SQL-on-Hadoop, NewSQL and NoSQL databases provide semi-structured data models (typically JSON based) and respective query languages. Lack of formal syntax and semantics, idiomatic (nonSQL) language constructs and large variations in syntax, semantics and actual capabilities pose problems even to database experts: It is hard to understand, compare and use these languages. It is especially tediou...

We consider IES(SQL), the incremental evaluation system over an SQL-like language with grouping, arithmetics, and aggregation. We show that every second order query is in IES(SQL) and that there are PSPACE-complete queries in IES(SQL). We further show that every PSPACE query is in IES(SQL) augmented with a deterministic transitive closure operator. Lastly, we consider ordered databases and prov...

If you want to get SQL, Second Edition pdf eBook copy write by good author Fehily, Chris, SQL Injection Attacks and Defense, Second Edition / BackTrack. Confirming and Recovering from SQL Injection Attacks Introduction an SQL injection flaw (ftc.gov/os/caselist/0523148/0523148complaint.pdf), a hacker. One of the most easiest and hazardous security attacks confronted by these systems is SQL inje...

The SkyServer is an Internet portal to the Sloan Digital Sky Survey Catalog Archive Server. From 2001 to 2006, there were a million visitors in 3 million sessions generating 170 million Web hits, 16 million ad-hoc SQL queries, and 65 million page views. The site currently averages 35 thousand visitors and 400 thousand sessions per month. The Web and SQL logs are public. We analyzed traffic and ...

We consider the efficiency of queries generated by XML to SQL translation. We first show that published XML-to-SQL query translation algorithms are suboptimal in that they often translate simple path expressions into complex SQL queries even when much simpler equivalent SQL queries exist. There are two logical ways to deal with this problem. One could generate suboptimal SQL queries using a fai...

Formal specification and verification is required for high security level DBMS in the top level specification design. The specification and verification towards SQL operations is important especially. In this paper, we propose a novel approach to solve the specification and verification issues towards SQL operations. Firstly, we formally define the SQL operations in FTLS; then, we give the defi...

Current search engines can hardly cope adequately with complex preferences. The biggest problem of search engines directly implemented with standard SQL is that SQL does not directly understand the notion of preferences. Preference SQL extends standard SQL by a preference model based on strict partial orders, where preference queries behave like soft selection constraints. A variety of built-in...

Structured Query Language (SQL) is an ANSI and ISO standard declarative query language for querying and manipulating relational databases. It is easy to write SQL queries but very difficult to validate them. Often students conclude that a SQL query is correct simply because the query compiles, executes, and fetches data. Therefore, it is crucial that SQL assessment tasks are carefully designed ...

Among the various types of software vulnerabilities, command injection is the most common type of threat in web applications. In command injection, SQL injection type of attacks are extremely prevalent, and ranked as the second most common form of attack on web. SQL injection attacks involve the construction of application’s input data that will result in the execution of malicious SQL statemen...