The Relational Model - Department of Computer Science | UNC
... A set of fields is a key for a relation if : 1. No two distinct tuples can have same values in all key fields, and 2. This is not true for any subset of the key. – Part 2 false? A superkey. – If there’s >1 key for a relation, one of the keys is chosen (by DBA) to be the primary key. ...
... A set of fields is a key for a relation if : 1. No two distinct tuples can have same values in all key fields, and 2. This is not true for any subset of the key. – Part 2 false? A superkey. – If there’s >1 key for a relation, one of the keys is chosen (by DBA) to be the primary key. ...
CS122_SUMMER_2009_LECTURE_09a
... INSERT INTO and Subqueries As in the previous example, subqueries in the INSERT command work, but only if the update table and the subquery table are different. This rule only applies to MySQL, other database management systems may behave differently. ...
... INSERT INTO and Subqueries As in the previous example, subqueries in the INSERT command work, but only if the update table and the subquery table are different. This rule only applies to MySQL, other database management systems may behave differently. ...
Cracking the Database Store
... inevitably touch many tuples of no interest. Although the access structures often permit a partial predicate evaluation, it is only after the complete predicate evaluation that we know which access was in vain. In this paper we explore a different route based on the hypothesis that access maintenanc ...
... inevitably touch many tuples of no interest. Although the access structures often permit a partial predicate evaluation, it is only after the complete predicate evaluation that we know which access was in vain. In this paper we explore a different route based on the hypothesis that access maintenanc ...
Read Chapter 2.1
... enterprise. Common choices include: Entity vs. attribute, entity vs. relationship, binary or n-ary relationship, whether or not to use ISA hierarchies, and whether or not to use ...
... enterprise. Common choices include: Entity vs. attribute, entity vs. relationship, binary or n-ary relationship, whether or not to use ISA hierarchies, and whether or not to use ...
SEAS VLDB - Microsoft
... Recommendation: For large tables use 10% sampling, but you must test and try different values. The right answer could be 5% or 50%. SEAS06 - VLDB Management & Operation ...
... Recommendation: For large tables use 10% sampling, but you must test and try different values. The right answer could be 5% or 50%. SEAS06 - VLDB Management & Operation ...
ADT Parameter in Connection URL and ASU
... Whenever a user requests a connection to the server for query execution, the server management components creates a new user connection for the user. Execution of query is performed under the newly established user connection. The user connection runs in its own operating system thread, within the s ...
... Whenever a user requests a connection to the server for query execution, the server management components creates a new user connection for the user. Execution of query is performed under the newly established user connection. The user connection runs in its own operating system thread, within the s ...
Chapter 14: Query Optimization
... bushy trees is O(3n). With n = 10, this number is 59000 instead of 176 billion! Space complexity is O(2n) To find best left-deep join tree for a set of n relations: Consider n alternatives with one relation as right-hand side input and the other relations as left-hand side input. Modify optimi ...
... bushy trees is O(3n). With n = 10, this number is 59000 instead of 176 billion! Space complexity is O(2n) To find best left-deep join tree for a set of n relations: Consider n alternatives with one relation as right-hand side input and the other relations as left-hand side input. Modify optimi ...
Chapter 14: Query Optimization
... bushy trees is O(3n). With n = 10, this number is 59000 instead of 176 billion! Space complexity is O(2n) To find best left-deep join tree for a set of n relations: Consider n alternatives with one relation as right-hand side input and the other relations as left-hand side input. Modify optimi ...
... bushy trees is O(3n). With n = 10, this number is 59000 instead of 176 billion! Space complexity is O(2n) To find best left-deep join tree for a set of n relations: Consider n alternatives with one relation as right-hand side input and the other relations as left-hand side input. Modify optimi ...
Explanation-Based Auditing
... a clinical appointment may be granted access to patient records.) Unfortunately, in environments like hospitals, it is very difficult to specify and maintain detailed access control policies [2]. (For example, residents and medical students change departments as often as once per week.) Further, ove ...
... a clinical appointment may be granted access to patient records.) Unfortunately, in environments like hospitals, it is very difficult to specify and maintain detailed access control policies [2]. (For example, residents and medical students change departments as often as once per week.) Further, ove ...
(ASM) Pocket Reference Guide
... v$asm_file Lists all files that belong to diskgroups mounted by the ASM instance v$asm_operation Reports information about current active operations. Rebalance activity is reported in this view v$asm_template Lists all the templates currently mounted by the ASM instance v$asm_diskgroup_stat same as ...
... v$asm_file Lists all files that belong to diskgroups mounted by the ASM instance v$asm_operation Reports information about current active operations. Rebalance activity is reported in this view v$asm_template Lists all the templates currently mounted by the ASM instance v$asm_diskgroup_stat same as ...
Computing Consistent Query Answers using Conflict
... • Encouraging experimental results that compare our approach with an approach based on query rewriting and estimate the overhead of computing consistent query answers. No comprehensive results of this kind exist in the literature. Because our query language includes union, our approach can extract i ...
... • Encouraging experimental results that compare our approach with an approach based on query rewriting and estimate the overhead of computing consistent query answers. No comprehensive results of this kind exist in the literature. Because our query language includes union, our approach can extract i ...
