Search results
Results from the WOW.Com Content Network
Database designers that use a surrogate key as the primary key for every table will run into the occasional scenario where they need to automatically retrieve the database-generated primary key from an SQL INSERT statement for use in other SQL statements. Most systems do not allow SQL INSERT statements to return row data. Therefore, it becomes ...
SQL term Relational database term Description Row: Tuple or record: A data set representing a single item Column: Attribute or field: A labeled element of a tuple, e.g. "Address" or "Date of birth" Table: Relation or Base relvar: A set of tuples sharing the same attributes; a set of columns and rows View or result set: Derived relvar
Oracle Database provides information about all of the tables, views, columns, and procedures in a database. This information about information is known as metadata. [1] It is stored in two locations: data dictionary tables (accessed via built-in views) and a metadata registry.
Indexes can be created using one or more columns of a database table, providing the basis for both rapid random lookups and efficient access of ordered records. An index is a copy of selected columns of data, from a table, that is designed to enable very efficient search.
For example, a table of 128 rows with a Boolean column requires 128 bytes a row-oriented format (one byte per Boolean) but 128 bits (16 bytes) in a column-oriented format (via a bitmap). Another example is the use of run-length encoding to encode a column.
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]
The OFFSET clause specifies the number of rows to skip before starting to return data. The FETCH FIRST clause specifies the number of rows to return. Some SQL databases instead have non-standard alternatives, e.g. LIMIT, TOP or ROWNUM. The clauses of a query have a particular order of execution, [5] which is denoted by the number on the right ...
The database schema is the structure of a database described in a formal language supported typically by a relational database management system (RDBMS). The term " schema " refers to the organization of data as a blueprint of how the database is constructed (divided into database tables in the case of relational databases ).