‫So B plus three and DBMS considerations, take a sip of tea, take a sip of coffee, relax a little
‫bit.
‫I know it's a long video, guys, but I think I think we need to discuss these details.
‫You can pause the video and come back later.
‫All right.
‫This is there is there is a lot of content there.
‫Ask me questions.
‫Ask questions as you as you encounter them.
‫But this is very, very interesting to understand now.
‫So B plus trees and DBMS considerations, but there is an additional cost here, which is the leaf pointer.
‫Again, for, for instance, my sequel, A.B. PostgreSQL Sever all have this leaf pointers that points
‫to the next of the next leaf point in the B plus three leaves leaf nodes wired tiger in Mongo DB.
‫Yes, Mongo TV does use a B plus trees through this wired tiger database engine, which I have.
‫I have a lecture about data database engines.
‫Right.
‫Talk about that and why a tiger is a B plus three based engine.
‫And also they have a variant like structure mastery that that doesn't have this pointer from forfour
‫design decisions.
‫Those guys are smart.
‫They only include things where they absolutely.
‫This is like, OK, I have quiz, who cares?
‫You're not going to do a ranch cause a mango, for instance, OK?
‫You're not going to search for a range of keys.
‫Don't do that.
‫One node fits RDBMS page.
‫As I discussed, most differences do that can also fit internal nodes easily memory for fast reversal
‫because the nodes are now tinier.
‫I guess you can post a lot.
‫A lot, a lot of elements right in these internal nodes.
‫You can fit these internal nodes in memory easier.
‫So the traversal a single IO will give you way more elements.
‫As a result, it's a way faster.
‫Plus this again, it really depends on what are you indexing on this canford and memory fits at Gwynedd
‫or yolked.
‫It's not as easy for the memory, but still can usually the the internals as not as busy as the leaf
‫nodes in a P blusterous leave nodes can live in the data files in the heap.
‫That does absolutely fine.
‫It is.
‫Obviously you can try to put them in memory, but if the values, the value that points to is expensive,
‫then sometimes it is not possible.
‫Most Divinities B blusterous.
‫So is an example of the storage cost here.
‫This really I said should between Cote's here but doesn't have to write.
‫The B3 index works best when it's in memory.
‫So when you load up your database, let's say you have a table with five indexes, you can try to put
‫all the indexes of memory and you can check the sizes of the indexes by doing a query on the database
‫and say, see, can I fit this entire index in memory?
‫Most of the times the indexes are tiny, like if you have don't have large files, but if it's if it's
‫large, there's some databases.
‫Make that choice.
‫OK, I'm going to only put the internal nodes in memory so that my traversal are so fast because I cache
‫the page and these are tiny.
‫Right.
‫And Usry not necessarily time because these are pages of the same size, but I have way more elements
‫and as a result I can traverse way more and this could fit in disk.
‫But you can definitely put in memory nothing that stops you from doing that by.
‫If they fit again, it really depends on this on this pointer and also depends on what you're working
‫on, right.