Cannot understand the last part of JIT compilation and the introduction is so short. Why no students coming up questions? Is that class closing to the ending?
@andypavlo
3 жыл бұрын
The reason why I don't go into detail is because I have an entire lecture about it in the advanced class: kzitem.info/news/bejne/paye15uji4OmdKA
@Sam-sk3dz
3 жыл бұрын
@@andypavlo Thanks. I'll follow on and try to understand.
@eytehs
3 жыл бұрын
I don't like to show code... SQL does not count because it is beautiful - Andy Pavlo
@harshavardhanunnibhavi5993
4 жыл бұрын
What is the name of the system that would generate a single function instead of the tree for the query plan?
@andypavlo
4 жыл бұрын
I don't remember what you are referring to. Do you have a time in the lecture that this comes up?
@antonlastauka4898
4 жыл бұрын
@@andypavlo I guess it is here: kzitem.info/news/bejne/rWuEzoFtpKlneJw You are describing the system that is developed internally in CMU
@ameypatel5774
4 жыл бұрын
How does buffer pool bypass work? If the sequential scan operator will not store the fetched pages in the buffer pool(aka memory), how will it even scan it?
@andypavlo
4 жыл бұрын
The memory used for the bypass is private to the query (i.e., allocated on the heap by the worker). Other queries cannot see the contents of those pages. With a buffer pool, the pages are visible to all queries.
@siddharthabiswas2147
3 жыл бұрын
What is special about OLAP queries ?
@lingjin8917
5 жыл бұрын
what is the mean of offset in the "Late materialization" for the column storage. offset of what?
@abdulrahmansattar2873
4 жыл бұрын
Column offset in a page
@lebronsun8205
4 жыл бұрын
in column store, its like the index of every record
@angus10292
4 жыл бұрын
the slide on 49:53 , how does the DBMS figure out all the tuples it needs ? Isn't that the expected output from the DBMS ? or in other words, how can the DBMS know which tuples it needs before actually fetching them from disk ? I guess this is determined from the record ID , just before the access methods fetch pages/tuples ?
@djgreenmoon55
4 жыл бұрын
Say you have a B+ tree index on age, you know which leaf nodes include tuples with age < 30.
@AshishNegi1618
4 жыл бұрын
Instead of : read leaf node of Index and for each tuple fetch the data page => random IO for every tuple.. First sequential scan all leaf nodes of index => get all page ids that you need .. then fetch data pages in sorted order of page ids..
@AshishNegi1618
4 жыл бұрын
in index-scan, index should have all the columns for the filtering/where clause. Once final keys are identified, other columns are fetched from main table.
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