Atomicity (database systems) Puns

They both seem to have a similar definition that every core should see the same ordering of writes but what is the exact difference?

So I'm going through Open Zeppelin's ERC20 contract template and I have a question about the order of operations in the transferFrom function. If I understand that function correctly it assumes the person calling transferFrom has been given an allowance by spender to spend their funds. The caller of the function then transfers ownership of spenders funds to recipient. What's weird to me is the first thing that function does is transfer ownership from sender to recipient. After it does that it checks to see _msgSender has enough allowance to do this and throws an error if they don't.

Why is it okay to do this check after transfer has already been called? I'm guessing it has something to do with the atomicity of state updates in the contract. If the second part fails then the initial transfer doesn't actually go through?

I asked this question in the zfs github, and haven't got a reply yet. I'm unsure whether this is the right place to ask or not. Here is a shorter transcript:

Hi, I'm trying to find some documentation concerning behavior not specified by POSIX. Specifically I would like to know what is the minimum set of POSIX syscalls required so that writing to a file is atomic & durable in the case of a crash in ZFS. In other words, if the OS/FS crashes or there is a power outage during a write to a file, the user space application won't see the corrupted data on the subsequent reboot, or at least will be able to detect and discard the corrupted file. I'm not looking for a portable solution, just ZFS.

This behavior is currently possible by strictly relying on POSIX behavior, but its really painful and slow. But even if you do everything correctly, you still run in the issue of most classical file systems potentially corrupting themselves on power failure (even XFS AFAIK) so you need to run fsck periodically.

Hello Linux Community!

I hope everyone is having a great week!!

I'm working on a hobby project that's written in C++ and some Perl. We are using RockDB as storage engine.

The project is a NoSQL database called Beryl. I'm dedicating my free time for this, and is just to learn more about databases, which I happen to enjoy a lot!

The DB only works in Linux at the time..

I'd love to get some feedback, even if you're a database amateur like me. Also, feel free to open an issue or DM me. I'm open to collaborations!! Any kind of collaboration would be appreciated 👍

Docs: https://docs.beryl.dev/

Github: https://github.com/beryldb/beryldb

Client (for terminals): https://github.com/beryldb/beryldb-cli

Amid the extended look into Arizona's election system and the results of the 2020 general presidential election, Arizona State Senate President Karen Fann wrote a letter asking for a meeting to resolve supposed disparities in Maricopa County's final vote tallies, as uncovered by the an audit of that election.

Fann stated that that Election Management System's database, which information was subject to a subpoena by the state senate, has been deleted, according to the Arizona Independent News Network.

Fann's letter to Jack Sellers, chair of the Maricopa County Board of Supervisors, reads "We have recently discovered that the entire 'Database' directory from the D drive of the machine 'EMSPrimary' has been deleted. This removes election related details that appear to have been covered by the subpoena."

"This suggests that the main database for all election related data for the November 2020 General Election has been removed. Can you please advise as to why these folders were deleted, and whether there are any backups that may contain the deleted folders?"

The Arizona audit is continuing, and Florida-based cyber-security firm Cyber Ninjas has been contracted to "oversee an unprecedented, partisan review of the 2020 election in Arizona’s largest county. They are conducting a hand recount of all 2.1 million ballots and looking into baseless conspiracy theories suggesting there were problems with the election, which have grown popular with supporters of former President Donald Trump," according to the AP.

The AP reported additionally that Sellers "did not directly respond to Fann's request for county officials to answer questions at the Senate on Tuesday, but said the county will hold its own public meeting the day before 'to refute lies and lay out facts about these issues.'"

The Biden administration, The Daily Wire reports, attempted to put a halt to the audit. The DOJ's head of the civil rights division, Pamela S. Karlan, wrote "that the recount of nearly 2.1 million ballots in Maricopa County by a private contractor may not comply with federal law, which requires that ballots be securely maintained for 22 months following a federal election."

"We have a concern that Maricopa County election records, which are required by federal law to be retained and preserved, are no longer under the ultimate control of elections officials, are not being adequately safeguarded by contractors, and are at risk of damage or loss," Karlan wrote.

Source: thepostmillenni

Hello everyone,

Maybe one of you can shed light into this. I work for a company and we use databases to store data (duh). That said our job is not to maintain the database, or in other words anything associated with database management, but only import and exporting the data in different ways and forms.

Today a colleague hit me up and wondered why 2 cases that want the same data had significantly different query times.

For simplicity sake I will call the database simply database and the system database master (since it's name is master).

