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Why is iterating through a large Django QuerySet consuming massive amounts of memory?
...rst time you iterate over it. For example, this will print the headline of all entries in the database:
for e in Entry.objects.all():
print e.headline
So your ten million rows are retrieved, all at once, when you first enter that loop and get the iterating form of the queryset. The wait ...
Select unique or distinct values from a list in UNIX shell script
...n the following input:
class
jar
jar
jar
bin
bin
java
uniq will output all lines exactly once:
class
jar
bin
java
uniq -d will output all lines that appear more than once, and it will print them once:
jar
bin
uniq -u will output all lines that appear exactly once, and it will print them ...
What can , and be used for?
...iewParam name="id" value="#{bean.id}" />
</f:metadata>
does basically the following:
Get the request parameter value by name id.
Convert and validate it if necessary (you can use required, validator and converter attributes and nest a <f:converter> and <f:validator> in it like...
Standard concise way to copy a file in Java?
...
As toolkit mentions above, Apache Commons IO is the way to go, specifically FileUtils.copyFile(); it handles all the heavy lifting for you.
And as a postscript, note that recent versions of FileUtils (such as the 2.0.1 release) have added the use of NIO for copying files; NIO can significantly ...
How to get the full path of running process?
...
According to my measurements, calling process.Modules[0] is 50 times slower than calling process.MainModule.
– Luca Cremonesi
Oct 23 '14 at 16:14
...
ios app maximum memory budget
...ered your own question: try not to go beyond the 70 Mb limit, however it really depends on many things: what iOS version you're using (not SDK), how many applications running in background, what exact memory you're using etc.
Just avoid the instant memory splashes (e.g. you're using 40 Mb of RAM, a...
Difference between string and text in rails?
...ng it as a singular char t. I migrated a column without realizing this and all future rows where the value is true is now t. Does anyone have any insights into this behaviour?
– Peter
Aug 11 '15 at 18:25
...
How do I install an R package from source?
...nt me along this great tutorial on webscraping NYtimes with R . I would really love to try it. However, the first step is to installed a package called RJSONIO from source.
...
Multiple Updates in MySQL
...has new records then i will end up inserting only the ids and count except all other information. if and only if there is an entry for the id then it should update else it should skip. what shall i do?
– Jayapal Chandran
Aug 30 '10 at 13:30
...
Difference between RegisterStartupScript and RegisterClientScriptBlock?
...:
a. When you use RegisterStartupScript, it will render your script after all the elements in the page (right before the form's end tag). This enables the script to call or reference page elements without the possibility of it not finding them in the Page's DOM.
Here is the rendered source of the ...