大约有 44,621 项符合查询结果（耗时：0.0422秒） [XML]
When and why are database joins expensive?
I'm doing some research into databases and I'm looking at some limitations of relational DBs.
7 Answers
...
Is there any kind of hash code function in JavaScript?
...bjects, a set. I had the brilliant idea of just using a JavaScript object with objects for the property names. Such as,
20 ...
What are the First and Second Level caches in Hibernate?
...
1.1) First-level cache
First-level cache always Associates with the Session object. Hibernate uses this cache by default. Here, it processes one
transaction after another one, means wont process one transaction many
times. Mainly it reduces the number of SQL queries it needs to
...
How to print out a variable in makefile
...file, I have a variable 'NDK_PROJECT_PATH', my question is how can I print it out when it compiles?
15 Answers
...
What is the purpose of a self executing function in javascript?
...
It's all about variable scoping. Variables declared in the self executing function are, by default, only available to code within the self executing function. This allows code to be written without concern of how variables ar...
What uses are there for “placement new”?
Has anyone here ever used C++'s "placement new"? If so, what for? It looks to me like it would only be useful on memory-mapped hardware.
...
PHP expects T_PAAMAYIM_NEKUDOTAYIM?
...
It’s the double colon operator :: (see list of parser tokens).
share
|
improve this answer
|
foll...
Easy way to prevent Heroku idling?
... free apps the dynos seem to keep idling - my app has very low traffic but it's also not really acceptable in my case that my users have to wait 20+ seconds to spin up a new dyno.
...
Websocket API to replace REST API?
...
Not to say that the other answers here don't have merit, they make some good points. But I'm going to go against the general consensus and agree with you that moving to websockets for more than just realtime features is very appealing.
I am seriously considering moving my app...
What is the difference between association, aggregation and composition?
What is the difference between association, aggregation, and composition?
Please explain in terms of implementation.
19 An...