大约有 48,000 项符合查询结果（耗时：0.0646秒） [XML]
Why is Magento so slow? [closed]
...g, layout config, etc.) that involve building up giant XML trees in memory and then "querying" those same trees for information. This takes both memory (storing the trees) and CPU (parsing the trees). Some of these (especially the layout tree) are huge. Also, unless caching is on, these tree are ...
mongodb group values by multiple fields
...takes an "pipeline" expression as an argument instead of the "localFields" and "foreignFields" options. This then allows a "self-join" with another pipeline expression, in which we can apply $limit in order to return the "top-n" results.
db.books.aggregate([
{ "$group": {
"_id": "$addr",
"...
Why malloc+memset is slower than calloc?
...se it can skip memset() entirely. In other cases, calloc() can even cheat and not allocate any memory! However, malloc()+memset() will always do the full amount of work.
Understanding this requires a short tour of the memory system.
Quick tour of memory
There are four main parts here: your prog...
Configure Flask dev server to be visible across the network
... To set to a specific ip app.run(host="192.168.1.7",port=5010) handy if your pc has a few ip's
– lxx
Jan 2 '15 at 3:29
2
...
Convert date to datetime in Python
...at it does is first retrieving the minimum value representable by datetime and then getting its time component. Incidentally, datetime.min = datetime(MINYEAR, 1, 1, tzinfo=None) and has a time of 00:00:00. However, I think it is cleaner to explicitly create a 00:00:00 time either through time.min or...
HtmlSpecialChars equivalent in Javascript?
Apparently, this is harder to find than I thought it would be. And it even is so simple...
16 Answers
...
Rails has_and_belongs_to_many migration
I have two models restaurant and user that I want to perform a has_and_belongs_to_many relationship.
4 Answers
...
How to SSH to a VirtualBox guest externally through a host? [closed]
... one interface already which is using NAT. Then go to the Network settings and click the Port Forwarding button. Add a new Rule. As the rule name, insert "ssh". As "Host port", insert 3022. As "Guest port", insert 22. Everything else of the rule can be left blank.
or from the command line
VBoxMan...
Understanding the Gemfile.lock file
After running the bundle install command, 'Gemfile.lock ' is created in the working directory. What do the directives inside that file mean?
...
Numeric for loop in Django templates
... a simple technique that works nicely for small cases with no special tags and no additional context. Sometimes this comes in handy
{% for i in '0123456789'|make_list %}
{{ forloop.counter }}
{% endfor %}
share
...