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实战低成本服务器搭建千万级数据采集系统 - 更多技术 - 清泛网 - 专注C/C++...
...器。到了机器后再按照天或者半天分表，比如表名为 weibo_2013020101 、weibo_2013020112。weibo_2013020101表示2月1日上午一个表，weibo_2013020112表示2月1日下午一个表。光这样分了还是不够，1000w/2=500w，经不起压力扩展。我们还需要把表再...
How do I reset a sequence in Oracle?
...
alter sequence serial restart start with 1;
This feature was officially added in 18c but is unofficially available since 12.1.
It is arguably safe to use this undocumented feature in 12.1. Even though the syntax is not included in the official documentation, it is generated by the Oracle pa...
How to send data to local clipboard from a remote SSH session
... to a linux server via SSH. Like the OP, I wanted to be able to transfer small bits of text from terminal to my local clipboard, using only the keyboard.
The essence of the solution:
commandThatMakesOutput | ssh desktop pbcopy
When run in an ssh session to a remote computer, this command takes...
Optimize Font Awesome for only used classes
...
Sass has no idea what classes you are actually using. This is something you will have to manually trim down yourself. Open up the provided .scss file and hack out anything you don't need.
Editing the font file itself to eliminate unneeded glyphs requires a 3rd pa...
Why would one omit the close tag?
...e file (and possibly some other factors I don't want to bore you with).
Finally, many PHP frameworks including Symfony, Zend and Laravel (there is no mention of this in the coding guidelines but it follows the suit) and the PSR-2 standard (item 2.2) require omission of the closing tag. PHP manual it...
How to create CSV Excel file C#? [closed]
... public void ExportToFile(string path)
{
File.WriteAllText(path, Export());
}
//export as binary data.
public byte[] ExportToBytes()
{
return Encoding.UTF8.GetBytes(Export());
}
//get the csv value for field.
...
How to fix the flickering in User controls
...f controls, those holes are visible to the user for a while. They are normally white, contrasting badly with the BackgroundImage when it is dark. Or they can be black if the form has its Opacity or TransparencyKey property set, contrasting badly with just about anything.
This is a pretty fundamen...
Saving image from PHP URL
...
If you have allow_url_fopen set to true:
$url = 'http://example.com/image.php';
$img = '/my/folder/flower.gif';
file_put_contents($img, file_get_contents($url));
Else use cURL:
$ch = curl_init('http://example.com/image.php');
$fp = f...
Oracle SQL: Update a table with data from another table
...
This is called a correlated update
UPDATE table1 t1
SET (name, desc) = (SELECT t2.name, t2.desc
FROM table2 t2
WHERE t1.id = t2.id)
WHERE EXISTS (
SELECT 1
FROM table2 t2...
How to replace NaN values by Zeroes in a column of a Pandas Dataframe?
...olumn, select just that column. in this case I'm using inplace=True to actually change the contents of df.
In [12]: df[1].fillna(0, inplace=True)
Out[12]:
0 0.000000
1 0.570994
2 0.000000
3 -0.229738
4 0.000000
Name: 1
In [13]: df
Out[13]:
0 1
0 NaN 0.0000...