Following are the 2 queries:

Use master
Select x from database.dbo.table 



Use database
Select x from table

The first one gives a result after 1-2 seconds, 52 lines. The second one gives a result after ~9 minutes, also the same 52 lines.

My theory is that this is due to priority and the system database called master receives the highest priority to be executed, while using the normal database just puts it at the end of all requests, meaning it will be done whenever it reaches spot 1.

I sadly don't have more information, the only difference is that one uses the system database master as database but makes a select into another database. Are there other possibilities as to why this happens?

I need to learn Databases, Operating Systems, Computer Science algorithms, Computer Networks, Computer Security, etc. Can I learn all those subjects at UDACITY?

I already have a nice job. I do not want to switch careers. I have a bachelor's degree in mathematics. I do not need a second bachelor's degree. I work as an analyst. I have found that I can learn those subjects at Oregon State University Computer Science Postbacc (OSU). However, UDACITY is cheaper than OSU. Is UDACITY equal or better than a university for learning?

Hi all,

I am about to complete my first semester in the program and I’ll be choosing a class for the summer. I’m considering taking the CS 6400 DB Systems class but I’ve read terrible reviews about the course on OMSCentral, especially tricky exams that focus on the English language rather than teaching you. I’m not a native speaker and this made me worry a little bit even though I have knowledge in SQL academically/professionally. I’m also familiar with web technologies. I took an undergrad MySQL course 4 years ago and remember seeing tricky questions but our exams were open book digitally or hard copy. I was able to get a good grade with studying regularly back then. Anyone has taken this class recently, what are your thoughts? Thanks in advance.

Hey there! I was thinking about designing a system... basically it keeps track of certain metrics like water usage. I was wanting to have a visualization dashboard that can show the overall usage over time with sorting (similar to Kibana) months, weeks, days, and hours. I was wondering how this would be fleshed out? I have some idea but I would love some help or ideas or feedback please! Thank you...

My thought:

I was thinking that since this is a small scale application with around 1000 users, possibly 1-10 visitors per day checking their dashboards. Even though it's small I would still like to give this system a scalable option as well in case it gets adopted (in theory).

So far what i have is that there would be that I would have a UI that then connects to a light weight load balancer like nginx (for future scalability), then have it connect to our backend API using some sort of HTTP polling that would pull in data every hour. Then we would have it connecting to a load balancer that would connect it to some sort of database and and cache. I would want to do a write-through cacheing for the first month of each user so that data pulls in automatically by default and when users log in to their dashboad the data can be pulled up easily.

I need some help fleshing out the database though, I was thinking possibly a relational database. Have a table for a user and a table for their water usage statistics but I am scared that type of data can be too big for a table. I am not really sure what database to use for this situation. Please help and please give some feedback! Thank you.

Just curious, I haven’t taken discrete but am choosing between these classes rn(On the waitlist for one)

Anyone have any good resources for monoisotopic mass libraries or databases? We just got a Waters LCMS system (QTOF) with MassLynx and i don't have any experience working with exact mass data. I'm struggling a little bit figuring out how to navigate what is my analyte and how exact my exact needs to be to confirm my analyte. Working mostly with small molecules (<1000Da). I'm a single quad GCMS user and this is my first adventure into LCMS. Thanks in advance!

An answer would be appreciated!

Figured I might as well spread the news like other guys have been doing with their respective exams, since a lot of people can't access the Teams chat this was announced in.

I thought I remember seeing that it did somewhere, but I can’t remember. In addition, is the class hard compared to most of the 2000s cs classes? Thanks so much!

Hey there, so I get this error after the installation of zabbix 5.0 on my Ubuntu 16.04 (xenial), the answers on the official zabbix forum for this error is vague, they said 'I fixed this error by editing /etc/zabbix/web/zabbix.conf.php or /etc/zabbix/zabbix_server.conf ' but they don't mention what they edited, and I already edited those files in the installation(fixed timezone and fixed DBname/DBuser/DBpassword).

thanks

[To all those who downvote just remember I'm simply asking for advice and resource material no need to act all high and mighty about it]

[Update: The project case is completely hypothetical, I do not intend on actually using this in the future, this is just a fun exercise to try and do. I also understand the importance of security especially in systems like these but I'm just a newbie and want to learn where to start IF I were to tackle something like this]

Hello,

I'm a complete noob when it comes to this type of stuff but I know a bit of C and C++, I also learned how to develop my own website through WordPress. But I know very little about servers and databases so please forgive me for any misconceptions or if I confused some terms.

