presentation source
... • system checks data upon creation and data addition • rejects duplicates and returns an error • should only be created on a column that requires uniqueness eg. ssn, acct code • can be created as a composite or single column • helps in maintaining data integrity • boosts search performance ...
... • system checks data upon creation and data addition • rejects duplicates and returns an error • should only be created on a column that requires uniqueness eg. ssn, acct code • can be created as a composite or single column • helps in maintaining data integrity • boosts search performance ...
Performance Optimization
... The optimizer first joins the small tables together and then joins that result with the large table (also called as Product/Merge Join). To work well, the join fields of the small table must comprise an index of the large table. The join fields do not have to be indexes in the small table. Col ...
... The optimizer first joins the small tables together and then joins that result with the large table (also called as Product/Merge Join). To work well, the join fields of the small table must comprise an index of the large table. The join fields do not have to be indexes in the small table. Col ...
week5
... •should only be created for a column that is most often retrieved in order •greatly increases performance when searching for contiguous key values… especially a range •slows down data updates due to the sorting ...
... •should only be created for a column that is most often retrieved in order •greatly increases performance when searching for contiguous key values… especially a range •slows down data updates due to the sorting ...
ppt slides
... in the database that, if joined, might contain rows having all keywords. The resulting relation will contain all potential rows having all keywords specified in the query. If we view the schema graph G as an undirected graph, this step enumerates join trees, i.e., subtrees of G such that: (a) the le ...
... in the database that, if joined, might contain rows having all keywords. The resulting relation will contain all potential rows having all keywords specified in the query. If we view the schema graph G as an undirected graph, this step enumerates join trees, i.e., subtrees of G such that: (a) the le ...
About AutoLookup queries that automatically fill in data (MDB)
... table Design view (Design view: A window that shows the design of these database objects: tables, queries, forms, reports, macros, and data access pages. In Design view, you can create new database objects and modify the design of existing ones.) is set to Yes (No Duplicates). The join field you add ...
... table Design view (Design view: A window that shows the design of these database objects: tables, queries, forms, reports, macros, and data access pages. In Design view, you can create new database objects and modify the design of existing ones.) is set to Yes (No Duplicates). The join field you add ...
SQL 1. What are the types of SQL statement? Data Manipulation
... delete = delete- so it can be rolled back Delete - delete deletes the records from table it can be rollbacked also you can give the where condiition to it. Truncate - delete all records from table There is no rollback it always commit without givening the commit Truncate: Drop all object's statistic ...
... delete = delete- so it can be rolled back Delete - delete deletes the records from table it can be rollbacked also you can give the where condiition to it. Truncate - delete all records from table There is no rollback it always commit without givening the commit Truncate: Drop all object's statistic ...
MS SQL Server
... I want to print the employee name and machine name. If I write a query using inner join, then the second employee will not be displayed as the mid in his record is not avilable with the second table. So I go for left outer join. The query is as shown below: Select Ename, ManufacturerName from Employ ...
... I want to print the employee name and machine name. If I write a query using inner join, then the second employee will not be displayed as the mid in his record is not avilable with the second table. So I go for left outer join. The query is as shown below: Select Ename, ManufacturerName from Employ ...
Lab 13-final
... % operator is used inside the like operator. Ex. ‘%United’- Returns strings which ends with with United ‘United%’ - Returns string which starts with United ‘%United%’- Returns string which contains United irrespective of the location. ...
... % operator is used inside the like operator. Ex. ‘%United’- Returns strings which ends with with United ‘United%’ - Returns string which starts with United ‘%United%’- Returns string which contains United irrespective of the location. ...
DBXplorer: A system for keyword based search over relational
... FK-Comp: If column c1 is a subset of values in another column c2, we retain only values in c1 CP-Comp: It is used when pairs of columns share common keywords but are not tied by FK ...
... FK-Comp: If column c1 is a subset of values in another column c2, we retain only values in c1 CP-Comp: It is used when pairs of columns share common keywords but are not tied by FK ...
