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Is there a performance difference between i++ and ++i in C++?
...it, even if you are not right now.
Knuth.
Premature optimization is the root of all evil. As is premature pessimization.
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Tricks to manage the available memory in an R session
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I make aggressive use of the subset parameter with selection of only the required variables when passing dataframes to the data= argument of regression functions. It does result in some errors if I forget to add variables to both the formula and the select= vector, but it sti...
Can I run multiple versions of Google Chrome on the same machine? (Mac or Windows)
...file dialog appears (or: Drag & drop the chrome installer on the VBS). Select the destination of the Chrome installer, and the script automatically unpacks the files and duplicates the profile from a pre-configured base directory.
By default:
The Chrome binaries are placed in subfolders of C:...
Automatically create an Enum based on values in a database lookup table?
... | 2 | Yellow |
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Construct a select to get the values you need:
select * from enums e inner join enum_values ev on ev.enums_id=e.id where e.id=0
Construct the source code for the enum and you'll get something like:
String enumSourceCode = "enum " + e...
How to check if a function exists on a SQL database
...hat SSMS uses when you script using the DROP and CREATE option
IF EXISTS (SELECT *
FROM sys.objects
WHERE object_id = OBJECT_ID(N'[dbo].[foo]')
AND type IN ( N'FN', N'IF', N'TF', N'FS', N'FT' ))
DROP FUNCTION [dbo].[foo]
GO
This approach to deploying...
What is the difference between bindParam and bindValue?
...iated parameter markers
Example:
$value = 'foo';
$s = $dbh->prepare('SELECT name FROM bar WHERE baz = :baz');
$s->bindParam(':baz', $value); // use bindParam to bind the variable
$value = 'foobarbaz';
$s->execute(); // executed with WHERE baz = 'foobarbaz'
or
$value = 'foo';
$s = $dbh...
Linux: is there a read or recv from socket with timeout?
How can I try to read data from socket with timeout?
I know, select, pselect, poll, has a timeout field, but using of them disables "tcp fast-path" in tcp reno stack.
...
Undo part of unstaged changes in git
...ier if you use a good editor mode or plugin, which may provide support for selecting lines directly to revert, as -p can be a bit clumsy to use sometimes. I use Magit, an Emacs mode that is very helpful for working with Git. In Magit, you can run magit-status, find the diffs for the changes that you...
Difference between partition key, composite key and clustering key in Cassandra?
...KEY:
insert into stackoverflow_simple (key, data) VALUES ('han', 'solo');
select * from stackoverflow_simple where key='han';
table content
key | data
----+------
han | solo
COMPOSITE/COMPOUND KEY can retrieve "wide rows" (i.e. you can query by just the partition key, even if you have clusteri...
Error “The connection to adb is down, and a severe error has occurred.”
... I solved my issue. I go to Task Manager in windows7 -> processes -> selected the adb.exe -> End Process. After that I go to cmd prompt and type adb start-server. This time adb statred succefully. I run eclipe and it was showing no error.
– Nishant
Apr...