What is URL checking on verified URL list index?

There is an option Index check on:
(Default) is checking the domain.
This can be changed to another option, URL.
What is it for? Is this the same as the manual check that SER does to check if the site pointed to by the link is still active and has a backlink? (hmm .. no backlink would be needed, what if the link points to the money site, there is no link to THERE.) Just a bit confused …!

SQL Server – Can I delete an overlapping index if the larger index is unique?

I have 2 non-clustered indexes:

IX1 = (col1)
IX2 = (col1), (col2) (unique).

I want to delete the IX1 index because the optimizer can stop using IX2 for the first column and stop using it if that query is true, so performance should not be affected. But I had a tormenting thought in mind, it could be that the 2nd index can not be used if it is marked as unique.

both columns are integers, col1 is a FK

Unity 2D: ArgumentOutOfRangeException can not be resolved: The index was out of range

I'm a beginner in coding with no background information, so the code you see here may be terrible.

Basically, I make an endless runner, which consists of a player character and a series of obstacle prefabricated houses. The obstacle prefabs are provided with a trigger, so that when the player hits it, he creates the next prefab. I use the following code, and when the player presses the first spawn trigger, a prefab is generated, but on triggering the next trigger, I get the ArgumentOutOfRangeException error in the console and spawn nothing.

public class ObsTrigger: MonoBehaviour
{

 public GameObject spawnTrigger;
 (SerializeField) private List obstacleList;

 private void OnTriggerEnter2D(Collider2D other)
 {
     if (other.CompareTag("Player"))
     {
         for (int i = 0; i < obstacleList.Count; i++)
         {
             spawnObstacle();
         }
     }
 }

 public void spawnObstacle()
 {
     {
         Transform chosenLevelPart = obstacleList(Random.Range(0, obstacleList.Count -1));
         Instantiate(chosenLevelPart);
     }
 }

}

If someone can point me in the right direction, I would really appreciate it!

doxygen: qgarray :: at: absolute index xxxxxxxxxx out of bounds

I use Doxygen to parse the Linux kernel (https://github.com/torvalds/linux). After more than 20 hours, errors will be reported when generating the call diagrams: qgarray::at: absolute index xxxxxxxxxx out of range, I analyzed the source code and doubted it was due to the nature of it array_data->len in the doxygen-master/qtools/qgarray.h:54

struct array_data : public QShared {    // shared array
    array_data()    { data=0; len=0; }
    char *data;             // actual array data
    uint  len;
    };

I try one long Type for lenRebuild and reinstall Doxygen, but parsing Linux will take another 20 hours to validate.

I want to know how to fix the error perfectly.

Find the index of a sequence $ x_n $ close enough to its limit

Here is the question:

Define a sequence with $ x_0 $ and
$$
x_ {n + 1} = frac {x_ {n} ^ {2} +5 x_ {n} +4} {x_ {n} +6}.
$$

To let $ m $ be the least positive integer, so that
$$
x_ {m} leq 4+ frac {1} {2 ^ {20}},
$$

In which of the following intervals? $ m $ Lie?
$$
[9,26], [27,80], [81,242], [243,728], [729, + infty].
$$

I noticed that these intervals are powers of $ 3 $ So I'm considering a few approximations for $ x_n $, This sequence does not seem to have a general formula, so I'm struggling to find a formula that could approximate $ m $,

Is this the right way or is there better solutions to this problem?

Here is the plot of the sequence.
Enter image description here

postgresql – What makes a large single index size (except bloat?)

I did a bit of work on the size of our PostgreSQL 9.6 production database and found some results that I found surprising.

We have a table (let's call it foos) with about 10 million records, The primary key is one integer, We have a B-tree index for this table for an optional foreign key in another table (let's call it bars). Let's call the index index_foos_on_bar_id, bars.id is only one integer Data Type column.

If I look at the index size with that di+ meta command I see that it is occupied somewhere in the neighborhood of 1 GB Room. A bit of math on the back of the envelope would mean that every entry in the index needs about 1 GB / 10 million = 100 bytes of memory per line,

There is almost no deletion on the Internet foos Table, the upswing is absent.

In my opinion, an index would contain something like sorted pairs of numbers that map the indexed column to the primary key of the relevant table. There it is only integer Types that would only use about 4 + 4 = 8 bytes per lineThis is far from the 100 bytes per line that are actually occupied. I think the fact that it is a tree structure could easily increase that, but the over 10x difference was a bit of an eyebrow pull up for me.

What is the point that all "extra" space is used by the index?

Security – Is there an index / statistic that reflects the likelihood of theft in a particular country?

The likelihood of items being stolen varies greatly from country to country. For example, leaving my phone unattended in an underground station for an hour would be expected to be stolen while in Paris, while in Tokyo it is nearly impossible to be stolen. For the same reason pickpocketing in Athens is a tourist experience, while in Seoul it is virtually unknown.

Is there an index / statistics / etc reflecting the likelihood that items will be stolen in a given country? That would help me adjust my expectations appropriately and how careful I should be with my stuff. Ideally, I would like to have a list of countries along with the amount of theft probability.