shout out to ur mom

this vid is confusing, the lossy decomposition example has an error

2:25 revisit

worst case of binary search should be B not logB

For ARGMAX pt 2, why use the ALL keyword before the sub-query? Wouldn't it make more sense to use it at the start of the WHERE clause?

Difficult nested subqueries with correlation. Called relational "division"

**QUESTIONS** 1. What does the keyword IN do? 2. What is a nested sub-query? 3. What is a correlated sub-query? 4. What does the keyword EXISTS do? 5. What is the difference between ANY and ALL? **ANSWERS** 1. Allows to specify values in the WHERE clause 2. Runs first and once. The value returned is the value used in the outer/main query 3. A sub-query that executes for each tuple/row of the outer query 4. Returns TRUE if the sub-query returns one or more records 5. ANY will return TRUE should any records meet the conditions while ALL returns TRUE when _all_ the records meet the conditions

step 1：find boats a sailor has reversed step 2： these boats consist of all boats？（find the boats not in these boats，if find nothing ,it means these boats really consist of all boats） step 3： find sailors who have reversed all boats try something easier if the problem is hard

at 0:12 he licks his lips

thanks

Thanks a lot

what is this? explained nothing

I love jesus

useful！！❤❤ heart from china

What os check point, dirty page, clrLSN, LSN, redo, undo terms.

I just found this, and while it may not be "fresh", it is absolutely EPIC and timeless. The beauty of concurrency control algorithms remains art as well as science - and hey, innovation is still happening there 🙂

I still don't understand why it's needed and what's the use of it in real life.

Gold!

Is it a mistake that there is no 13, 17, and 30 anywhere in the leaf nodes of this tree?

how can solve the left-deep in a query

Very clear explanation, easy to understand

god

The "between" OP should also be allowed in the composite search key.

u saved my life broo thanks a lott

thank u

Thank you man, very helpful. 2 hours till exams and you made everything really clear

What are the steps of computing the average case of sorted file?

This is gonna save me.

zhian

🥲

yo that's complicated but so cool

The range search of sorted file can be faster!!! Keep using binary search when you get the first number!

god

god

Berkeley professor i cant understand sab you make me sleep

This is really good. Thank you sir.

Hi

This was very helpful!!! Thank you 🙏

awesome

its great

Thanks for the good videos. I am confused about writing an END log record for an Xact in the 'Committing' state without flushing the dirty pages before it. kzbin.info/www/bejne/rXanY2WdfqiHmpY. I searched the original paper, and the pseudo code shows that: "The only log records that may be written by this routine are end records for transactions that had totally rolled back before system failure, but for whom end records are missing". Is the paper talking about a different version of ARIES?

Better: use a thread library that works.

I actually thought databases were boring. :-)

Not buying the hash/sort duality. But mergesort and quicksort are informally dual: mergesort = simple split, recursive sort, fancy join quicksort = fancy split, recursive sort, simple join.

It's not 100% obvious how sorting and hashing work for duplicate detection. For sorting, see en.wikipedia.org/wiki/Weak_ordering For hashing, suppose we have a bucket with 100 elements in it. Are the elements unique ? Maybe, maybe not. So hashing by itself doesn't completely solve the problem.

Suppose we hash by gender, as in the earlier video. Then we have three values (M, F, O). This video makes it sound like all men are duplicates of each other, which makes no sense.

When we compare numbers, we have n1 <= n2 and n2 <= n1 implies n1 = n2. But when we compare address records by name, this axiom fails: r1 = "Smith, John, New York" and r2 = "Smith, John, California". To solve this problem, the C++ sort function uses a strict weak ordering: en.wikipedia.org/wiki/Weak_ordering

gigantic s

great content