Chapter 12 - Personal Web Pages
... Each operator typically implemented using a `pull’ interface: when an operator is `pulled’ for the next output tuples, it `pulls’ on its inputs and computes them. ...
... Each operator typically implemented using a `pull’ interface: when an operator is `pulled’ for the next output tuples, it `pulls’ on its inputs and computes them. ...
Optimization_Lecture_7
... Selection using Hash Index • For a general selection query: R.attr op value (R), hash index is best if R.attr is equality (=). It is not good for not equality (e.g. <, >, <>). • We retrieve the index page that contain the rids (record identifiers) of the qualifying tuples. • Then the pages that co ...
... Selection using Hash Index • For a general selection query: R.attr op value (R), hash index is best if R.attr is equality (=). It is not good for not equality (e.g. <, >, <>). • We retrieve the index page that contain the rids (record identifiers) of the qualifying tuples. • Then the pages that co ...
Talk Slides - The Stanford University InfoLab
... (3) Account number, credit or debit card number, in combination with any required security code…” ...
... (3) Account number, credit or debit card number, in combination with any required security code…” ...
Relational Data Model
... Referential integrity is violated if the referenced tuple does not exist in the appropriate relation – A tuple (123456789, MGT123, F1994) in TEACHING relation violates referential integrity constraint because there is no tuple with Id = 123456789 in PROFESSOR relation ...
... Referential integrity is violated if the referenced tuple does not exist in the appropriate relation – A tuple (123456789, MGT123, F1994) in TEACHING relation violates referential integrity constraint because there is no tuple with Id = 123456789 in PROFESSOR relation ...
SQL – The Director`s Cut
... A letter to the editor • EDIT • Take a mental break between writing and editing • Be critical • Do I even need to do this at all ...
... A letter to the editor • EDIT • Take a mental break between writing and editing • Be critical • Do I even need to do this at all ...
Week 7 Table Analysis
... such that there are multiple records per entry) Split the tables, so that all non-key attributes depend on a primary key. Split tables further, if there are transitive functional dependencies. This results in tables with a single, primary key per table. ...
... such that there are multiple records per entry) Split the tables, so that all non-key attributes depend on a primary key. Split tables further, if there are transitive functional dependencies. This results in tables with a single, primary key per table. ...
Data base management system
... Design of ER schema, Reduction of ER schema to tables. Domains, Relations & Keys: Domains, Relations, Kinds of relations, Relational databases, Various types of keys: candidate, primary, alternate & foreign keys. Relation Algebra & SQL: The structure, Relational algebra with extended operations, Mod ...
... Design of ER schema, Reduction of ER schema to tables. Domains, Relations & Keys: Domains, Relations, Kinds of relations, Relational databases, Various types of keys: candidate, primary, alternate & foreign keys. Relation Algebra & SQL: The structure, Relational algebra with extended operations, Mod ...
$doc.title
... – If attribute A in relation R has the same domain as attribute B in relation S, and B is a key (or component of a key) for S, then whenever t1 is a tuple in R with t[A] = x, then there must exist a tuple t2 in S with t2[B] = x. – I.e., you can't refer to something that doesn't exist. – The att ...
... – If attribute A in relation R has the same domain as attribute B in relation S, and B is a key (or component of a key) for S, then whenever t1 is a tuple in R with t[A] = x, then there must exist a tuple t2 in S with t2[B] = x. – I.e., you can't refer to something that doesn't exist. – The att ...
Midterm Exam Chapters 1,2,3,5, 6,7 (closed book)
... Chapter 3: Relational Model • Basic concepts: relation and tuple • Create relations using SQL • create relations • add and delete tuples • specify constraints: primary key constraint, referential integrity constraint • create views ...
... Chapter 3: Relational Model • Basic concepts: relation and tuple • Create relations using SQL • create relations • add and delete tuples • specify constraints: primary key constraint, referential integrity constraint • create views ...
Advanced SQL lecture
... these can be queried like any table DBA_TABLES – descriptions of tables DBA_CONSTRAINTS – description of constraints DBA_USERS – information about the users of the system DBA_TAB_PRIVS – descriptions of grants on objects in the ...
... these can be queried like any table DBA_TABLES – descriptions of tables DBA_CONSTRAINTS – description of constraints DBA_USERS – information about the users of the system DBA_TAB_PRIVS – descriptions of grants on objects in the ...
Infrastructure
... attributes are all the E-R attributes of E. Then each tuple represents one entity of E. To represent relation R between entity sets E1, …, Ek, create relation R with key attributes of E1, …, key attributes of Ek, as attributes (rename duplicates). Each tuple of the relation represents one combinati ...
... attributes are all the E-R attributes of E. Then each tuple represents one entity of E. To represent relation R between entity sets E1, …, Ek, create relation R with key attributes of E1, …, key attributes of Ek, as attributes (rename duplicates). Each tuple of the relation represents one combinati ...
IT360 12 week Exam Review Sheet 1. PHP
... a. A stored procedure is a program that performs some common action on database data and is stored in the database. b. Advantages of stored procedures c. How to write a stored procedure ...
... a. A stored procedure is a program that performs some common action on database data and is stored in the database. b. Advantages of stored procedures c. How to write a stored procedure ...
9-20-2006-overview
... Many databases are not crawlable Often a search interface is available, with existing keyword index How to identify “useful” documents? ...
... Many databases are not crawlable Often a search interface is available, with existing keyword index How to identify “useful” documents? ...
databases and markup languages
... actors working for him? – In which years films have been shot that starred actors born between 1926 and 1935? ...
... actors working for him? – In which years films have been shot that starred actors born between 1926 and 1935? ...
ppt
... • Database translates SQL to one or more Relational Algebra plans • Plan is a tree of operations, with access path for each • Access path is how each operator gets tuples – If working directly on table, can use scan, index – Some operators, like sort-merge join, or group-by, need tuples sorted – Oft ...
... • Database translates SQL to one or more Relational Algebra plans • Plan is a tree of operations, with access path for each • Access path is how each operator gets tuples – If working directly on table, can use scan, index – Some operators, like sort-merge join, or group-by, need tuples sorted – Oft ...
OWL2 based Data Cleansing Using Conditional Exclusion Dependencies
... An exclusion dependency (ED) [1] corresponds to forbidding the appearance of a given tuple in a relation S when a tuple appears in a relation R and is represented as the following axiom: ∀x, y, z, x0 , z 0 R(x, y, z) → ¬S(x0 , x, z 0 ). A conditional extension of an ED forbids the appearance of tupl ...
... An exclusion dependency (ED) [1] corresponds to forbidding the appearance of a given tuple in a relation S when a tuple appears in a relation R and is represented as the following axiom: ∀x, y, z, x0 , z 0 R(x, y, z) → ¬S(x0 , x, z 0 ). A conditional extension of an ED forbids the appearance of tupl ...
Exam Discussion-AIC
... v V (v[k ] s[k ] l L( l[ d ] v[d ] l[ b] s[b])))} • Suppose there are 2 beers a, b, 1 bar k, 2 drinkers x, y; everyone serves/visits/likes everything Then the correct answer should result in {a, b}. The tupel calculus expression does not contain a, because every visitor of k also like ...
... v V (v[k ] s[k ] l L( l[ d ] v[d ] l[ b] s[b])))} • Suppose there are 2 beers a, b, 1 bar k, 2 drinkers x, y; everyone serves/visits/likes everything Then the correct answer should result in {a, b}. The tupel calculus expression does not contain a, because every visitor of k also like ...