magento2 – What is the difference between user defined and system defined client attribute properties and what are they used for?

How to create a client attribute is explained in various responses such as this or that. What they all have in common is that when creating the attribute, its properties user_defined and system are always defined like this:

'user_defined' => true,
'system' => false,

For me, it doesn't work. When you set the properties as shown above, the attribute is not visible in the adminhtml client modification form. When adjusting user_defined => false and system => true it is displayed but now saved. This only works (display in form and record) when both properties are set to false.

So my question is what is the difference between the two properties and what are they for?

Time difference on the phone while sending SMS

My boyfriend is in Russia and I am in the United States when I texted him, the time is here on my phone and he texted me from Russia, the time will be reflected in my phone or just my time

unit – Initialization of variables, difference between waking up and initializing in class

public class ExampleClass: MonoBehaviour  
   int exampleVariable = 0;  
   int exampleVariableForAwake;  
   void Awake()
      exampleVariableForAwake = 0;  

What is the difference between initializing a variable at declaration against. initilize in Awake?
What I understand should be used in place of constructors in Unity C #, welcome to correct me if I'm wrong.

What use is considered an appropriate convention by the community, if any?

The same question could also be Properties, so I'm going to leave that open.

Message Queue – Difference Between AMPS and AMQP

I recently crossed an acronym AMPS (Asyncronous Message Processing System (by 60EastTechnologies. As this is not a standard like AMQP (Asynchronous Message Queuing Protocol) or JMS (Java Messaging System) and Kafka being an ecosystem of flow processing, I'd like to know where AMPS stands out.

What I know AMQP encapsulates "Smart broker, dumb broker" and Kafka encapsulates "Smart broker, dumb broker". Where is AMPS located? Their website says it is "unmatched scalability" and a "state of the world cache".

It appears to be just a redesign of the AMQP, but it is owned and used in financial institutions such as Morgan Stanley. I would like to know when and where to use AMPS.

dnd 3.5e – Is there a difference between confirming a critical hit and making a critical hit in 3.5?

For this question and my answer, is there a mention somewhere in the rules, maybe in the FAQ? because in PF it is confirmed that it is the same here.

Scoring VS Confirmation, are they identical or not in 3.5? (it is confirmed in PF that it is the same thing)

Because you can use the critical flaming burst ability on a creature immune to critical hits, as shown here.

But you don't do critical base damage. Blood in the water might not work if confirmation of actual critical hit (which means you verify that you would normally do so if done on a creature not immune to critical hit, activating the critical ignited burst ability) 39; is not the same as the term & quot; scoring & # 39; & # 39; which could actually mean that you have to do additional damage to Blood in the water activate.

I think both terms mean the same thing as in PF, but I wanted a rule reference or a quote from FAQ, etc.

sql – What is really the difference between relational and non-relational data?

Here's where I'm at right now: I know that relational data, like that found in relational databases like MySQL or Postgres, is relational because there are relationships between tables. This is the reason why RDBMSs have rigid patterns. On the other hand, NoSQL databases offer a looser schema but lose these relationships. But MongoDB, for example, offers official support (or at least blog posts) for associations between data (one to one, one to many, etc.).

Now, I really don't know if the data I'm going to have in a project is relational and therefore if MongoDB would be a bad choice. People keep mentioning that you shouldn't use NoSQL databases unless specific reason to use them on a traditional RDBMS. But I really like MongoDB, especially for GraphQL. Working in JavaScript, I love working with Mongoose.
My data structure, on the other hand, seems rather relational (the users have machines, the machines are inside the rooms, which also belong to the users).

I'm really confused. Everyone keeps talking about the MERN / MEVN / MEAN stack and how awesome MongoDB is with Node, which I agree and love, but sometimes people tend to jump in too much the hype. Can you give me your opinion on this one?

functional analysis – semigroups and Markov resolvers, difference in continuity

Let $ (E, d) $ be a locally compact separable metric space. We have a Markov process $ X = ( {X_t } _ {t ge 0}, {P_x } _ {x in E}) $ sure $ E $. For a limited measurable function $ f $ sure $ E $, we define
begin {align *}
P_tf (x) & = E_ {x} (f (X_t)), quad t> 0, \
R _ { alpha} f (x) & = int_ {0} ^ { infty} exp (- alpha t) P_tf (x) , dt, quad alpha> 0.
end {align *}

We assume that for any bounded measurable function $ f colon E à mathbb {R} $ and $ alpha> 0 $, function $ R _ { alpha} f $ East $ lambda $-Hölder continuous function activated $ (E, d) $. In other words, he contends that
begin {align *}
| R _ { alpha} f (x) -R _ { alpha} f (y) | le Cd (x, y) ^ { lambda}, quad x, y in E,
end {align *}

or $ lambda> 0 $ and C $> $ 0 are a positive constant independent of $ x, y $.

My question

We assume that the Markov process $ X $ is symmetrical with respect to a $ sigma $– finished measurement $ m $.
Under the above conditions, the semi-group $ P_tf (x) $ is also Hölder continues in $ x $?

If the semi-group is ultracontractive in the sense that $ P_t (L ^ 1 (E, m)) subset L ^ { infty} (E, m) $, for all $ t> 0 $ and $ f in L ^ 2 (E, m) $, we can find a bounded measurable function $ h colon E at mathbb {R} $ such as $ P_tf = R_ {1} h $. Without the ultracontractivity, can we prove the Hölder continuity of $ P_tf $?

optical – What is the difference between a pentaprism and a pentamirror?

The fundamental difference is that a pentaprism is a block of solid glass. That means it is quite heavy. It has mirror material on all but two sides, so that light enters on one side, is reflected around the interior, and then comes out on the other side not mirror. This means that there are only 2 air / glass interfaces involved: one where the light enters the prism, and one where it leaves the prism. This minimizes light loss.

A pentamiroir does pretty much the same thing, but it is made up of a number of separate mirrors, so there is air in the middle instead of a block of solid glass. This makes it considerably lighter and less expensive. It also means that there is an air / glass interface for each individual mirror, so there is a bit more light loss.

As a result, a pentamirror is used almost exclusively in relatively low-end cameras where cost and weight are more important than a relatively dark view through the viewfinder.

What is the difference between events sent by the server and Websockets in html5?

What are the main differences between events sent by the server and WebSockets?

What are the uses of events sent by the server?

Help me find out !!

Thank you!!

Web API – What are libraries or tools for determining the difference between API calls?

I am building an integration for an API that only makes CRUD requests, it does not inform us of changes via a callback.

From this, I want the data updates. Just the updates thank you. Preferably in the form of json messages to queue.

There must be services or libraries that determine these updates for me and trigger them in a queue.