LRU strategy Time Frame 1 Frame 2 Frame 3 T1   A (example)     T2       T3       T4       T5       T6       T7       T8       T9       T10         MRU strategy Time Frame 1 Frame 2 Frame 3 T1   A (example)     T2       T3       T4       T5       T6       T7       T8       T9       T10         2. Which strategy is working better in this scenario? Please justify your answer.  

The first step in optimizing a query is

Selection condition: (age = 40 v  GPA >3.5) ∧  years > 2 (assuming age, GPA, and years are in the same relation) Which index(es) below that is/are most effective in executing this query with the above-mentioned selection condition?

Consider a relation R with five attributes X, Y, Z, W, V. You are given the following dependencies: {X -> Y, YZ-> W, X->Z} List all candidate keys for R. Please justify your answer.   Is R in 3NF? Please justify.   Is R in BCNF? Please justify.

What is wrong with the following query?                       SELECT sname, count(snum)                 FROM Enroll;

What is the information stored in a catalog of database (in which metadata is stored) ?

Given a relation Criminal(id, name, crime) containing 1,000,000 records, where each data page of the relation holds 100 records. Assume that Criminal.id is a candidate key for this relation, with values lying in the range 0 to 999,999, and that Criminal is stored and sorted in Criminal.id order. a. For each of the following relational algebra queries: (i)