Search results
Results from the WOW.Com Content Network
Shorthand may also be used, taking advantage of the order of the columns when the table was created. It is not required to specify all columns in the table since any other columns will take their default value or remain null: INSERT INTO table VALUES (value1, [value2, ...
Type 2 (Add new row): A new row is created with either a start date / end date or a version for a new value. This creates history. Type 3 (Add new attribute): A new column is created for a new value. History is limited to the number of columns designated for storing historical data. Type 4 (Add history table): One table keeps the current value ...
A wide-column store (or extensible record store) is a 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–value store. [1]
A new dimension row is added with the new state of the source system; a new surrogate key is assigned; source key is no longer unique in the lookup table Fully logged A new dimension row is added with the new state of the source system, while the previous dimension row is updated to reflect it is no longer active and time of deactivation.
An inner join (or join) requires each row in the two joined tables to have matching column values, and is a commonly used join operation in applications but should not be assumed to be the best choice in all situations. Inner join creates a new result table by combining column values of two tables (A and B) based upon the join-predicate.
Title Authors ----- ----- SQL Examples and Guide 4 The Joy of SQL 1 An Introduction to SQL 2 Pitfalls of SQL 1 Under the precondition that isbn is the only common column name of the two tables and that a column named title only exists in the Book table, one could re-write the query above in the following form:
A super column family is a NoSQL object that contains column families. It is a tuple (pair) that consists of a key–value pair, where the key is mapped to a value that are column families. [1] In analogy with relational databases, a super column family is something like a "view" on a number of tables. It can also be seen as a map of tables. [2]
Title Authors ----- ----- SQL Examples and Guide 4 The Joy of SQL 1 An Introduction to SQL 2 Pitfalls of SQL 1 Under the precondition that isbn is the only common column name of the two tables and that a column named title only exists in the Book table, one could re-write the query above in the following form: