Lecture 6: Query optimization, query tuning
... important for the choices made when planning query execution. • Time for operations grow (at least) linearly with size of (largest) argument. (Note that we do not have indexes for intermediate results.) • The total size can even be used as a crude estimate on the running time. ...
... important for the choices made when planning query execution. • Time for operations grow (at least) linearly with size of (largest) argument. (Note that we do not have indexes for intermediate results.) • The total size can even be used as a crude estimate on the running time. ...
Strong Types for Relational Databases
... database. It tells us, for example, how many columns each table must have and what the types of the values in each column should be. Furthermore, some columns may be singled out as keys, some may be allowed to take null values. Constraints can be declared for specific columns, and foreign key constr ...
... database. It tells us, for example, how many columns each table must have and what the types of the values in each column should be. Furthermore, some columns may be singled out as keys, some may be allowed to take null values. Constraints can be declared for specific columns, and foreign key constr ...
Performance Tradeoffs in Read-Optimized Databases
... spend about 5-10 msec while the heads perform a seek to the new data location. To preserve high performance, the system needs to minimize the time spent on seeks. For multiple concurrent sequential requests, this is typically achieved by prefetching a large amount of data from one file before seekin ...
... spend about 5-10 msec while the heads perform a seek to the new data location. To preserve high performance, the system needs to minimize the time spent on seeks. For multiple concurrent sequential requests, this is typically achieved by prefetching a large amount of data from one file before seekin ...
Functionalitis of the database
... each patient‘s data who at least completes a core dataset as predetermined by the “Red Fields” of the ESID Online Database (provided the Documenting Centre has complied with all applicable data protection regulations) by June 30 th of each year. The accumulated compensation is due on September, 15 o ...
... each patient‘s data who at least completes a core dataset as predetermined by the “Red Fields” of the ESID Online Database (provided the Documenting Centre has complied with all applicable data protection regulations) by June 30 th of each year. The accumulated compensation is due on September, 15 o ...
Chapter 17 - Spatial Database Group
... Multiple optimization objectives The weighting of communication costs versus local processing costs depends on network characteristics. There are many more possible access plans for a distributed query. ...
... Multiple optimization objectives The weighting of communication costs versus local processing costs depends on network characteristics. There are many more possible access plans for a distributed query. ...
Principles of Good Database Design
... parts, hiring/firing employees, finding new suppliers, or making changes to the production process. Let us focus on a production process DSS application. The manager may be deciding where to place a new piece of equipment or how to add a new product part to the production sequence. With the use of s ...
... parts, hiring/firing employees, finding new suppliers, or making changes to the production process. Let us focus on a production process DSS application. The manager may be deciding where to place a new piece of equipment or how to add a new product part to the production sequence. With the use of s ...
Distributed Database Systems
... - more clients can be supported - object clustering improves performance considerably • disadvantages/problems: - method execution only on clients - object-level locking - object clustering - large client buffer pool required ...
... - more clients can be supported - object clustering improves performance considerably • disadvantages/problems: - method execution only on clients - object-level locking - object clustering - large client buffer pool required ...
PPT - Oracle
... Copyright © 2014 Oracle and/or its affiliates. All rights reserved. | Berkeley DB ...
... Copyright © 2014 Oracle and/or its affiliates. All rights reserved. | Berkeley DB ...
Parallel Databases
... ORDER partitioned on ORDERKEY, CUSTOMER partitioned on CUSTKEY Retrieve rows from ORDER, then use ORDER.CUSTKEY to direct appropriate rows to nodes with CUSTOMER ...
... ORDER partitioned on ORDERKEY, CUSTOMER partitioned on CUSTKEY Retrieve rows from ORDER, then use ORDER.CUSTKEY to direct appropriate rows to nodes with CUSTOMER ...
INT7016 – Contemporary Issues in Database Development
... checkpoint (CKPT) process has been started, in which case it will perform this task. • The parameter LOG_CHECKPOINT_TIMEOUT is used to determine the interval of time between checkpoints. • The parameter LOG_CHECKPOINT_INTERVAL is used to determine how many redo file blocks must be filled since the p ...
... checkpoint (CKPT) process has been started, in which case it will perform this task. • The parameter LOG_CHECKPOINT_TIMEOUT is used to determine the interval of time between checkpoints. • The parameter LOG_CHECKPOINT_INTERVAL is used to determine how many redo file blocks must be filled since the p ...
Relational Databases
... DBMS, schemas, the data dictionary, and DBMS languages. • Describe what a relational database is and how it organizes data. • Create a set of well-structured tables to properly store data in a relational database. Copyright © 2015 Pearson Education, Inc. ...
... DBMS, schemas, the data dictionary, and DBMS languages. • Describe what a relational database is and how it organizes data. • Create a set of well-structured tables to properly store data in a relational database. Copyright © 2015 Pearson Education, Inc. ...
The Relational Model - Simon Fraser University
... E.g., sid is a key for Students. (What about name?) The set {sid, gpa} is a superkey. For each key attribute values need to be provided, i.e. a key cannot have the special value null. ...
... E.g., sid is a key for Students. (What about name?) The set {sid, gpa} is a superkey. For each key attribute values need to be provided, i.e. a key cannot have the special value null. ...