Using ADO from Delphi
... and delete some records but not physically. ........................................................... 102 How do I retrieve a system information, for example, list of tables, fields (columns), indexes from the database? .............................................................................. ...
... and delete some records but not physically. ........................................................... 102 How do I retrieve a system information, for example, list of tables, fields (columns), indexes from the database? .............................................................................. ...
select
... Chapter 3: SQL Basics Information Technology Department Bryar Hassan (MSc Eng.) [email protected] ...
... Chapter 3: SQL Basics Information Technology Department Bryar Hassan (MSc Eng.) [email protected] ...
Oracle Database Appliance Sales Jarosław Skibiński
... using the very best of breed of products, AND it comes fully integrated so you don’t need to spend the time and money on alternative approaches, or assume the risk of not designing it correctly. The exclusive Oracle Appliance Manager software provides unprecedented ease of implementation and managem ...
... using the very best of breed of products, AND it comes fully integrated so you don’t need to spend the time and money on alternative approaches, or assume the risk of not designing it correctly. The exclusive Oracle Appliance Manager software provides unprecedented ease of implementation and managem ...
Indexing Semistructured Data - Stanford InfoLab
... where exists A in M.Actor : exists N in A.Name : N = \Harrison Ford" The most straightforward approach is to rst consider the from clause, nding objects along the path DB.Movie.Title. Then, for each Movie, we look for the existence of a path Actor.Name whose value is \Harrison Ford". We call this ...
... where exists A in M.Actor : exists N in A.Name : N = \Harrison Ford" The most straightforward approach is to rst consider the from clause, nding objects along the path DB.Movie.Title. Then, for each Movie, we look for the existence of a path Actor.Name whose value is \Harrison Ford". We call this ...
PPT
... Impose partial ordering of all data items and require that a transaction can lock data items only in the order specified by the partial order (graph-based protocol). ...
... Impose partial ordering of all data items and require that a transaction can lock data items only in the order specified by the partial order (graph-based protocol). ...
A Coq Formalization of the Relational Data Model
... Our long term purpose is to prove that existing systems conform to their specifications and to verify that programs that make intensive use of database queries are correct and not to implement a RDBMS in Coq. So, the first essential step is to formalize the relational model of data. We first formali ...
... Our long term purpose is to prove that existing systems conform to their specifications and to verify that programs that make intensive use of database queries are correct and not to implement a RDBMS in Coq. So, the first essential step is to formalize the relational model of data. We first formali ...
Database Configuration - L-Soft
... CREATE TABLE privilege and a sufficiently large tablespace quota in the user's default tablespace. Again, remember that you can only use an existing Oracle database with Maestro User Interface if the database uses the UTF-8 character set. Note that the Maestro User Interface does not require unusual ...
... CREATE TABLE privilege and a sufficiently large tablespace quota in the user's default tablespace. Again, remember that you can only use an existing Oracle database with Maestro User Interface if the database uses the UTF-8 character set. Note that the Maestro User Interface does not require unusual ...
Document in
... This leads to the conclusion that abstracting information from a multimedia artifact is not enough and we also should have some provision to be able to specify operations on artifacts that can be executed at run time. 3.2. ACCESS STRUCTURE GENERATION: Using feature & concept values the system create ...
... This leads to the conclusion that abstracting information from a multimedia artifact is not enough and we also should have some provision to be able to specify operations on artifacts that can be executed at run time. 3.2. ACCESS STRUCTURE GENERATION: Using feature & concept values the system create ...
ch15
... A lock manager can be implemented as a separate process to which transactions send lock and unlock requests The lock manager replies to a lock request by sending a lock grant messages (or a message asking the transaction to roll back, in case of a deadlock) The requesting transaction waits until its ...
... A lock manager can be implemented as a separate process to which transactions send lock and unlock requests The lock manager replies to a lock request by sending a lock grant messages (or a message asking the transaction to roll back, in case of a deadlock) The requesting transaction waits until its ...
AND OUTLINES OF TESTS,
... 1. Henry F. Korth, Abraham, "Database System Concepts", Tata McGraw Hill. 2. Naveen Prakash, Introduction to Database Management”, TMH, 1993. 3. C.J. Date, "An Introduction to Data Base Systems", Pearsoned Education India. ...
... 1. Henry F. Korth, Abraham, "Database System Concepts", Tata McGraw Hill. 2. Naveen Prakash, Introduction to Database Management”, TMH, 1993. 3. C.J. Date, "An Introduction to Data Base Systems", Pearsoned Education India. ...
Slides from Lecture 19 - Courses - University of California, Berkeley
... records of S.F. Bay Area streets along with the 70,000-records from the USGS GNIS database. California Dams is a database of information about the 1395 dams under state jurisdiction. An additional 11 GB of geographical data represents maps and imagery that have been processed for inclusion as layers ...
... records of S.F. Bay Area streets along with the 70,000-records from the USGS GNIS database. California Dams is a database of information about the 1395 dams under state jurisdiction. An additional 11 GB of geographical data represents maps and imagery that have been processed for inclusion as layers ...