Database Fundamentals
... – The software components include the operating system (O/S), the database engine (DBMS) and the additional tools including application and utility software. • The operating system refers to the software that makes all the resources available to users. The resources usually include hardware such as ...
... – The software components include the operating system (O/S), the database engine (DBMS) and the additional tools including application and utility software. • The operating system refers to the software that makes all the resources available to users. The resources usually include hardware such as ...
PPT
... Also supports metadata retrieval, such as querying about relations present in the database and the names and types of relation attributes ...
... Also supports metadata retrieval, such as querying about relations present in the database and the names and types of relation attributes ...
Transactions
... with transactions programmatically • JTS is the vendor implementation of transaction management in Java – JTS is a Java mapping of CORBA's Object Transaction Service (OTS) – sometimes you see references to JTS/OTS – this is why © Copyright UTS Faculty of Information Technology – Transactions ...
... with transactions programmatically • JTS is the vendor implementation of transaction management in Java – JTS is a Java mapping of CORBA's Object Transaction Service (OTS) – sometimes you see references to JTS/OTS – this is why © Copyright UTS Faculty of Information Technology – Transactions ...
ADVANCED SQL AND PL/SQL TOPICS
... • Multiple instances can run concurrently on the same computer, each accessing its own physical database • Security for database startup and shutdown is controlled through connections to Oracle with administrator privileges. Normal users do not have control over the current status of an Oracle datab ...
... • Multiple instances can run concurrently on the same computer, each accessing its own physical database • Security for database startup and shutdown is controlled through connections to Oracle with administrator privileges. Normal users do not have control over the current status of an Oracle datab ...
presentation source - Courses
... database, DA and DBA are responsible for developing procedures that ensure the integrity and security of the database during the update process. • Specific responsibility for data collection, editing and verification must be assigned • Quality assurance must be practiced to protect and audit the dat ...
... database, DA and DBA are responsible for developing procedures that ensure the integrity and security of the database during the update process. • Specific responsibility for data collection, editing and verification must be assigned • Quality assurance must be practiced to protect and audit the dat ...
Row Locks - Webcourse
... • Locks are used in DB to permit concurrent access to shared resources, while at the same time providing data integrity and consistency. • Oracle locks table data at the row level but also uses locks to provide concurrent access to various resources like stored procedure • Locks achieve the followin ...
... • Locks are used in DB to permit concurrent access to shared resources, while at the same time providing data integrity and consistency. • Oracle locks table data at the row level but also uses locks to provide concurrent access to various resources like stored procedure • Locks achieve the followin ...
slides
... – if Tt < Dr, abort T (can't write something read by later transaction) – else if Tt < Dw, ignore [Thomas Write Rule] (already overwritten. Note: for blind writes only; most updates are a read+write) – else Dw Tt [shows it was written by T] ...
... – if Tt < Dr, abort T (can't write something read by later transaction) – else if Tt < Dw, ignore [Thomas Write Rule] (already overwritten. Note: for blind writes only; most updates are a read+write) – else Dw Tt [shows it was written by T] ...
SQL Server Administrative Duties
... In relational-database design theory, normalization rules identify certain attributes that must be present or absent in a well-designed database. A complete discussion of normalization rules goes well beyond the scope of this topic. However, there are a few rules that can help you achieve a sound ...
... In relational-database design theory, normalization rules identify certain attributes that must be present or absent in a well-designed database. A complete discussion of normalization rules goes well beyond the scope of this topic. However, there are a few rules that can help you achieve a sound ...
SQLite - Introduction
... Since SQLite reads and writes an ordinary disk file, the only access permissions that can be applied are the normal file access permissions of the underlying operating system. The GRANT and REVOKE commands commonly found on client/server RDBMSes are not implemented because they would be meaningless ...
... Since SQLite reads and writes an ordinary disk file, the only access permissions that can be applied are the normal file access permissions of the underlying operating system. The GRANT and REVOKE commands commonly found on client/server RDBMSes are not implemented because they would be meaningless ...
Distributed Database Systems
... sites at which it executes are subordinates. When an Xact wants to commit: { Coordinator sends prepare msg to each subordinate. | Subordinate force-writes an abort or prepare log record and then sends a no or yes msg to coordinator. } If coordinator gets unanimous yes votes, force-writes a commit lo ...
... sites at which it executes are subordinates. When an Xact wants to commit: { Coordinator sends prepare msg to each subordinate. | Subordinate force-writes an abort or prepare log record and then sends a no or yes msg to coordinator. } If coordinator gets unanimous yes votes, force-writes a commit lo ...
Distributed Databases
... Comments on 2PC Two rounds of communication: first, voting; then, termination. Both initiated by coordinator. Any site can decide to abort an Xact. Every msg reflects a decision by the sender; to ensure that this decision survives failures, it is first recorded in the local log. All commit pr ...
... Comments on 2PC Two rounds of communication: first, voting; then, termination. Both initiated by coordinator. Any site can decide to abort an Xact. Every msg reflects a decision by the sender; to ensure that this decision survives failures, it is first recorded in the local log. All commit pr ...
slides
... When a transaction fails, all modifications made during that transaction are undone. That may not be what you want! – Suppose you want to add an audit record every time someone tries to make some specific kind of change. – You want to add that audit record even if the ...
