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Utku
  • Member for 7 years, 8 months
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Advantages and Disadvantages to using ENUM vs Integer types?
The article suggests to use a good old table, instead of ENUM types. Should we add this to the answer?
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Data model to hold attendance records?
@dezso Added some relations.
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Data model to hold attendance records?
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How does MySQL still function even though I move .ibd file to arbitrary places?
One last question: Why doesn't mysql put a lock on .ibd files so that no other process will be able to mess with them? Does it make sense to mess with .ibd files using anything but mysql?
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How does MySQL still function even though I move .ibd file to arbitrary places?
Regarding editing an .ibd file: When I edit an .ibd file using vim and save my changes, my changes are, for sure, written into the disk right? However since mysql has cached the file, it does not see these changes. Furthermore, the changes I made using vim will in fact be overwritten when mysql decides to write the memory mapped .ibd file back to disk, which will completely remove any changes made by my manual edits, and the result will be as if I did not make any edits at all. Am I correct about these?
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How does MySQL still function even though I move .ibd file to arbitrary places?
I was interacting via terminal and I wrote quit but I guess this only logs out of the account. In other words, I did not restart the server. But still, when I make an insert, how does that data appear in person.ibd? Or is person.ibd doesn't read from disk, but it reads from memory?
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How to interpret correlated subqueries?
Thank you Rick. Actually I am trying to understand the logic behind SQL. I mean, why it behaves in this way rather than another. Especially in the edit part of my question, I tried to clarify the question. (The part where I ask why the query I gave executes in this way, rather than the another way that I described). Would you happen to have any ideas about that part as well? By the way, if that edit seems like it should be asked as a new question, I can do that.
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How to interpret correlated subqueries?
Thank you very much. Actually, regarding: You should think in terms of sets of data (think set arithmetic), not in terms of iterations and comparisons per iteration. That's what I want to achieve but I can't manage to fully do so right now. For example, how can I think correlated subqueries in terms of set arithmetic?
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How to interpret correlated subqueries?
Maybe I should post that one as a new question since this one is already very cluttered in this form.
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How to interpret correlated subqueries?
@ypercube Could you elaborate more with an answer?