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What is the difference between substr and substring?
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10 Answers
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Try-finally block prevents StackOverflowError
...vel into the finally block take twice as long an the stack depth could be
10,000 or more. If you can make 10,000,000 calls per second, this will take 10^3003 seconds or longer than the age of the universe.
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MySQL JOIN the most recent row only?
... CONCAT(title, ' ', forename, ' ', surname) LIKE '%Smith%'
LIMIT 10, 20;
Note that a JOIN is just a synonym for INNER JOIN.
Test case:
CREATE TABLE customer (customer_id int);
CREATE TABLE customer_data (
id int,
customer_id int,
title varchar(10),
forename varchar(10),
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Apache Spark: The number of cores vs. the number of executors
... and
yarn.nodemanager.resource.cpu-vcores, should probably be set to 63 *
1024 = 64512 (megabytes) and 15 respectively. We avoid allocating 100%
of the resources to YARN containers because the node needs some
resources to run the OS and Hadoop daemons. In this case, we leave a
gigabyte and a core fo...
Which is more efficient, a for-each loop, or an iterator?
...derwater.
If however, you mean by loop the old "c-style" loop:
for(int i=0; i<list.size(); i++) {
Object o = list.get(i);
}
Then the new for loop, or iterator, can be a lot more efficient, depending on the underlying data structure. The reason for this is that for some data structures, get...
SQLite add Primary Key
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answered Jun 3 '09 at 17:42
Nathan RidleyNathan Ridley
31.2k2828 gold badges113113 silver badges186186 bronze badges
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Set keyboard caret position in html textbox
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208
Excerpted from Josh Stodola's Setting keyboard caret Position in a Textbox or TextArea with Jav...
MySQL: Enable LOAD DATA LOCAL INFILE
...red to permit it. For example, if mysqld was started with
--local-infile=0, LOCAL does not work. See Section 6.1.6, “Security Issues with LOAD DATA LOCAL”.
You should set the option:
local-infile=1
into your [mysql] entry of my.cnf file or call mysql client with the --local-infile option:...
Retrieving the text of the selected in element
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260
function getSelectedText(elementId) {
var elt = document.getElementById(elementId);
if ...
PHP script - detect whether running under linux or Windows?
...sible Values For: PHP_OS and php_unameDocs:
if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
echo 'This is a server using Windows!';
} else {
echo 'This is a server not using Windows!';
}
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