I am trying to learn some database and software development skills/tools to help me with a small project. This is a completely hypothetical case I made to help me practice (as I was thinking of doing a similar project for a high-school monitoring system). This online website/webpage is meant to help students monitor their own progress in different subjects (math, physics, chemistry, etc.) based on teachers' inputs of grades at the end of each week (all teachers have their own username and password, but they have special admin permissions where they can modify grades and can view the grades of any student.)

Each student can login with a given username and password and examine his or her grades in different subjects (but of course they can only view not modify). Students can also view or download different excel graphs and data that represents or displays their progress. For example, bar charts that show the logged in student's overall standing in the class or in a particular subject. Graphs showing the student's improvement each week or month overall or in a particular subject. (assuming the student takes weekly exams on each subject)

Teachers or admins have access to the graphs/data of every student as well as access to more general data like male vs female performance. Highest overall average for the male or female student or highest scoring student in a particular subject.

The data collected from the students can be used by the school advisors. So if a student is failing in a particular subject they are sent an automatic email by the system and issued a warning. If they do not score above let's say 70 in that subject, then they are issued a second warning. After the third time an automated email is sent to the s

I’ve been researching the path on becoming a DBA and see a lot of conflicting texts and am not sure which one to follow. I also came across that some colleges prefer people who majored in information security and management of information systems, which seems like that would be taught in gender information systems, but I’m not actually sure.

My school offers a computer science major, but how do I know that they’ll teach me everything I need to become a DBA? Will they teach me SQL in computer science or would I have to take a separate programming / certification course to learn?

It seems like there are a lot of majors thrown around and recommended to take if you want to become a DBA, but what is the most viable option?

As a DBA, what other jobs could you get with the degrees that you have? Cyber security, help lines, what else is there if you wanted to have options open?

I’m currently 20 and recently left the trades as an electrician and am interested in starting this journey, it’s just been a bit confusing to me and any help would be appreciated. Thanks in advance

These are my options for classes

IT vs C.S

https://imgur.com/gallery/QjC6iXJ

So, I can choose to take Database Systems with either Sibel Adali (don't really know) or Kuzmin (had him for PSoft, he's okay)

Of course, none of you had to take it with both of them across two semesters, but which one sounds better? Can you tell me about your experiences with the course?

Also, I have a fairly good understanding of DB systems in general. In what ways can this course be useful with software engineering in general or at a workplace?

Hello,

We are 3rd-year college students and are currently working on our software engineering project. We are using NetBeans as the IDE for our project, which uses a JavaFX application that uses a derby client database on Java 8. We've already finished the application itself, and the problem is, we don't know how to deploy it locally so that the executable file would be able to run with the database.

Thank You for the answers

Myself and another developer made a centralized, extensible database system called HealthBox that allows users to store all of their health information in one, encrypted place, and grant programs access to it on a program by program basis. For developers, it's extremely easy to add and retrieve data programmatically, when compared to other health information systems like HealthKit.

The HealthBox system is entirely functional at the moment, but I'm looking to create some client side apps that use it, to help the ecosystem get off the ground. One of the things I was very interested in making is a nutrition tracker like Fooducate or MyFitnessPal, but completely freely licensed. However, to do this conveniently, I'd need a database of common foods to prevent users from having to enter every single nutrition statistic by hand. I was wondering if anyone knew of somewhere I could find a database like this, since it would make it drastically easier to create a program like this. It's critical that this database is freely licensed, since all of the software I create is entirely free from top to bottom, and I don't want to change that. However, I'm more than happy to pay for a database as long as I'm permitted to share it with my users.

Has anyone taken either of these classes and have a recommendation of which one I should take next semester alone with CS 0105? I’m guessing taking all three of those would be too much?

Trying to figure how I should design schema for handling payments. We have multiple payment method, refunds, transaction history.

My Plan so far:
1 - Have a table for Payments, which will contain all the common attributes (payer info, amount etc)
2 - Have Separate Tables for different payment methods (cash, cheque, credit card)
3 - A payment can have only 1 payment method.

Confused about how I should manage Refunds and Transaction History.

Any suggestion are welcome.

Regards.

I need to learn Databases, Operating Systems, Computer Science algorithms, Computer Networks, Computer Security, etc. Would I learn all those subjects at OSU Computer Science Postbaccalaureate?

I work as an analyst. I got my bachelor's degree in mathematics. I do not want to switch to a different field. However, I need to learn these subjects. Is this program a good idea? I can be admitted to a master's degree in computer science. However, I like more the idea of a bachelor's degree in computer science. What do you think?

I saw the OSU website before to post my question. I did not find in the curriculum computer security and computer networks.