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Remove Links Question

Hi guys!
I want to remove all links ( near to 300 ) on one
of my projects. I set it to “Active(Remove LInks) some days ago, but
nothing happens.
Is that option working, or is there any other
option to remove links from a project?


reactjs – (PERN Stack) Question regarding the storage of data (with Apollo client/server)

I’m having some kind of a struggle.
I’m building an using the spacex api, i use the graphql endpoint to fetch my data: https://spacexdata.herokuapp.com/graphql

From there, the data is generated with graphql code generator and is strictly on the client side, it doesn’t interact with the server side where my user db is.

I have a user entity that looks like so:

import { Field, Int, ObjectType } from "type-graphql";
import { BaseEntity, Column, CreateDateColumn, Entity, PrimaryGeneratedColumn, UpdateDateColumn } from "typeorm";

export class User extends BaseEntity {

    @Field(() => Int)
    id: number

    @Column({unique: true})
    username: string

    @Column({unique: true})
    email: string

    password: string

    @Field(() => String, {nullable: true})
    @Column({nullable: true})
    avatar?: string

    @Field(() => String, {nullable: true})
    @Column({nullable: true})
    first_name?: string

    @Field(() => String, {nullable: true})
    @Column({nullable: true})
    last_name?: string

    @Field(() => String)
    created_at: Date

    @Field(() => String)
    updated_at: Date

I’d like, when the user is logged in (i got that part covered aswell), to be able to bookmarks flight from the spacex api and i’m not sure how to proceed.

My questions are the following:

  1. Should I store the flight in a separate entity and do relationship with the user entity ?
  2. Should I create a new variable of type (Flight) that point to a separate class (that isn’t necessary an entity, just a model class) ?
  3. Should I store the bookmarks flight in the client side ?

Thank you !

set theory – A question regarding the “math tea” argument

Joel David Hamkins published a paper where he analyzes the “math tea” argument, namely, the argument that some real numbers are undefinable. He constructed a countable model of set theory where all sets are definable without parameters, and this apparently shows the flaw with the math tea argument. However, I still think some real numbers are undefinable. Here is why. Since we know that, “in the real universe”, the real numbers are uncountable, they can’t fit inside a countable model $M$, even if $M$ thinks the set of reals in that model are internally uncountable. So, basically, I think any countable model of set theory will never have all of the “real” real numbers, and this is why I think some real numbers are undefinable. I would like some clarification of this, and want to be corrected if I misunderstand something.

multitenancy – Design question for handling large volumes of messages in multi-tenant queue

I have a system with two applications interacting via a message queue. Let’s call them Producer and Consumer. Some key context is that this a multi-tenancy scenario.

Producer produces events based on various inputs (user interactions, api, etc…) and Consumer does down stream processing on these. One of our key constraints is that Consumer can only process events one-at-a-time-per-tenant.

Our current solution (a bit naive) is that multiple worker threads are pulling from the queue and processing events, and if a tenant has another event in progress later worker thread(s) just waits. This has been fine for a couple years given our thread pools and typical event production patterns, but we had a scenario where thousands of events for a single tenant were generated in Producer, and all of Consumer’s worker threads except one were stuck waiting. Consumer was therefore processing events from the queue one at a time, and our “eventual consistency” lag time became suboptimal.

We’ve got some candidate ideas for managing this:

  1. Load balancing across queues – new messages go to the most empty queue, but tenants are locked to a single queue (how we achieve this exactly TBD)
  2. Create a “slow lane” queue – if during processing of an event, the tenant is already in use, move the events to the “slow lane”. This will drain the primary queue quickly but has implications for event processing idempotency I’m not sure will be valid for our scenario.

Before we start digging on these options and looking for others, I’m curious if anyone here has experience with patterns for dealing with this type of situation.

Appreciate any info/advice/guidance. Thanks!!

Question about my IP

So my friend sent me a IP grabbing link. I copied and pasted into playstation messages and sent it to my cousin. I’m wondering if my friend got my IP because I copied and pasted. I didn’t open the link nor click it so am I safe?

calculus – Question about Integrability definition using Partitions of Unity

On page 65 of Spivak’s Calculus on Manifolds, when defining the integral of an (potentially unbounded) $f$ on an (potentially unbounded) set $A$, there is a theorem, which states:

If $A$ is Jordan-measurable and $f$ is bounded, then this definition
of $int_A f$ agrees with the old one.

Note that “this definition” refers to $int_A f = sumlimits_{phi in Phi} phi cdot f$, where $Phi$ is a partition of unity for some admissable open cover of $A$. The “old definition” refers to the integral defined on a bounded set and a bounded $f$ on this set, using $U(f,P)$ and $L(f,P)$.

$A$ is not stated to be bounded in this theorem. Is this just an omission, or does this follow from $A$ being Jordan-measurable?

attacks – Question on stack overflow

I am preparing for an exam in Computer Security and doing a past-exam without soluions, so I wanted to check if my reasoning holds on a question about stack overflow. Below is the C code in question. The goal is to make the function do_something() execute, no matter if pwd is “abcd” or “1234”.

My thought is to overflow the variable usertype inside the init() function. Firstly, am I correct in that the stack during the execution of this function would look like:

                   |Return Address  |
                   |Frame Pointer   |
                   |usertype        |

and if so, if an attacker inputs a usertype that floods into Frame Pointer and overwrites the Return Address with the address of do_something(), we achieve what is asked for in the question?

Thank you in advance!

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postgresql – First question on here: what would be the best database for this set of environmental data?

Thanks for being out here. For educational purposes I want to create a website that queries a database of rising temperatures across the globe. The data can be seen here in an .xlsx format: Climate-Impact-Lab_Global-Data

Bear in mind that my knowledge of data structing is at a beginner level. Does a cloud-hosted noSQL database make sense? Should I create my own database? Would MongoDB make more sense? How do you determine this?

The website is created with the React framework and ultimately just wants to let users query the database. Users should be able to query their country and get a result of the temperature around the mid-century 2040-2059 or 2080-2099. For authentication purposes, I use Google Cloud Firestore to store user information. Hence I thought it made sense to use the Google Firebase Realtime Database. Yet when I imported the JSON into firebase, the data wasn’t structured properly anymore. Also, I wonder if this is overkill. Thus, I think I should reconsider my options from the beginning.

What would you be the best practice here? If this is not the proper way to ask questions on dba.stackexchange, I would appreciate it if you can recommend an alternative method. Also, once I succeed to create the web app, I will surely let you know :]

Thank you for the help.