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.NET unique object identifier
...e cost, but such a thing could be helpful if one compares two distinct immutable objects and finds them equal; if one when possible overwrites the reference to the newer one with a reference to the older one, one can avoid having many redundant references to identical but distinct objects.
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How can I clear the SQL Server query cache?
... (OPTIMIZE FOR UNKNOWN)
Then your query will be like this
select * from Table where Col = 'someval' OPTION (OPTIMIZE FOR UNKNOWN)
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What does the [Flags] Enum Attribute mean in C#?
...ean, I prefer to have the full int in source code. If I have a column on a table in the database called MyEnum that stores a value of one of the enums, and a record has 131,072, I would need to get out my calculator to figure out that that corresponds to the enum with the value 1<<17. As oppos...
Rails find record with zero has_many records associated [duplicate]
... do includes it does a join. In a SQL join, you get all the fields of both tables (in this case cities and photos) for each row unless you change the projection of the query. So, he's using that to his advantage to check whether a required database identifier is present. If it's not, then there was ...
How to check if a variable is set in Bash?
... This answer is very confusing. Any practical examples on how to use this table?
– Ben Davis
Sep 27 '14 at 17:16
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In C++, is it still bad practice to return a vector from a function?
... as vectors/arrays—in many programming languages. Is this style now acceptable in C++0x if the class has a move constructor, or do C++ programmers consider it weird/ugly/abomination?
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source of historical stock data [closed]
...n reverse engineer the following example:
http://ichart.finance.yahoo.com/table.csv?s=YHOO&d=0&e=28&f=2010&g=d&a=3&b=12&c=1996&ignore=.csv
Essentially:
sn = TICKER
a = fromMonth-1
b = fromDay (two digits)
c = fromYear
d = toMonth-1
e = toDay (two digits)
f = toYear...
SQL Server: Get data for only the past year
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This will have very bad performance on big tables, you query will loop over every record to evaluate the year value of the date, it would be better to use a date range
– Adriaan Davel
May 30 '12 at 15:43
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How can I verify if one list is a subset of another?
...ists be the same for many tests? It does as one of them is a static lookup table 2.Does it need to be a list? It does not - the static lookup table can be anything that performs best. The dynamic one is a dict from which we extract the keys to perform a static lookup on. Will this fact alter the so...
grep using a character vector with multiple patterns
...attern = 'A1|A9|A6', x = myfile$Letter)
Or even more simply:
library(data.table)
myfile$Letter %like% 'A1|A9|A6'
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