... When a transaction fails, all modifications made during that transaction are undone. That may not be what you want! – Suppose you want to add an audit record every time someone tries to make some specific kind of change. – You want to add that audit record even if the ...
Chapter 09 Presentation
... – Locks are obtained throughout the transaction – No lock is released until the COMMIT or ROLLBACK command is issued – This strategy is more restrictive but easier to implement than two-phase locking Copyright © 2004 Database Processing: Fundamentals, Design, and Implementation, 9/e by David M. Kroe ...
... – Locks are obtained throughout the transaction – No lock is released until the COMMIT or ROLLBACK command is issued – This strategy is more restrictive but easier to implement than two-phase locking Copyright © 2004 Database Processing: Fundamentals, Design, and Implementation, 9/e by David M. Kroe ...
Database manipulation using Models classes
... CRUD = create ,read, update, delete). NOTE: we will use default SQLite3 (filebased) that you can simply install as a gem (via > gem install sqlite3) on the ...
... CRUD = create ,read, update, delete). NOTE: we will use default SQLite3 (filebased) that you can simply install as a gem (via > gem install sqlite3) on the ...
A Comparative Study on Oracle and IBM
... information to prevent it from changing while being read, or to prevent queries from reading changed but uncommitted information, Oracle uses the current information in the undo records to construct a read-consistent view of a table's data, and to ensure that a consistent version of the information ...
... information to prevent it from changing while being read, or to prevent queries from reading changed but uncommitted information, Oracle uses the current information in the undo records to construct a read-consistent view of a table's data, and to ensure that a consistent version of the information ...
Oracle Database Brief History
... An object relational database management system ( ORDBMS) extends the capabilities of the RDBMS to support object-oriented concepts.You can use ORACLE as an RDBMS or take advantage of its object oriented features. There are three flavors of ORACLE: ...
... An object relational database management system ( ORDBMS) extends the capabilities of the RDBMS to support object-oriented concepts.You can use ORACLE as an RDBMS or take advantage of its object oriented features. There are three flavors of ORACLE: ...
Slides from Lecture 15 - Courses - University of California, Berkeley
... • The goal is to support access by multiple users to the same data, at the same time • It must assure that the transactions are serializable and that they are isolated • It is intended to handle several problems in an uncontrolled system • Specifically: – Lost updates – Inconsistent data states duri ...
... • The goal is to support access by multiple users to the same data, at the same time • It must assure that the transactions are serializable and that they are isolated • It is intended to handle several problems in an uncontrolled system • Specifically: – Lost updates – Inconsistent data states duri ...
An Integrated Approach to Recovery and High Availability in an Updatable, Distributed Data Warehouse
... and recovery to ensure transactional semantics. One commonly used approach is to implement snapshot isolation [4], which allows read-only queries to avoid setting any locks by having them read a historical snapshot of the database starting from some point in recent history. In such updatable environ ...
... and recovery to ensure transactional semantics. One commonly used approach is to implement snapshot isolation [4], which allows read-only queries to avoid setting any locks by having them read a historical snapshot of the database starting from some point in recent history. In such updatable environ ...
3. Crosscutting Concerns in Database Systems
... while for another physical conversion may be essential. The choice is dictated by “local” organisational needs and at times custom variations of standard instance adaptation models can be required. The choice of instance adaptation approach may even vary from one application to another within the sa ...
... while for another physical conversion may be essential. The choice is dictated by “local” organisational needs and at times custom variations of standard instance adaptation models can be required. The choice of instance adaptation approach may even vary from one application to another within the sa ...
Kroenke-DBP-e10-PPT-Chapter09-Part02
... • Consistency means either statement level or transaction level consistency – Statement level consistency: each statement independently processes rows consistently – Transaction level consistency: all rows impacted by either of the SQL statements are protected from changes during the entire transact ...
... • Consistency means either statement level or transaction level consistency – Statement level consistency: each statement independently processes rows consistently – Transaction level consistency: all rows impacted by either of the SQL statements are protected from changes during the entire transact ...
Python sqlite3
... This method rolls back any changes to the database since the last call to commit(). conn.execute("UPDATE COMPANY set SALARY = 25000.00 where ID=1") conn.commit conn.execute("DELETE from COMPANY where ID=2;") conn.commit connection.total_changes() This routine returns the total number of database row ...
... This method rolls back any changes to the database since the last call to commit(). conn.execute("UPDATE COMPANY set SALARY = 25000.00 where ID=1") conn.commit conn.execute("DELETE from COMPANY where ID=2;") conn.commit connection.total_changes() This routine returns the total number of database row ...
Query Answering Under Exact View Assumption in Local As View
... – G is the global schema expressed in the relational model with integrity constraints. Henceforth, we indicate with AG the alphabet of the relation symbols of G and with CG the set of integrity constraints specified on AG . – S is the source schema, constituted by the schemata of the various sources ...
... – G is the global schema expressed in the relational model with integrity constraints. Henceforth, we indicate with AG the alphabet of the relation symbols of G and with CG the set of integrity constraints specified on AG . – S is the source schema, constituted by the schemata of the various sources ...
transaction - Pearson Education
... transactions that run concurrently and generate results that are consistent with the results that would have occurred if they had run separately. • Two-phased locking is one of the techniques used to achieve serializability. ...
... transactions that run concurrently and generate results that are consistent with the results that would have occurred if they had run separately. • Two-phased locking is one of the techniques used to achieve serializability. ...