Database Systems: Design, Implementation, and Management
... “Raw” facts that have little meaning unless they have been organized in some logical manner. The smallest piece of data that can be “recognized” by the computer is a single character. Example: the letter A, the number 5, symbols: ‘ ? > * +. ...
... “Raw” facts that have little meaning unless they have been organized in some logical manner. The smallest piece of data that can be “recognized” by the computer is a single character. Example: the letter A, the number 5, symbols: ‘ ? > * +. ...
CS 361-001 Database Systems, Dr. Wing Huen
... (g) decompose proposed relational schemas that are not in 3NF or BCNF into 3NF or BCNF 4. [Basic file organization and various file structure methods] (a) determine the access time of records based on the file organization and file structure (b) specify the type of stable and non-stable storage in t ...
... (g) decompose proposed relational schemas that are not in 3NF or BCNF into 3NF or BCNF 4. [Basic file organization and various file structure methods] (a) determine the access time of records based on the file organization and file structure (b) specify the type of stable and non-stable storage in t ...
The Hobgoblin of Little Minds
... In the serializable isolation level, transactions must execute in such a way that they appear to be executed one at a time (“serially”), rather than concurrently. […] In other words, concurrent transactions executing in serializable mode are only permitted to make database changes they could have ma ...
... In the serializable isolation level, transactions must execute in such a way that they appear to be executed one at a time (“serially”), rather than concurrently. […] In other words, concurrent transactions executing in serializable mode are only permitted to make database changes they could have ma ...
Database - bYTEBoss
... – The database is then in the same consistent state as it was at the point when the transaction log was backed up for the very last time – When you recover a database using a Full Database Backup, SQL Server 2005 first reconstructs all database files in the correct locations and then the system reco ...
... – The database is then in the same consistent state as it was at the point when the transaction log was backed up for the very last time – When you recover a database using a Full Database Backup, SQL Server 2005 first reconstructs all database files in the correct locations and then the system reco ...
Romancing Your Data: The Getting-to-Know-You Phase
... Statistical Modelers and Business Analysts are the typical users of the data, and the term ‘analyst’ will be used here broadly for ‘anyone who uses an Oracle database to solve business problems.’ An analyst’s main interest in the database is to solve business problems that have data-driven solutions ...
... Statistical Modelers and Business Analysts are the typical users of the data, and the term ‘analyst’ will be used here broadly for ‘anyone who uses an Oracle database to solve business problems.’ An analyst’s main interest in the database is to solve business problems that have data-driven solutions ...
Here
... • It cannot have a NULL value, or • What is the default, if the value is not specified (say in an insertion) ...
... • It cannot have a NULL value, or • What is the default, if the value is not specified (say in an insertion) ...
Computer Forensics
... data access at the row or column level; implemented using VIEW database object • VPDs are also referred to as row-level security (RLS) or fine-grained access (FGA) • SQL Server does not support VPDs • Microsoft SQL Server 2000 system function of ...
... data access at the row or column level; implemented using VIEW database object • VPDs are also referred to as row-level security (RLS) or fine-grained access (FGA) • SQL Server does not support VPDs • Microsoft SQL Server 2000 system function of ...
Romancing Your Data: The Getting-to-Know-You Phase
... the database ‘metadata’. Just to be clear, the definition of ‘metadata’ is ‘data about data.’ To illuminate the ‘data about data’ concept, consider what happens when you take a picture on a digital camera. The image is stored in a compression format such as a JPEG (Joint Photographic Experts Group). ...
... the database ‘metadata’. Just to be clear, the definition of ‘metadata’ is ‘data about data.’ To illuminate the ‘data about data’ concept, consider what happens when you take a picture on a digital camera. The image is stored in a compression format such as a JPEG (Joint Photographic Experts Group). ...
w01_1_INF280_Basic_Concepts_Concurrency_Control
... • Database designers responsibility is to communicate with all prospective database users in order to understand their requirements and to create a design that meets these requirements. ...
... • Database designers responsibility is to communicate with all prospective database users in order to understand their requirements and to create a design that meets these requirements. ...
Setup of database, JMS broker, and FTP server
... uses FTP as transport protocol requires the installation of one or more FTP servers, normally one per location Remotefile plugin needed: ...
... uses FTP as transport protocol requires the installation of one or more FTP servers, normally one per location Remotefile plugin needed: ...
Database Systems, Ch 17
... – If the system crashes, we can recover to a consistent database state by examining the log. – The log contains a record of every write that modifies some DB item => it is possible to undo the the write operations of transaction T. How? By tracing backward through the log and resetting all items cha ...
... – If the system crashes, we can recover to a consistent database state by examining the log. – The log contains a record of every write that modifies some DB item => it is possible to undo the the write operations of transaction T. How? By tracing backward through the log and resetting all items cha ...
upgrading existing databases recommendations for irrigation districts
... Who will update the client software? Each district has a slightly different client (the program that handles the water ordering and reporting). Client software compatibility is the only significant problem when moving to a new database, as the only database that is compatible with current client is ...
... Who will update the client software? Each district has a slightly different client (the program that handles the water ordering and reporting). Client software compatibility is the only significant problem when moving to a new database, as the only database that is compatible with current client is ...
