Distributed Databases
... If Q is replicated at n sites, then a lock request message must be sent to more than half of the n sites in which Q is stored. The transaction does not operate on Q until it has obtained a lock on a majority of the replicas of Q. When writing the data item, transaction performs writes on all ...
... If Q is replicated at n sites, then a lock request message must be sent to more than half of the n sites in which Q is stored. The transaction does not operate on Q until it has obtained a lock on a majority of the replicas of Q. When writing the data item, transaction performs writes on all ...
Database Recovery
... After the completion of the static backup, still backup log file, when a disk failure occurred, we can load the backup of the data and use the copy of log to redo the completed transaction We can restore the database to the correct state before failure at a certain time, but we do not need to re ...
... After the completion of the static backup, still backup log file, when a disk failure occurred, we can load the backup of the data and use the copy of log to redo the completed transaction We can restore the database to the correct state before failure at a certain time, but we do not need to re ...
vdb_formatted2 - USF Computer Science
... The pages are automatically registered with a server (currently, a WebLogic [3] server), so the designer can “run” the pages and immediately see the results of his work in a browser. Figure 3 illustrates the WebSheets code generation process. From the designer’s WYSIWYG specifications, WebSheets gen ...
... The pages are automatically registered with a server (currently, a WebLogic [3] server), so the designer can “run” the pages and immediately see the results of his work in a browser. Figure 3 illustrates the WebSheets code generation process. From the designer’s WYSIWYG specifications, WebSheets gen ...
database system
... Create databases Create tables Create supporting structures Read database data Modify database data (insert, update, delete) Maintain database structures Enforce rules Control concurrency Provide security Perform backup and recovery ...
... Create databases Create tables Create supporting structures Read database data Modify database data (insert, update, delete) Maintain database structures Enforce rules Control concurrency Provide security Perform backup and recovery ...
Estimating the Compression Fraction of an Index Using Sampling
... Null Suppression (NS): This technique is used to suppress either zeros or blanks in each tuple. The key idea is to represent a sequence of zeros and blanks by a special character, followed by a number that indicates the length of the sequence. For example, consider a single column index whose data t ...
... Null Suppression (NS): This technique is used to suppress either zeros or blanks in each tuple. The key idea is to represent a sequence of zeros and blanks by a special character, followed by a number that indicates the length of the sequence. For example, consider a single column index whose data t ...
Fed
... a page corresponds to the display of a section/categorie/bud. all buds of the displayed category are clickable all categories of the displayed section are clickable all sections are always available. a page is displayed by a centralized .php program FedHTMLDocument.php (still called GenoretHTMLDocum ...
... a page corresponds to the display of a section/categorie/bud. all buds of the displayed category are clickable all categories of the displayed section are clickable all sections are always available. a page is displayed by a centralized .php program FedHTMLDocument.php (still called GenoretHTMLDocum ...
Performance evaluation of parallel transaction processing in shared
... PE that have participated during execution of the respective transaction. We support the optimization proposed in [ML086] where read-only sub-transactions only participate in the first commit phase. CPU requests are served by a single CPU per PE. The average number of instructions per request can be ...
... PE that have participated during execution of the respective transaction. We support the optimization proposed in [ML086] where read-only sub-transactions only participate in the first commit phase. CPU requests are served by a single CPU per PE. The average number of instructions per request can be ...
Top Ten Benchmarking Misconceptions
... each different database platform, then by all means yes. Otherwise, you simply can not compare the databases reliably by simply installing and running the same test for each. There are far too many dependencies and variables to trust such a simplistic approach. 9. Transactions per Second (i.e. TPS) ...
... each different database platform, then by all means yes. Otherwise, you simply can not compare the databases reliably by simply installing and running the same test for each. There are far too many dependencies and variables to trust such a simplistic approach. 9. Transactions per Second (i.e. TPS) ...
mySQL Introduction
... The goal of using foreign keys is that tables can be related without repeating data Note that foreign keys in SQL are used to c heck and enforce referential integrity, not to join tables. If you want to get results from multiple tables from a SELECT stat ement, you do this by performing a join b etw ...
... The goal of using foreign keys is that tables can be related without repeating data Note that foreign keys in SQL are used to c heck and enforce referential integrity, not to join tables. If you want to get results from multiple tables from a SELECT stat ement, you do this by performing a join b etw ...
