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Data orientation. Data orientation refers to how tabular data is represented in a linear memory model such as in-disk or in-memory .The two most common representations are column-oriented (columnar format) and row-oriented (row format). [1] [2]
The SQL SELECT statement returns a result set of rows, from one or more tables. [1] [2] A SELECT statement retrieves zero or more rows from one or more database tables or database views. In most applications, SELECT is the most commonly used data manipulation language (DML) command. As SQL is a declarative programming language, SELECT queries ...
SQL includes operators and functions for calculating values on stored values. SQL allows the use of expressions in the select list to project data, as in the following example, which returns a list of books that cost more than 100.00 with an additional sales_tax column containing a sales tax figure calculated at 6% of the price.
In a database, a table is a collection of related data organized in table format; consisting of columns and rows . In relational databases, and flat file databases, a table is a set of data elements (values) using a model of vertical columns (identifiable by name) and horizontal rows, the cell being the unit where a row and column intersect. [ 1]
SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Edgar F. Codd [12] in the early 1970s. [13] This version, initially called SEQUEL (Structured English Query Language), was designed to manipulate and retrieve data stored in IBM's original quasirelational database management system, System R, which a group at IBM San ...
A wide-column store (or extensible record store) is a column-oriented DBMS and therefore a special type of NoSQL database. [ 1] It uses tables, rows, and columns, but unlike a relational database, the names and format of the columns can vary from row to row in the same table. A wide-column store can be interpreted as a two-dimensional key ...
Column (database) In a relational database, a column is a set of data values of a particular type, one value for each row of a table. [ 1] A column may contain text values, numbers, or even pointers to files in the operating system. [ 2] Columns typically contain simple types, though some relational database systems allow columns to contain ...
Flat-file database. A flat-file database is a database stored in a file called a flat file. Records follow a uniform format, and there are no structures for indexing or recognizing relationships between records. The file is simple. A flat file can be a plain text file (e.g. csv, txt or tsv ), or a binary file. Relationships can be inferred from ...