Slide 1
... • Creating a new copy each time is essential – If it were to be created once and then stored on the user’s computer, then there would be two copies of the information • The other advantage of creating specialized versions of the database for each user is that different users want to see different in ...
... • Creating a new copy each time is essential – If it were to be created once and then stored on the user’s computer, then there would be two copies of the information • The other advantage of creating specialized versions of the database for each user is that different users want to see different in ...
A SQL:1999 Code Generator for the Pathfinder XQuery
... of intermediate language has its particular strengths. On the one hand, the semantics of relational algebra are well-defined and independent of any particular database back-end. A Pathfinder back-end for the MonetDB column store is described in [2]. On the other hand, the algebraic primitives model ...
... of intermediate language has its particular strengths. On the one hand, the semantics of relational algebra are well-defined and independent of any particular database back-end. A Pathfinder back-end for the MonetDB column store is described in [2]. On the other hand, the algebraic primitives model ...
An Introduction to SQL
... Data Types For each column in a table, the type of data that the column will store must be specified The exact list of data types available in different implementations of SQL varies ...
... Data Types For each column in a table, the type of data that the column will store must be specified The exact list of data types available in different implementations of SQL varies ...
Chapter 5 Integrity Constraints
... ⅰThe problem of ensuring that the database does not include any invalid foreign key values is therefore known as the referential integrity problem. ⅱ The constraint that values of a given foreign key must match values of the corresponding candidate key is known as the a referential constraint. ⅲ We ...
... ⅰThe problem of ensuring that the database does not include any invalid foreign key values is therefore known as the referential integrity problem. ⅱ The constraint that values of a given foreign key must match values of the corresponding candidate key is known as the a referential constraint. ⅲ We ...
What`s Wrong with ER Modeling
... • No multi-valued, non-key attributes (1NF) • No partial dependencies on non-key attributes (2NF) • No transitive dependencies in non-key attributes (3NF) • No partial or transitive dependencies within any key (EKNF, BCNF), i.e., consider all candidate keys. • No multiple, independent multi-valued a ...
... • No multi-valued, non-key attributes (1NF) • No partial dependencies on non-key attributes (2NF) • No transitive dependencies in non-key attributes (3NF) • No partial or transitive dependencies within any key (EKNF, BCNF), i.e., consider all candidate keys. • No multiple, independent multi-valued a ...
ID110_Chapter 21
... containment mapping from one conjunctive query to another. Importance of containment mappings is expressed by the theorem: If Q1 and A2 are conjunctive queries, then Q2 is subset or equal to Q1, if and only if there is a containment mapping from Q1 and Q2. ...
... containment mapping from one conjunctive query to another. Importance of containment mappings is expressed by the theorem: If Q1 and A2 are conjunctive queries, then Q2 is subset or equal to Q1, if and only if there is a containment mapping from Q1 and Q2. ...
Elmasri/Navathe, Fundamentals of Database Systems, Fourth Edition
... Ordering of tuples in a relation r(R): The tuples are not considered to be ordered, even though they appear to be in the tabular form. Ordering of attributes in a relation schema R (and of values within each tuple): We will consider the attributes in R(A1, A2, ..., An) and the values in t=
... Ordering of tuples in a relation r(R): The tuples are not considered to be ordered, even though they appear to be in the tabular form. Ordering of attributes in a relation schema R (and of values within each tuple): We will consider the attributes in R(A1, A2, ..., An) and the values in t=
Basic SQL statements: DDL and DML
... Constraints, as well as to make other modifications to the table structure. Key constraints may also be specified in the CREATE TABLE statement. Alter table
Add constraint
... Constraints, as well as to make other modifications to the table structure. Key constraints may also be specified in the CREATE TABLE statement. Alter table
