mtdewcmu

75 ms·

751.
by mtdewcmu 13y ago
Processing financial transactions is the canonical example of when you need ACID guarantees. Using a trendy NoSQL database there is ridiculous.
752.
by mtdewcmu 13y ago
You might have to give the join a name in the query in either case, because what if you want to go two levels deep, e.g. join in your boss's boss? Both can't be manager. All I'm interested in is making the queries more concis
753.
by mtdewcmu 13y ago
It's hipster haves versus hipster have-nots. Where's the sense of hipster fraternity?
754.
by mtdewcmu 13y ago
I've noticed that the truly down-and-out seem to take further misfortune in stride. They expect it.
755.
by mtdewcmu 13y ago
I'd leave it to experts to design the best syntax, because they could foresee all the possible ramifications of different choices. I think we've clearly articulated the ends and some potential means.
756.
by mtdewcmu 13y ago
That's pretty much it. If you want to do it with a minimum of new syntax, you could defer naming the join until the select, as you normally would: CREATE TABLE emp ( emp_id INTEGER PRIMARY KEY, manager_id INTEGER FOREIGN KE
757.
by mtdewcmu 13y ago
Sets are the most elemental way to abstract data. Not all data are graphs, but all data are sets. A graph is a set of vertices and a set of edges. So there's no loss of generality in using sets.
758.
by mtdewcmu 13y ago
A foreign key is frequently just an integer. You can create a foreign key constraint that checks that the integer exists in a field in another table, but that information isn't used by the database for anything other than checking that
759.
by mtdewcmu 13y ago
>in the case of a user with multiple shipping addresses...join user on address => you get the same user record for every instance of address, which then has to be consolidated in code One solution is to use two queries: one to get t
760.
by mtdewcmu 13y ago
There isn't much you can't do with a modern RDBMS. If you want to denormalize relationships, you can do that. If the queries are too repetitive or hard to write, you can use views or stored procedures. One thing that I find peculi
761.
by mtdewcmu 13y ago
I don't get the supposed benefits of direct links over joins. Index lookups are O(log n) or close to O(1) for B-tree and hash indexes, respectively. You can model any kind of graph in a relational database.
762.
by mtdewcmu 13y ago
Fun. A $25,000 Pyramid style game with Unix subjects would be entertaining.
763.
by mtdewcmu 13y ago
Codd nailed it with the relational model.
764.
by mtdewcmu 13y ago
Transaction is being used in different senses there. The first sense refers to an OLTP workload. The second sense refers to ACID transactions. The in-memory architecture would relate to details of how the database manages memory internally.
765.
by mtdewcmu 13y ago
I noticed that there is no delta compression until objects get incorporated into a pack. >Think of each branch as a pointer. Then realize that you can make that pointer point anywhere on the DAG, even to parts of the DAG that have no co
766.
by mtdewcmu 13y ago
I see. I started reading the internals chapter at[1]. This free book seems better than the O'Reilly book, which I bought. So the DAG is actually stored inside objects. The contents of the objects directory could be described by a relat
767.
by mtdewcmu 13y ago
The idea is to make it less monolithic. I'm digging more into the inner workings of git now. The functionality might already be in there, just not obvious.
768.
by mtdewcmu 13y ago
I'm guessing that the reason each branch has its own history is probably related to the goal of only appending new entries at the end of things. Since any branch can be under development, they need their own files. It sort of makes sen
769.
by mtdewcmu 13y ago
>I've never looked at .git/logs, but it looks like that is used by the `git reflog` command. It's basically a history (or log) of every commit that a particular reference has pointed to[1]. For example, I cloned the git s
770.
by mtdewcmu 13y ago
It looks like .git/logs contains the history. It looks like the file format is a space-separated list, with the format "$parentcommitsha1 $newcommitsha1 ... $commitmessage". That's fairly comprehensible. What are the SHA
771.
by mtdewcmu 13y ago
When you look at something designed by a person, you can intuit what they were doing and judge it as good or sloppy. Nature requires a completely different type of thinking. It's ultimately unhelpful to anthropomorphize nature.
772.
by mtdewcmu 13y ago
I've read a lot about git. The docs generally don't pick apart what's inside the .git directory.
773.
by mtdewcmu 13y ago
I meant to raise the question of whether it's worth trying to expunge something sensitive from git. You'd have to track down all the clones of that repository. Even if you thought it was gone, it would be prudent to change the pas
774.
by mtdewcmu 13y ago
The problem is probably that you have to train in two separate fields to be competent in computer science and biology, and that's not going to be common.
775.
by mtdewcmu 13y ago
You have to understand things on their own terms. A lot of times you can find a biological process that resembles something in computer science, but you shouldn't take the analogy too far. Nature doesn't know what a computer is, s
776.
by mtdewcmu 13y ago
It's hard to know how elegant and simple something can be made. git is a nice tool, but we shouldn't assume that it's the last word and can't be improved upon.
777.
by mtdewcmu 13y ago
It might be a better idea to just change the password.
778.
by mtdewcmu 13y ago
At the last job where I used git, I'd work in a separate branch, and I started using `git merge --squash` to merge into the main branch to keep the history from getting too difficult to follow. When git merges a bunch of different hist
779.
by mtdewcmu 13y ago
You probably wanted `git merge --abort`. It's not very clear what the various states are that git can be in. There seems to be a 'fixing merge conflict' state, and it's hard to find documentation that warns you about thi
780.
by mtdewcmu 13y ago
Is the history stored as a text file somewhere that you can just edit? I sometimes wish git were a bit more transparent and less of a black box.

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