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How do MySQL indexes work?
...index type is the B+Tree based index, that stores the elements in a sorted order. Also, you don't have to access the real table to get the indexed values, which makes your query return way faster.
The "problem" about this index type is that you have to query for the leftmost value to use the index....
What is the purpose of setting a key in data.table?
...set a key (e.g. X[Y] ). As such, I wish to understand what a key does in order to properly set keys in my data tables.
2 ...
How to recover stashed uncommitted changes
... index. Try without --index.
You're using git stash save --keep-index in order to test "what will be committed". This one is beyond the scope of this answer; see this other StackOverflow answer instead.
For complicated cases, I recommend starting in a "clean" working directory first, by committ...
Bitwise operation and usage
...the data type, Python simply expands the width to cater for extra bits. In order to get the discarding behaviour in Python, you can follow a left shift with a bitwise and such as in an 8-bit value shifting left four bits:
bits8 = (bits8 << 4) & 255
With that in mind, another example of ...
Throttling method calls to M requests in N seconds
...happen in big bursts by keeping the size M and delay N relatively small in order of handful millis. eg. M = 5, N = 20ms would provide a through put of 250/sec kepping burst to happen in size of 5.
– FUD
Sep 22 '12 at 10:51
...
Difference between EXISTS and IN in SQL?
... will tell you whether a query returned any results. e.g.:
SELECT *
FROM Orders o
WHERE EXISTS (
SELECT *
FROM Products p
WHERE p.ProductNumber = o.ProductNumber)
IN is used to compare one value to several, and can use literal values, like this:
SELECT *
FROM Orders
WHERE Produ...
Converting an array of objects to ActiveRecord::Relation
...ECT .... WHERE `my_models`.id IN (2, 3, 4, 6, ....
Keep in mind that the ordering of the array will be lost - But since your objective is only to run a class method on the collection of these objects, I assume it won't be a problem.
...
T-SQL split string
...elim, [Number]) - [Number])))
FROM (SELECT Number = ROW_NUMBER() OVER (ORDER BY name)
FROM sys.all_columns) AS x WHERE Number <= LEN(@List)
AND SUBSTRING(@Delim + @List, [Number], DATALENGTH(@Delim)/2) = @Delim
) AS y
);
GO
If you want to avoid the limitation of the length...
Schema for a multilanguage database
...GRP_Name_i18n_cust, GRP_Name_i18n, GRP_Name) AS GroupName
FROM T_Groups
ORDER BY GroupName COLLATE {#COLLATION}
E) Then, you can do this in your DAL:
cmd.CommandText = cmd.CommandText.Replace("{#COLLATION}", auth.user.language.collation)
Which will then give you this perfectly composed SQL-Q...
Error-Handling in Swift-Language
...or is not throwing at all.
2. Invoking function that may throw errors
In order to invoke function you need to use try keyword, like this
try summonDefaultDragon()
this line should normally be present do-catch block like this
do {
let dragon = try summonDefaultDragon()
} catch DragonError....