Sql Columns Quotes

The presence of a column named id in every table is so common that this has become synonymous with a primary key. Programmers learning SQL get the false idea that a primary key always means a column defined in this manner.

Features of Cassandra In order to keep this chapter short, the following bullet list covers the great features provided by Cassandra: Written in Java and hence providing native Java support Blend of Google BigTable and Amazon Dynamo Flexible schemaless column-family data model Support for structured and unstructured data Decentralized, distributed peer-to-peer architecture Multi-data center and rack-aware data replication Location transparent Cloud enabled Fault-tolerant with no single point of failure An automatic and transparent failover Elastic, massively, and linearly scalable Online node addition or removal High Performance Built-in data compression Built-in caching layer Write-optimized Tunable consistency providing choices from very strong consistency to different levels of eventual consistency Provision of Cassandra Query Language (CQL), a SQL-like language imitating INSERT, UPDATE, DELETE, SELECT syntax of SQL Open source and community-driven

When you execute a program that retrieves a small subset of rows from a large table, it can be time-consuming for PROC SQL to read the rows sequentially. In some situations, using an index on a table allows PROC SQL to access a subset of rows more efficiently. An index stores unique values for a specified column or columns in ascending value order, and includes information about the location of those values in the table. That is, an index is composed of value/identifier pairs that enable you to access a row directly, by value. For example, suppose you have created an index on your table that is based