Sql Single Quotes

Different databases are designed to solve different problems. Using a single database engine for all of the requirements usually leads to non- performant solutions; storing transactional data, caching session information, traversing graph of customers and the products their friends bought are essentially different problems.

Complex applications combine different types of problems, so picking the right language for each job may be more productive than trying to fit all aspects into a single language.

When expressing a regular character literal, you simply use single quotes: ‘This is a regular character string literal’. When expressing a Unicode character literal, you need to specify the character N (for National) as a prefix: N’This is a Unicode character string literal’.

The way xp_ cmdshell works is very simple: It takes a single string argument and then executes that as a command-line call. For example, the call would perform a directory listing of the server’s C drive. Again, at this point the damage is limited only by the attacker’s imagination, and exploiting this through SQL injection is absolutely trivial: If you’re running SQL Server, we strongly recommend disabling or removing the xp_cmdshell stored procedure. You can disable it through use of the sp_configure stored procedure, like so:

Martin Fowler NoSQL Distilled: "In general, with remote communication you want to reduce the number of round trips involved in the interaction, so it’s useful to be able to put a rich structure of information into a single request or response." Patterns of Enterprise Application Architecture" "Due to the latency costs of remote calls, it's better to err on the side of sending too much data than have to make multiple calls.

or custom

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

You can scale without increasing availability or uptime. 

In many cases it makes sense to scale your web servers horizontally while you scale your database servers vertically. 

Running multiple services on a single node is sometimes referred to as pancaking. 

Also, _netdev signals that networking needs to be started before the file system mount is even attempted.