java - How do you use "Range" to Scan an entire table in accumulo

Question

How do you use "Range" to Scan an entire table in accumulo without apriori knowledge?

How do folks currently do that. I want to take the random search from:I am looking at writing an Accumulo iterator to return a random sample of a percentile of a table

and scan over (then write to hdfs) a sample.

This requires me to scan the entire table I believe.

thanks!

Chris

Answer 1

这与上一个答案所说的相同，但我认为显示一行代码可能会有所帮助。

如果你有一个扫描仪，巧妙地命名为“扫描仪”，你可以使用 setRange() 方法来设置扫描仪的范围。因为默认范围是 (-inf, +inf)，所以传递 setRange 一个新创建的范围对象将使您的扫描仪能够扫描整个表，范围为 (-inf, +inf)。

示例代码如下所示：

scanner.setRange(new Range());

Answer 2

您可以使用无参数构造函数扫描整个表。根据以下文档Range()：

Creates a range that goes from negative to positive infinity.