Apache Cassandra static column 介绍与实战 Spark大数据博客 - https://www.iteblog.com Apache Cassandra static column 介绍与实战 假设我们有这样的场景：我们想在 Cassandra 中使用一张表记录用户基本信息（比如 email、密 码等）以及用户状态更新。我们知道，用户的基本信息一般很少会变动，但是状态会经常变化， 间。为了解决这种问题 ，Cassandra 引入了 static column。同一个 partition key 中被声明为 static 的列只有一个值的，也就是只存储一份。 如果想及时了 解Spark、Hadoop或者Hbase相关的文章，欢迎关注微信公共帐号：iteblog_hadoop 定义 static column 在表中将某个列定义为 STATIC 很简单，只需要在列的最后面加上 PRIMARY KEY ("username") 1 / 5 Apache Cassandra static column 介绍与实战 Spark大数据博客 - https://www.iteblog.com ... ); InvalidRequest: Error from

Software 1 Start the Cassandra Server 1 Login to Cassandra 1 Create a Keyspace (database) 1 Create a Column Family 2 Insert, Update, Delete, Read Data 2 Getting Started with Cassandra and DataStax Community Cassandra Data Model to a Relational Database 45 About Keyspaces 47 Defining Keyspaces 47 About Column Families 48 About Columns 49 About Special Columns (Counter, Expiring, Super) 49 About Expiring 50 About Validators 51 About Comparators 51 About Column Family Compression 52 When to Use Compression 52 Configuring Compression on a Column Family 52 About Indexes in Cassandra 52 About Primary

Trailing spaces are not stored in the database but are restored to match the defined length when the column is displayed on the client side. Network traffic is reduced by not sending spaces over the LAN after the point. If the number 3.1415 is written to a column with this data type definition, the value of 3.14 will be saved in the NUMERIC(4, 2) column. The form of declaration for fixed-point data, for precision. For instance, you define the column type as NUMERIC(2,2) presuming that its range of values will be -0.99…0.99. However, the actual range of values for the column will be -327.68..327.67, which is

. . . . . . . . . . . . . . . . . . . . 61 Logic Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Cipher Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Query Assistant Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Plain Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 Identifier Rewrite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 Column Derivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 Pagination Revision

. . . . . . . . . . . . . . . . . . . . 59 Logic Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Cipher Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Query Assistant Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Plain Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 Identifier Rewrite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 Column Derivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 Pagination Revision

type REAL is a synonym for FLOAT, and is provided for syntax compatibility. When used to define a column or parameter, it’s indistinguishable from using FLOAT or FLOAT(1) - FLOAT(24).  Compatibility after the point. If the number 3.1415 is written to a column with this data type definition, the value of 3.14 will be saved in the NUMERIC(4, 2) column. The form of declaration for fixed-point data, for precision. For instance, you define the column type as NUMERIC(2,2) presuming that its range of values will be -0.99…0.99. However, the actual range of values for the column will be -327.68…327.67, which is

............................................................................. 38 Setting output column width: .................................................................... 39 Schema Information: The CREATE INDEX Command: ........................................................... 101 Single-Column Indexes: ......................................................................... 101 Unique Indexes: is implemented. ALTER TABLE The RENAME TABLE and ADD COLUMN variants of the ALTER TABLE command are supported. The DROP COLUMN, ALTER COLUMN, ADD CONSTRAINT not supported. Trigger support FOR EACH

. . . . . . . . . . . . . . . . . . . . 62 Logic Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Cipher Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Query Assistant Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Plain Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Shadow algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Column shadow algorithm DML statement support list . . . . . . . . . . . . . . 65 5 User Manual 67 5.1

. . . . . . . . . . . . . . . . . . . . 46 Logic column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Cipher column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Query assistant column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Plain column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Hint based shadow algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Column based shadow algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . 49 3.10 Observability

Definition Basics 323 Default Column Values 324 Generated Columns 325 Creating and Managing Tables 326 Creating a Table 326 Choosing Column Data Types 326 Setting Table and Column Constraints 327 Check 333 Append-Optimized Storage 334 To create a heap table 334 Choosing Row or Column-Oriented Storage 334 To create a column-oriented table 335 Using Compression (Append-Optimized Tables Only) 336 To for Run-length Encoding 338 Adding Column-level Compression 338 Default Compression Values 340 Precedence of Compression Settings 340 Optimal Location for Column Compression Settings 341 Storage Parameters