postgresql – Select list of attributes that exist in all groups

select distinct(p) from Pub;
select * from field limit 20;

pub and field join on column k (primary key)

I want to write a query that returns only those attributes (author/journal/year etc.) that have at least one record in every publication type: phdthesis, book, etc.

Google Groups “Spam message handling” Setting Won’t Stay Set

I have a free Google Groups group setup and messages (which are being forwarded from a Gmail account) keep going into the Pending moderation queue. I’ve repeatedly attempted to change the “Spam message handling” setting (only visible when you click “Advanced settings”) to “Post suspicious messages to the group”, but every time I refresh the settings page it’s reverted back to “Moderate and notify content moderators”.

Is there a way to actually change this setting and allow these messages through?

algebraic topology – Free Groups – representation of 1 by empty word is unique

I am studying Free Products of Groups from Munkres’ Topology book. The definition of free products is:

Let $G$ group, ${G_a}_{a in J}$ family of groups that generates $G$ and $G_a cap G_b$ consists of the idenity element alone whenever $a neq b$.
We say that $G$ is the free product of $G_a$, if for each $x in G$ there is only one reduced word that represents $x$.

After that it says and proves, that it suffices to know that the representation of $1$ by the empty word is unique.

What does exactly the latter means?
Isn’t the empty word unique and doesn’t always represents $1$?
By the previous argument it looks to me like the condition of the uniqueness of the reduced word to be redundant.

How to add "Tags" in Facebook Groups Settings?

Hello all. Short while back I had created a few fb Groups and made them Public. One problem is not every group has the "Tag" option in Settings so I don't know how I can add tags, any options for this please?

First Responder Kit and Availability Groups

Is there anything in the First Responder Kit that deals specifically with Availability Group issues? Is there anything new developing?


availability groups – What is the fastest way to make a copy of a 5TB SQL Server DB on the same server without having to fully reinitialize the DB to add it to the AG

I have a 3 node Always On AG that hosts a 5TB database. Due to business requirements, at 12:01am on the first day of every month, I need to create a copy of that database on the 3rd node (replica) appended with the previous month name. For example, on April 1st, I create a DB called “mydatabase_march2021” which is a copy of “mydatabase” current as of April 1st at 12:01am.

My current process involves removing the DB from the AG on the 3rd node promptly at 12:01am, renaming it, and then starting the slow process of backing up and restoring the 5TB DB to the 3rd node and adding it to the AG. Is there some other way I can do this without having to fully reinitialize the DB on the 3rd node? I need to have this copy available to business users by 5am.

I have tried removing the DB from the AG, offlining SQL, making a copy of the DB files, but there is no way to attach those files and keep the DB in recovering (which is necessary to reinitialize).

Additional Information:
Windows Server 2016 Standard
SQL Server 2012 SP4 Enterprise (will be upgrading to SQL 2016 or 2019 at some point in the next year)
Node 1 is in datacenter A
Node 2 and Node 3 are in datacenter B

active directory – Get list of AD groups a user is a primary owner of

i would like to get list of AD groups a user is a primary owner of.
i have gone through this question already. But its not giving me the attribute/property whether the user is a primary owner of secondary owner.

How to get the above requirement. the below code is for getting the memberonly. ( Please correct me , if i am wrong)

Import-Module ActiveDirectory
(Get-ADUser userName –Properties MemberOf | Select-Object MemberOf).MemberOf

sets – Disjoint groups using maximum matching

In the 3-Path Packing problem, we are given an undirected graph $G$ and a parameter
$k in mathbb{N} cup {0}$. We need to answer YesNo if there exists a collection of $k$ vertex disjoint paths on three vertices in $G$.

I am interested in an easier variant of this problem where we are given an additional group $M subseteq V$ that the middle vertex in each path is from $M$ and the adjacent nodes are not. So for any legal 3-path $urightarrow v rightarrow x$ : $u,x in V setminus M$ and $v in M$.

I am trying to find a polynomial algorithm for this problem by using maximum matching.

My solution is based on defining a vertex for any possible 3-path in the graph.
Since we are restricting ourselves to choose a middle vertex only from $M subseteq V$ this can be done in polynomial time and space.

I am now trying to define the edges and extra nodes in a manner that will guarantee that nodes with common vertexes can not be picked together. But every time I am blocking or allowing legalilligal choices.

This problem can be also represented as determining if there exist $k$ disjoint sets among a given group in size 3.

Any suggestions?

availability groups – The Windows Server Failover Clustering (WSFC) resource control API returned error code 19

Here are the details of that error code (19):


19 (0x13)

The media is write protected.

You need to consult the cluster log (use Get-ClusterLog to get that) for additional details about what writes failed within the cluster operation being performed. Check that out and update your question with any errors you see.

That being said, combined with this symptom:

…if you reboot second node, database wont up.

You might be experiencing disk problems. Check the Windows system event log and SQL Server error log for messages related to failed writes or corruption.

lie algebras – Exponential map generates the identity component of closed linear groups

In page 15 of “Lie groups beyond an introduction” by Prof. Knapp, Corollary 0.20 states that the exponential map (of linear Lie algebra $mathfrak g$) generates the identity component $G_0$ of a closed linear group $G$. The proof goes like

1 by continuity of the exponential map $exp(mathfrak g)$ is connected

2 $exp(mathfrak g)$ contains a neighborhood of 1 in the group (local diffeomorphism)

3 the smallest subgroup containing a nonempty open set in $G_0$ must be $G_0$

3 doesn’t look obvious to me though, I don’t know how to prove that $exp(mathfrak g)$ is a subgroup. In addition, if we can show it’s open, then it’s an open closed connected subgroup, so it must be $G_0$ since $G_0$ is connected.