CS chit-chat - ERI people pages
... Query translation • Gazetteer is an instance of a much more general problem • To wit: – how to describe the automatic translation of dynamic queries written in an abstract query language to SQL – in an easy, powerful, flexible way – making as few assumptions as possible about the underlying schema ...
... Query translation • Gazetteer is an instance of a much more general problem • To wit: – how to describe the automatic translation of dynamic queries written in an abstract query language to SQL – in an easy, powerful, flexible way – making as few assumptions as possible about the underlying schema ...
Database Programming (using ADO)
... LAN can use these components to easily integrate information from a variety of sources, both relational (SQL) and non-relational ...
... LAN can use these components to easily integrate information from a variety of sources, both relational (SQL) and non-relational ...
Relational Database Management Systems, Database Design
... key in the same or another table • A FK must match an existing primary key value (or else be null) • If a FK is part of a primary key, that FK cannot be null • In order for a relation to be established between two tables, they both must contain a common data element • (e.g. a field that has been def ...
... key in the same or another table • A FK must match an existing primary key value (or else be null) • If a FK is part of a primary key, that FK cannot be null • In order for a relation to be established between two tables, they both must contain a common data element • (e.g. a field that has been def ...
SQL
... For example, in SQL 2000, when a new column was created, the column name and data type could be found in an internal System Table called syscolumns. All SQL objects produce metadata. ...
... For example, in SQL 2000, when a new column was created, the column name and data type could be found in an internal System Table called syscolumns. All SQL objects produce metadata. ...
CHAPTER 3 Relational Database Management System: Oracle™
... is a recursive query in which the data tree needs to be traversed from the employee node all the way down to the leaves in the sub-tree. One common strategy to solve this problem is to use a temporary table of social security numbers. Initially, this temporary table will store the next level supervi ...
... is a recursive query in which the data tree needs to be traversed from the employee node all the way down to the leaves in the sub-tree. One common strategy to solve this problem is to use a temporary table of social security numbers. Initially, this temporary table will store the next level supervi ...
Chapter 8
... in the query but not those needed in nested queries The WHERE-clause specifies the conditions for selection and join of tuples from the relations specified in the FROMclause GROUP BY specifies grouping attributes HAVING specifies a condition for selection of groups ORDER BY specifies an order for di ...
... in the query but not those needed in nested queries The WHERE-clause specifies the conditions for selection and join of tuples from the relations specified in the FROMclause GROUP BY specifies grouping attributes HAVING specifies a condition for selection of groups ORDER BY specifies an order for di ...
data warehouse - Computer Science, Stony Brook University
... 2. An OLAP query reads HUGE amount of data and generates the required result. The query is very complex too. Thus special primitives have to provided to support this kind of data access. 3. OLAP systems access historical data and not current volatile data while OLTP systems access current up-to-date ...
... 2. An OLAP query reads HUGE amount of data and generates the required result. The query is very complex too. Thus special primitives have to provided to support this kind of data access. 3. OLAP systems access historical data and not current volatile data while OLTP systems access current up-to-date ...
Transactions
... each pair of transactions Ti and Tj such that Tj reads a data item previously written by Ti, the commit operation of Ti appears before the read operation of Tj. Every cascadeless schedule is also recoverable ...
... each pair of transactions Ti and Tj such that Tj reads a data item previously written by Ti, the commit operation of Ti appears before the read operation of Tj. Every cascadeless schedule is also recoverable ...
chapter07
... database data into RAM for Elena Elena changes data in RAM DBMS updates database with Elena’s change Concepts of Database Management, 5th Edition ...
... database data into RAM for Elena Elena changes data in RAM DBMS updates database with Elena’s change Concepts of Database Management, 5th Edition ...
SAS® and Relational Databases: What You Should Know Before You Code
... This is possibly one of the most expensive queries you could run. Hash joins do not use indexes and thus must read the entire table, commonly know as a full table scan It will build a hash structure for the second input before reading each row from the first input one at a time. If you find people n ...
... This is possibly one of the most expensive queries you could run. Hash joins do not use indexes and thus must read the entire table, commonly know as a full table scan It will build a hash structure for the second input before reading each row from the first input one at a time. If you find people n ...
