Consistent Query Answers in Inconsistent Databases
... Data warehousing. A data warehouse contains data coming from many different sources. Some of it typically does not satisfy the given integrity constraints. The usual approach is thus to clean the data by removing inconsistencies before the data is stored in the warehouse [6]. Our results make it pos ...
... Data warehousing. A data warehouse contains data coming from many different sources. Some of it typically does not satisfy the given integrity constraints. The usual approach is thus to clean the data by removing inconsistencies before the data is stored in the warehouse [6]. Our results make it pos ...
Slide 1
... HDF5/PDF • Both HDF5 and PDF formats are published and open • Both can include heterogeneous types of information • PDF focused on documents • HDF5 focused on collections of different types, with strong support for multi-dimensional arrays of numeric data ...
... HDF5/PDF • Both HDF5 and PDF formats are published and open • Both can include heterogeneous types of information • PDF focused on documents • HDF5 focused on collections of different types, with strong support for multi-dimensional arrays of numeric data ...
DataGuides: Enabling Query Formulation and
... Our work is cast in the context of the Lore system. All data in Lore follows a simple, graph-based data model called OEM, for Object Exchange Model [PGW95]. Thus, our work can be applied easily to any graph-based data model. A Lore database is queried using Lorel [AQM+96], an OQL-based language desi ...
... Our work is cast in the context of the Lore system. All data in Lore follows a simple, graph-based data model called OEM, for Object Exchange Model [PGW95]. Thus, our work can be applied easily to any graph-based data model. A Lore database is queried using Lorel [AQM+96], an OQL-based language desi ...
Entity Sets
... Although it is possible to replace any nonbinary (n-ary, for n > 2) relationship set by a number of distinct binary relationship sets, a n-ary relationship set shows more clearly that several entities participate in a single relationship. Placement of relationship attributes ...
... Although it is possible to replace any nonbinary (n-ary, for n > 2) relationship set by a number of distinct binary relationship sets, a n-ary relationship set shows more clearly that several entities participate in a single relationship. Placement of relationship attributes ...
Aptitude Questions 1. One guy has Rs. 100/
... (C) The code complies but results in run-time exception (D) "The date of joining is ". ( The date is null) 4. As far as handling null values in JAVA and SQL is concerned which of the following statements is wrong? (A) For Java Objects SQL NULL maps to JAVA NULL (B) While using the method getInt( ), ...
... (C) The code complies but results in run-time exception (D) "The date of joining is ". ( The date is null) 4. As far as handling null values in JAVA and SQL is concerned which of the following statements is wrong? (A) For Java Objects SQL NULL maps to JAVA NULL (B) While using the method getInt( ), ...
Transferring Data with DB Connect
... initiating a BW Application Server from the SAP kernel. From now on, this connection is referred to as the (SAP) default connection. All SQL commands- irrespective of whether Open or Native SQL- submitted by the SAP kernel or ABAP programs, automatically relate to this default connection. That is, t ...
... initiating a BW Application Server from the SAP kernel. From now on, this connection is referred to as the (SAP) default connection. All SQL commands- irrespective of whether Open or Native SQL- submitted by the SAP kernel or ABAP programs, automatically relate to this default connection. That is, t ...
Why Migrate from MySQL to Cassandra? White Paper BY DATASTAX CORPORATION June 2012
... Multi-data center replication – Whether it’s keeping data in multiple locations for disaster recovery scenarios or locating data physically near its end users for fast performance, Cassandra offers support for multiple data centers. Administrators simply configure how many copies of the data they wa ...
... Multi-data center replication – Whether it’s keeping data in multiple locations for disaster recovery scenarios or locating data physically near its end users for fast performance, Cassandra offers support for multiple data centers. Administrators simply configure how many copies of the data they wa ...
5-Semanticx - Extra Materials
... ➡ Following the “no read up” rule, a read query from the same subject can be ...
... ➡ Following the “no read up” rule, a read query from the same subject can be ...
Kit - Nordic Backup
... • Retrieval of data from a crashed hard drive is often extremely costly, and there is NO GUARANTEE of success! • Your business data go hand in hand with your business operations. The loss of such data, or even their temporary inaccessibility, may threaten your hardearned competitive position. ...
... • Retrieval of data from a crashed hard drive is often extremely costly, and there is NO GUARANTEE of success! • Your business data go hand in hand with your business operations. The loss of such data, or even their temporary inaccessibility, may threaten your hardearned competitive position. ...
Formal Technical Reviews
... Used to enforce multilevel security by classifying data and users into various security classes or levels and then implement the appropriate security policy ...
... Used to enforce multilevel security by classifying data and users into various security classes or levels and then implement the appropriate security policy ...
A Field Guide to Hadoop
... • Others. NoSQL databases generally do not support relational join operations, complex transactions, or foreign key constraints common in relational systems, but generally scale better to large amounts of data. You’ll have to decide what works best for your data sets and the information you ...
