如何筛选Cassandra中的数据？ [英] How do I filter through data in Cassandra?
问题描述
我一直在使用mySQL的应用程序一段时间，我收集的数据越多，它得到的速度越慢。所以我一直在研究NOSQL选项。我在我的SQL中的一个东西是一个视图从一堆连接创建。该应用程序显示网格中的所有重要信息，用户可以选择范围，搜索等。在此数据集。标准查询内容。
I've been using mySQL for an app for some time, and the more data I collect, the slower it gets. So I have been looking into NOSQL options. One of the things I have in mySQL is a View created from a bunch of joins. The app shows all the important info in a grid, and the user can select ranges, do searches, etc. On this data set. Standard Query stuff.
查看Cassandra一切都已经根据我在storage-conf.xml中提供的参数排序。所以我会有一个特定的字符串作为我的关键在SuperColumn，并保留在列下面的一堆数据。但我只能排序一个列，我不能做任何真正的搜索，而不拉所有的SuperColumns，循环的数据，对吗？
Looking at Cassandra everything is already sorted based on the parameters I provide in my storage-conf.xml. So I would have a certain string as my key in the SuperColumn, and keep a bunch of the data in Columns below that. But I can only sort by one Column, and I can't do any real searching within the columns without pulling all the SuperColumns, and looping through the data, right?
我不想跨不同的ColumnFamilies重复数据，所以我想确保Cassandra适合我。在Facebook，Digg，Twitter，他们有很多搜索功能，所以也许我只是看不到解决方案。
I don't want to duplicate data across different ColumnFamilies, so I want to make sure Cassandra is appropriate for me. In Facebook, Digg, Twitter, they have plenty of searching functions, so maybe I am just not seeing the solution.
Cassandra是否有办法在SuperColumn或其相关列中搜索或过滤特定数据值？如果没有，是否有另一个NOSQL选项？
Is there a way with Cassandra for me to search for or filter specific data values in a SuperColumn, or its associated Column(s)? If not, is there another NOSQL option?
在下面的例子中，似乎我只能查询phatduckk，friend1，John等等。但是如果我想找到居住在城市的ColumnFamily中的任何人==Beverley Hills？是否可以在不返回所有记录的情况下完成？如果是这样，我可以搜索city ==Beverley HillsAND state ==CA？它似乎不是我能做的，但我想确保看看我的选择是什么。
In the example below, it seems I can only query for phatduckk, friend1,John, etc. But what if I wanted to find anyone in the ColumnFamily that lived in city == "Beverley Hills"? Can it be done without returning all records? If so, could I do a search for city == "Beverley Hills" AND state == "CA"? It doesn't seem like I can do either, but I want to make sure and see what my options are.
AddressBook = { // this is a ColumnFamily of type Super
phatduckk: { // this is the key to this row inside the Super CF
friend1: {street: "8th street", zip: "90210", city: "Beverley Hills", state: "CA"},
John: {street: "Howard street", zip: "94404", city: "FC", state: "CA"},
Kim: {street: "X street", zip: "87876", city: "Balls", state: "VA"},
Tod: {street: "Jerry street", zip: "54556", city: "Cartoon", state: "CO"},
Bob: {street: "Q Blvd", zip: "24252", city: "Nowhere", state: "MN"},
}, // end row
ieure: {
joey: {street: "A ave", zip: "55485", city: "Hell", state: "NV"},
William: {street: "Armpit Dr", zip: "93301", city: "Bakersfield", state: "CA"},
},
}
推荐答案
您不能在Cassandra中执行这些操作。有一些种类的选择谓词可以在列键上设置，但是它们所保存的值没有任何值。查看 API 并检查get_slice / get_superslice和get_range查询类型。同样，所有这一切都涉及ColumnFamily或SuperColumnFamily中的键不是值。
You cannot perform those kind of operations in Cassandra. There is a certain kinds of selection predicates that can be set on column-keys but nothing on the value that they hold. Look at the API and check get_slice/get_superslice and get_range query types. Again, all of this is concerning the keys in the ColumnFamily or SuperColumnFamily not the values.
如果你想要你所描述的那种功能，那么最好的办法是使用SQL数据库。在表上构建正确的索引，特别是在最被查询的列上，您会发现查询性能有很大的不同。希望这有助于。
If you want the kind of functionality that you have described then your best bet is a SQL database. Build proper indexes on your tables, especially on the columns that are most queried and you will see a big difference in the query performance. Hope this helps.
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