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When to use Hadoop, HBase, Hive and Pig?
...ru some SQL like language
To replace daily aggregation data generated thru MySQL with Hive
Build Custom reports thru queries in Hive
Architecture Options
I benchmarked the following options:
Hive+HDFS
Hive+HBase - queries were too slow so I dumped this option
Design
Daily log Files were tr...
How to remove all namespaces from XML with C#?
...
the obligatory answer using LINQ:
static XElement stripNS(XElement root) {
return new XElement(
root.Name.LocalName,
root.HasElements ?
root.Elements().Select(el => stripNS(el)) :
(object)root.Value
);
}
static void Main() {
var xml = X...
MySql: Tinyint (2) vs tinyint(1) - what is the difference?
I knew boolean in mysql as tinyint (1) .
4 Answers
4
...
“INSERT IGNORE” vs “INSERT … ON DUPLICATE KEY UPDATE”
... but the values you insert don't map to a partition.
If you use REPLACE, MySQL actually does a DELETE followed by an INSERT internally, which has some unexpected side effects:
A new auto-increment ID is allocated.
Dependent rows with foreign keys may be deleted (if you use cascading foreign ke...
Cast int to varchar
... @JonathanSayce I'm not overly familiar with the ins & outs of MySQL and it might not use something arbitrary, but I wouldn't rely on the MySQL engine to be that smart (no offense to MySQL). In order to be sure you get the proper length, I would always explicitly provide one.
...
os.walk without digging into directories below
... os.path.isdir(some_dir)
num_sep = some_dir.count(os.path.sep)
for root, dirs, files in os.walk(some_dir):
yield root, dirs, files
num_sep_this = root.count(os.path.sep)
if num_sep + level <= num_sep_this:
del dirs[:]
It works just like os.walk, but y...
Is the primary key automatically indexed in MySQL?
...
According to http://dev.mysql.com/doc/refman/5.0/en/constraint-primary-key.html it would appear that this is would be implicit
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Deep Learning（深度学习）学习笔记整理系列之（二） - 大数据 & AI - 清泛...
...，不妨把这个碎片标记为 T。
他们提出的问题是，如何从这400个碎片中，选取一组碎片，S[k], 通过叠加的办法，合成出一个新的碎片，而这个新的碎片，应当与随机选择的目标碎片 T，尽可能相似，同时，S[k] 的数量尽可...
Deep Learning（深度学习）学习笔记整理系列之（二） - 大数据 & AI - 清泛...
...，不妨把这个碎片标记为 T。
他们提出的问题是，如何从这400个碎片中，选取一组碎片，S[k], 通过叠加的办法，合成出一个新的碎片，而这个新的碎片，应当与随机选择的目标碎片 T，尽可能相似，同时，S[k] 的数量尽可...
Deep Learning（深度学习）学习笔记整理系列之（二） - 大数据 & AI - 清泛...
...，不妨把这个碎片标记为 T。
他们提出的问题是，如何从这400个碎片中，选取一组碎片，S[k], 通过叠加的办法，合成出一个新的碎片，而这个新的碎片，应当与随机选择的目标碎片 T，尽可能相似，同时，S[k] 的数量尽可...