... • Others. NoSQL databases generally do not support relational join operations, complex transactions, or foreign key constraints common in relational systems, but generally scale better to large amounts of data. You’ll have to decide what works best for your data sets and the information you ...
Reading Report 2 - Informatics Homepages Server
... (1) Build an access plan for every table involved in the query. If Table A is replicated at sites S1 and S2, enumerate scan(A, S1) and scan(A, S2) as alternative access plans for Table A. (2) Enumerate all two-way join plans using the access plans as building blocks. also enumerate alternative join ...
... (1) Build an access plan for every table involved in the query. If Table A is replicated at sites S1 and S2, enumerate scan(A, S1) and scan(A, S2) as alternative access plans for Table A. (2) Enumerate all two-way join plans using the access plans as building blocks. also enumerate alternative join ...
Triggers
... 2 Database Triggers in SQL 3 Using Database Triggers for Information Processing within DBMS 4 Restrictions for Database Triggers ...
... 2 Database Triggers in SQL 3 Using Database Triggers for Information Processing within DBMS 4 Restrictions for Database Triggers ...
Understanding and Selecting a Database Activity
... select query on a credit card column which returns more than 5 results. ...
... select query on a credit card column which returns more than 5 results. ...
Structured Query Language (SQL) Advanced Features
... calculation on the values in a set of selected rows Expression specified for AVG and SUM functions must result in a numeric value. The expression for Min, MAX, and COUNT can result in a numeric, date, or string value By default all values are included in the calculation regardless of whether they ar ...
... calculation on the values in a set of selected rows Expression specified for AVG and SUM functions must result in a numeric value. The expression for Min, MAX, and COUNT can result in a numeric, date, or string value By default all values are included in the calculation regardless of whether they ar ...
Chapter 4 Using Database Management Systems
... It takes time and skill to create a properly working database. Well-educated professionals design and build the databases used by corporations, non-profit organizations, and governmental agencies. To do so requires years of training in both database management software and the underlying mathematics ...
... It takes time and skill to create a properly working database. Well-educated professionals design and build the databases used by corporations, non-profit organizations, and governmental agencies. To do so requires years of training in both database management software and the underlying mathematics ...
basic application software - McGraw
... time in the future. They point out that Web-based applications offer advantages beyond universal access to software and to data. One advantage is that users may no longer need to upgrade software on their hard disk when a new version becomes available. Of course, there are some potential disadvantag ...
... time in the future. They point out that Web-based applications offer advantages beyond universal access to software and to data. One advantage is that users may no longer need to upgrade software on their hard disk when a new version becomes available. Of course, there are some potential disadvantag ...
Outline
... unique value in its primary-key field • Compound Primary key: when a record has a unique key based on a combination of two fields • Foreign key: – Field for which every entry has a unique value in another table and where the field in the other table is the primary key for that table – Rule of Refere ...
... unique value in its primary-key field • Compound Primary key: when a record has a unique key based on a combination of two fields • Foreign key: – Field for which every entry has a unique value in another table and where the field in the other table is the primary key for that table – Rule of Refere ...
2_Managing external data_2
... • SQL’s heritage as a tuple calculus language shows • tuple variables are useful when one relation is used “twice” in a query: ...
... • SQL’s heritage as a tuple calculus language shows • tuple variables are useful when one relation is used “twice” in a query: ...
chapter19
... transaction must persist despite failures. Isolation : if between steps 3 and 6, another transaction is allowed to access the partially updated database, it will see an inconsistent database. ACID properties can be ensured by running the transactions serially. However, loose the benefits of executin ...
... transaction must persist despite failures. Isolation : if between steps 3 and 6, another transaction is allowed to access the partially updated database, it will see an inconsistent database. ACID properties can be ensured by running the transactions serially. However, loose the benefits of executin ...
Policy-Based Management of SQL Servers and Databases
... Database mirroring protects the database access by providing manual or automatic failover when the principal server fails. To provide additional access to the data, you can configure the mirror server with a database snapshot that allows read-only access to the mirror copy. A data page can become co ...
... Database mirroring protects the database access by providing manual or automatic failover when the principal server fails. To provide additional access to the data, you can configure the mirror server with a database snapshot that allows read-only access to the mirror copy. A data page can become co ...
Week 9 - Purdue Engineering
... – An n-ary relationship set R relates n entity sets E1 ... En; each relationship R is a set of n tuples (e1,…,en) such that e1 ∈ E1, ..., en ∈ En u Same entity set could participate in different relationship sets, or in different “roles” in same set. ...
... – An n-ary relationship set R relates n entity sets E1 ... En; each relationship R is a set of n tuples (e1,…,en) such that e1 ∈ E1, ..., en ∈ En u Same entity set could participate in different relationship sets, or in different “roles” in same set. ...