大约有 44,000 项符合查询结果（耗时：0.0233秒） [XML]
内存优化总结:ptmalloc、tcmalloc和jemalloc - 操作系统(内核) - 清泛网 - ...
... 总共32个vcpu。 16个table，每个5M row。
OLTP_RO测试包含5个select查询：select_ranges, select_order_ranges, select_distinct_ranges, select_sum_ranges,
可以看到在多核心或者多线程的场景下， jemalloc和tcmalloc带来的tps增加非常明显。
参考资料
glibc...
How to find the mysql data directory from command line in windows
... the following command line:
mysql -s -N -uUSER -p information_schema -e 'SELECT Variable_Value FROM GLOBAL_VARIABLES WHERE Variable_Name = "datadir"'
The command will select the value only from mysql's internal information_schema database and disables the tabular output and column headers.
Outp...
How to remove a key from Hash and get the remaining hash in Ruby/Rails?
...m a hash and get the remaining hash in Ruby.
.slice => It will return selected keys and not delete them from the original hash. Use slice! if you want to remove the keys permanently else use simple slice.
2.2.2 :074 > hash = {"one"=>1, "two"=>2, "three"=>3}
=> {"one"=>1, "tw...
Rails filtering array of objects by attribute value
...
Try :
This is fine :
@logos = @attachments.select { |attachment| attachment.file_type == 'logo' }
@images = @attachments.select { |attachment| attachment.file_type == 'image' }
but for performance wise you don't need to iterate @attachments twice :
@logos , @images...
How to change default text file encoding in Eclipse?
...needed to do is:
Window > Preferences > General > Content Types
Select Text > HTML in the tree
Select all file associations, particularly .html
Input "UTF-8" in the text-field "default encoding"
share
...
LINQ order by null column where order is ascending and nulls should be last
... descending
orderby p.LowestPrice descending
select p;
will be translated by the compiler to
var products = _context.Products
.Where(p => p.ProductTypeId == 1)
.OrderByDescending(p => p.LowestPrice.HasValue)
...
How to delete a workspace in Perforce (using p4v)?
...
From the "View" menu, select "Workspaces". You'll see all of the workspaces you've created. Select the workspaces you want to delete and click "Edit" -> "Delete Workspace", or right-click and select "Delete Workspace". If the workspace is "lock...
@Override is not allowed when implementing interface method
...In JIdea 2020.1.2 and above,
Go to Project Structure [ Ctrl+Alt+Shift+S
]
Select Modules sub section
Select each module
Under sources-section, check Language Level
Change the Language Level as required
NOTE:
If you get below error after this change,
Error:java: Compilation failed: internal java c...
Any good, visual HTML5 Editor or IDE? [closed]
...E Developers" Latest Stable Version Download Google Plugin for Eclipse.zip Select your download according to your Eclipse Version After Downloading (don't Unzip) Open Eclipse Help > Install New Software > Add > Archive > Select the Downloaded Plug-in.zip
in the field "Name" enter "Google...
How do I convert an enum to a list in C#? [duplicate]
...er way:
Enum.GetValues(typeof(SomeEnum))
.Cast<SomeEnum>()
.Select(v => v.ToString())
.ToList();
share
|
improve this answer
|
follow
|
...