Physical Database Design(1)
... After logical design, we have a “good” logical schema that describes the data to be stored and related constraints; The next step is physical database design, a process of producing a physical schema, i.e., a description of the implementation of the database on secondary storage using the target DBM ...
... After logical design, we have a “good” logical schema that describes the data to be stored and related constraints; The next step is physical database design, a process of producing a physical schema, i.e., a description of the implementation of the database on secondary storage using the target DBM ...
Chapter 4 Implementation of Relational Operators
... The optimizer then considers combining each pair of relations for which a join condition exists. For each pair, the optimizer will consider the available join algorithms implemented by the DBMS. It will preserve the cheapest way to join each pair of relations, in addition to the cheapest way to join ...
... The optimizer then considers combining each pair of relations for which a join condition exists. For each pair, the optimizer will consider the available join algorithms implemented by the DBMS. It will preserve the cheapest way to join each pair of relations, in addition to the cheapest way to join ...
Chapter 7: Relational Database Design
... Note the use of the dot notation to access fields of the composite attribute (structured type) publisher ...
... Note the use of the dot notation to access fields of the composite attribute (structured type) publisher ...
Chapter 7: Relational Database Design
... Note the use of the dot notation to access fields of the composite attribute (structured type) publisher ...
... Note the use of the dot notation to access fields of the composite attribute (structured type) publisher ...
Publisher
... Note the use of the dot notation to access fields of the composite attribute (structured type) publisher ...
... Note the use of the dot notation to access fields of the composite attribute (structured type) publisher ...
Query Optimization
... The rest of the chapter is organized as follows. Section 2 presents a modular architecture for a query optimizer and describes the role of each module in it. Section 3 analyzes the choices that exist in the shapes of relational query access plans, and the restrictions usually imposed by current opti ...
... The rest of the chapter is organized as follows. Section 2 presents a modular architecture for a query optimizer and describes the role of each module in it. Section 3 analyzes the choices that exist in the shapes of relational query access plans, and the restrictions usually imposed by current opti ...
Consistent Query Answering: Five Easy Pieces
... Sources of inconsistency: ∙ integration of independent data sources with overlapping data ∙ time lag of updates (eventual consistency) ∙ unenforced integrity constraints ...
... Sources of inconsistency: ∙ integration of independent data sources with overlapping data ∙ time lag of updates (eventual consistency) ∙ unenforced integrity constraints ...
MYCH3
... IC: condition that must be true for any instance of the database; e.g., domain constraints. ...
... IC: condition that must be true for any instance of the database; e.g., domain constraints. ...
Extracting UML/OCL Integrity Constraints and Derived Types from Relational Databases
... clause. The mapping is basically a direct mapping since the references to the column names in the WHERE are replaced by the corresponding attribute and association names. SQL functions are translated into their OCL counterparts (if existing, otherwise new OCL operations must be previously defined, ...
... clause. The mapping is basically a direct mapping since the references to the column names in the WHERE are replaced by the corresponding attribute and association names. SQL functions are translated into their OCL counterparts (if existing, otherwise new OCL operations must be previously defined, ...
Methodology – Physical Database Design
... quickly and thereby speed response to user queries. Types of Indexes: • Primary Index: the data file is sequentially ordered by an ordering key field, and the indexing field is built on the ordering key field (unique). • Clustering Index: the data file is sequentially ordered on a non-key field (not ...
... quickly and thereby speed response to user queries. Types of Indexes: • Primary Index: the data file is sequentially ordered by an ordering key field, and the indexing field is built on the ordering key field (unique). • Clustering Index: the data file is sequentially ordered on a non-key field (not ...
SQL
... • LEFT JOIN: Return all rows from the left table, even if there are no matches in the right table • RIGHT JOIN: Return all rows from the right table, even if there are no matches in the left table • FULL JOIN: Return rows when there is a match in one of the tables ...
... • LEFT JOIN: Return all rows from the left table, even if there are no matches in the right table • RIGHT JOIN: Return all rows from the right table, even if there are no matches in the left table • FULL JOIN: Return rows when there is a match in one of the tables ...
Document
... dependencies and multivalued dependencies. We can manage with such reasoning for very simple multivalued dependencies, which seem to be most common in practice For complex dependencies, it is better to reason about sets of dependencies using a system of inference rules (see Appendix C). ...
... dependencies and multivalued dependencies. We can manage with such reasoning for very simple multivalued dependencies, which seem to be most common in practice For complex dependencies, it is better to reason about sets of dependencies using a system of inference rules (see Appendix C). ...
eCommerce&Security - DCU School of Computing
... • Active set and current row: + a set of tuples from a SELECT is called the active set + at any time we can only work with one tuple in the active set, called the current row ...
... • Active set and current row: + a set of tuples from a SELECT is called the active set + at any time we can only work with one tuple in the active set, called the current row ...
Object Database Systems
... created in our minds mechanisms enabling us to isolate objects in our environment, to name them, and to assign to them some properties and behaviour. Objectorientedness in computer technologies, from the psychological point of view, is founded on inborn mechanisms of our minds, as the idea of a comp ...
... created in our minds mechanisms enabling us to isolate objects in our environment, to name them, and to assign to them some properties and behaviour. Objectorientedness in computer technologies, from the psychological point of view, is founded on inborn mechanisms of our minds, as the idea of a comp ...
GIS and Remote Sensing in Water Resources Management
... set of last name, first name and address. non redundancy ; any key attribute selected and tabulated should keep the key's uniqueness. e.g. address can not be dropped from telephone address, because there may be many with the same names. Prime attribute : an attribute listed in at least one key. The ...
... set of last name, first name and address. non redundancy ; any key attribute selected and tabulated should keep the key's uniqueness. e.g. address can not be dropped from telephone address, because there may be many with the same names. Prime attribute : an attribute listed in at least one key. The ...
Schema Fragmentation
... model for the table access. One possible model would be to give for every single tuple the frequency of access of a specific application, as illustrated in the histogram on the right. Since we do however not consider fragmentation of a table into single tuples, this description is at a too fine gran ...
... model for the table access. One possible model would be to give for every single tuple the frequency of access of a specific application, as illustrated in the histogram on the right. Since we do however not consider fragmentation of a table into single tuples, this description is at a too fine gran ...
Cooperative query an..
... Responses to queries posed by a user of a database do not always contain the information required DB and information systems are often hard to use because they do not explicitly attempt to cooperate with their users. They answer literally the queries posed to them A user might need more information ...
... Responses to queries posed by a user of a database do not always contain the information required DB and information systems are often hard to use because they do not explicitly attempt to cooperate with their users. They answer literally the queries posed to them A user might need more information ...
Cooperative Query
... Responses to queries posed by a user of a database do not always contain the information required DB and information systems are often hard to use because they do not explicitly attempt to cooperate with their users. They answer literally the queries posed to them A user might need more information ...
... Responses to queries posed by a user of a database do not always contain the information required DB and information systems are often hard to use because they do not explicitly attempt to cooperate with their users. They answer literally the queries posed to them A user might need more information ...
IS 431-451 - NJIT: Course Schedule
... principles are emphasized throughout the course, beginning with high level descriptions of relational databases using data modeling tools (such as ER (Entity Relationship) diagrams) and progressing to relational database design principles based on higher order normalizations. We will examine some po ...
... principles are emphasized throughout the course, beginning with high level descriptions of relational databases using data modeling tools (such as ER (Entity Relationship) diagrams) and progressing to relational database design principles based on higher order normalizations. We will examine some po ...
