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PostgreSQL: Difference between text and varchar (character varying)
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There is no difference, under the hood it's all varlena (variable length array).
Check this article from Depesz: http://www.depesz.com/index.php/2010/03/02/charx-vs-varcharx-vs-varchar-vs-text/
A couple of highlights:
To sum it all up:
char(n) – takes t...
Generating an Excel file in ASP.NET [closed]
... am about to add a section to an ASP.NET app (VB.NET codebehind) that will allow a user to get data returned to them as an Excel file, which I will generate based on database data. While there are several ways of doing this, each has its own drawbacks. How would you return the data? I'm looking...
HTML: Include, or exclude, optional closing tags?
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The optional ones are all ones that should be semantically clear where they end, without needing the end tag.
E.G. each <li> implies a </li> if there isn't one right before it.
The forbidden end tags all would be immediately followe...
如何选择机器学习算法 - 大数据 & AI - 清泛网移动版 - 专注IT技能提升
...g algorithm to choose for your classification problem? Of course, if you really care about accuracy, your best bet is to test out a couple different ones (making sure to try different parameters within each algorithm as well), and select the best one by cross-validation. But if you’re simply l...
如何选择机器学习算法 - 大数据 & AI - 清泛网移动版 - 专注IT技能提升
...g algorithm to choose for your classification problem? Of course, if you really care about accuracy, your best bet is to test out a couple different ones (making sure to try different parameters within each algorithm as well), and select the best one by cross-validation. But if you’re simply l...
如何选择机器学习算法 - 大数据 & AI - 清泛网移动版 - 专注IT技能提升
...g algorithm to choose for your classification problem? Of course, if you really care about accuracy, your best bet is to test out a couple different ones (making sure to try different parameters within each algorithm as well), and select the best one by cross-validation. But if you’re simply l...
如何选择机器学习算法 - 大数据 & AI - 清泛网移动版 - 专注IT技能提升
...g algorithm to choose for your classification problem? Of course, if you really care about accuracy, your best bet is to test out a couple different ones (making sure to try different parameters within each algorithm as well), and select the best one by cross-validation. But if you’re simply l...
如何选择机器学习算法 - 大数据 & AI - 清泛网移动版 - 专注IT技能提升
...g algorithm to choose for your classification problem? Of course, if you really care about accuracy, your best bet is to test out a couple different ones (making sure to try different parameters within each algorithm as well), and select the best one by cross-validation. But if you’re simply l...
如何选择机器学习算法 - 大数据 & AI - 清泛网移动版 - 专注IT技能提升
...g algorithm to choose for your classification problem? Of course, if you really care about accuracy, your best bet is to test out a couple different ones (making sure to try different parameters within each algorithm as well), and select the best one by cross-validation. But if you’re simply l...
如何选择机器学习算法 - 大数据 & AI - 清泛网移动版 - 专注IT技能提升
...g algorithm to choose for your classification problem? Of course, if you really care about accuracy, your best bet is to test out a couple different ones (making sure to try different parameters within each algorithm as well), and select the best one by cross-validation. But if you’re simply l...
