大约有 40,000 项符合查询结果（耗时：0.0351秒） [XML]
Python: List vs Dict for look up table
...the hash table, only pointers, i.e. hou have 40M for the ints (well, not really when a lot of them are small) and 60M for the hash table. I agree that it's not that much of a problem nowadays, still it's worthwhile to keep in mind.
– Torsten Marek
Feb 5 '09 at ...
How is Python's List Implemented?
...dynamic array. Practical proof: Indexing takes (of course with extremely small differences (0.0013 µsecs!)) the same time regardless of index:
...>python -m timeit --setup="x = [None]*1000" "x[500]"
10000000 loops, best of 3: 0.0579 usec per loop
...>python -m timeit --setup="x = [None]*100...
Utilizing multi core for tar+gzip/bzip compression/decompression
I normally compress using tar zcvf and decompress using tar zxvf (using gzip due to habit).
6 Answers
...
When to prefer JSON over XML?
...erate with environments that don't support JSON
Favor JSON over XML when all of these are true:
Messages don't need to be validated, or validating their deserialization is simple
You're not transforming messages, or transforming their deserialization is simple
Your messages are mostly data, not ...
Is there a way to access an iteration-counter in Java's for-each loop?
...ide your own counter.
The reason for this is that the for-each loop internally does not have a counter; it is based on the Iterable interface, i.e. it uses an Iterator to loop through the "collection" - which may not be a collection at all, and may in fact be something not at all based on indexes (...
Quickly create large file on a Windows system
... Just want to check if this is a sparse file or does the file actually have data in it?
– slolife
Jun 2 '11 at 17:35
2
...
C#: List All Classes in Assembly
I'd like to output (programmatically - C#) a list of all classes in my assembly.
2 Answers
...
SQL Server IN vs. EXISTS Performance
...l quit looking as the condition has proved true.
With IN, it will collect all the results from the sub-query before further processing.
share
|
improve this answer
|
follow
...
Quickly create a large file on a Linux system
... it is slow for this purpose. In Linux (and other POSIX systems), we have fallocate, which uses the desired space without having to actually writing to it, works with most modern disk based file systems, very fast:
For example:
fallocate -l 10G gentoo_root.img
...
How to get cumulative sum
...
@Franklin Only cost efficient for small tables. Cost grows proportional to the square of the number of rows. SQL Server 2012 allows this to be done much more efficiently.
– Martin Smith
May 18 '13 at 19:57
...