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What database does Google use?
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Bigtable
A Distributed Storage System for Structured Data
Bigtable is a distributed storage
system (built by Google) for managing structured data
that is designed to scale to a very
large size: petabytes of data acros...
Bash empty array expansion with `set -u`
...-} or ${arr[@]:0}, are not safe across all major versions of Bash.
As the table below shows, the only expansion that is reliable across all modern-ish Bash versions is ${arr[@]+"${arr[@]}"} (column +"). Of note, several other expansions fail in Bash 4.2, including (unfortunately) the shorter ${arr[...
Select top 10 records for each category
.... Can anyone help with how to do it? Section is one of the columns in the table.
14 Answers
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How to assign an exec result to a sql variable?
...that is returned, you can do the same for all other kinds (didn't check if table possible, but I think yes.) I just tried it for nvarchar(50).
– Mzn
May 18 '14 at 4:39
2
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What are the differences between “=” and “
...expression). In fact, ?Syntax in R gives the following operator precedence table, from highest to lowest:
…
‘-> ->>’ rightwards assignment
‘<- <<-’ assignment (right to left)
‘=’ assignment (right to left)
…
But is this the on...
How to write a foreach in SQL Server?
...rforms better than a cursor and is simpler:
DECLARE @PractitionerList TABLE(PracticionerID INT)
DECLARE @PractitionerID INT
INSERT @PractitionerList(PracticionerID)
SELECT PracticionerID
FROM Practitioner
WHILE(1 = 1)
BEGIN
SET @PracticionerID = NULL
S...
Can a foreign key be NULL and/or duplicate?
...mply requires that the value in that field must exist first in a different table (the parent table). That is all an FK is by definition. Null by definition is not a value. Null means that we do not yet know what the value is.
Let me give you a real life example. Suppose you have a database that sto...
What's the difference between echo, print, and print_r in PHP?
...ing
No return value
var_export()
Outputs a human-readable and PHP-executable representation of any one value
Accepts not just strings but other types including arrays and objects, formatting them to be readable
Uses a different output format to both print_r() and var_dump() - resulting output is...
Saving changes after table edit in SQL Server Management Studio
If I want to save any changes in a table, previously saved in SQL Server Management Studio (no data in table present) I get an error message:
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How to center a checkbox in a table cell?
... contains nothing but a checkbox. It is rather wide because of text in the table header row. How do I center the checkbox (with inline CSS in my HTML? (I know))
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