Database Interview Questions - Nutrition Foundation of India
... A table can have only one PRIMARY KEY whereas there can be any number of UNIQUE keys. The columns that compose PK are automatically define NOT NULL, whereas a column that compose a UNIQUE is not automatically defined to be mandatory must also specify the column is NOT NULL. Q: What is ON DELETE CASC ...
... A table can have only one PRIMARY KEY whereas there can be any number of UNIQUE keys. The columns that compose PK are automatically define NOT NULL, whereas a column that compose a UNIQUE is not automatically defined to be mandatory must also specify the column is NOT NULL. Q: What is ON DELETE CASC ...
Relationships - SQL Server 2008 Tutorial
... relationships between related tables are valid You cannot enter a value in the foreign key column of the child table (Orders) if that value does not exist in the primary key of the parent table (Customers) You cannot delete a row from a primary table (Customers) if rows matching it exist in a re ...
... relationships between related tables are valid You cannot enter a value in the foreign key column of the child table (Orders) if that value does not exist in the primary key of the parent table (Customers) You cannot delete a row from a primary table (Customers) if rows matching it exist in a re ...
Link to Slides
... • Most databases require that if a column is declared to have a type, each element in that column must conform or be converted. ...
... • Most databases require that if a column is declared to have a type, each element in that column must conform or be converted. ...
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 ...
SQL
... Count all records: COUNT (*) AS colForAnswers Count all records in a column: COUNT (column) AS colForAnswers Count distinct values: COUNT(DISTINCT columnName) AS colForAnswers SELECT crimeType, COUNT(DISTINCT Address) AS HousesAffected FROM crimes ...
... Count all records: COUNT (*) AS colForAnswers Count all records in a column: COUNT (column) AS colForAnswers Count distinct values: COUNT(DISTINCT columnName) AS colForAnswers SELECT crimeType, COUNT(DISTINCT Address) AS HousesAffected FROM crimes ...
SQL
... Count all records: COUNT (*) AS colForAnswers Count all records in a column: COUNT (column) AS colForAnswers Count distinct values: COUNT(DISTINCT columnName) AS colForAnswers SELECT crimeType, COUNT(DISTINCT Address) AS HousesAffected FROM crimes ...
... Count all records: COUNT (*) AS colForAnswers Count all records in a column: COUNT (column) AS colForAnswers Count distinct values: COUNT(DISTINCT columnName) AS colForAnswers SELECT crimeType, COUNT(DISTINCT Address) AS HousesAffected FROM crimes ...
Access
... Need a repeating report Many people using same data at once complex query track sub-information – (such as items on an order; hours worked by employees) ...
... Need a repeating report Many people using same data at once complex query track sub-information – (such as items on an order; hours worked by employees) ...
Access1
... Need a repeating report Many people using same data at once complex query track sub-information – (such as items on an order; hours worked by employees) ...
... Need a repeating report Many people using same data at once complex query track sub-information – (such as items on an order; hours worked by employees) ...
SQL
... • accepts sql commands using their version of the standard query language • Allows access to the data inside the SQL server • Organized into databases • Tables (like spreadsheets) inside databases • Gui management interface – Access / mysql workbench / mssql studio mgr ...
... • accepts sql commands using their version of the standard query language • Allows access to the data inside the SQL server • Organized into databases • Tables (like spreadsheets) inside databases • Gui management interface – Access / mysql workbench / mssql studio mgr ...
udf - Personify
... table and any records from the left table that match – Usually best to rewrite as a LOJ ...
... table and any records from the left table that match – Usually best to rewrite as a LOJ ...
Mobule 7 - Enhanced SQL
... module looks at additional SQL commands that let you look at searching more than one table for to get the information you need. You are actually comparing the table data in your JOIN statements (there are several different types) and other similar statements. A JOIN statement is a relational operati ...
... module looks at additional SQL commands that let you look at searching more than one table for to get the information you need. You are actually comparing the table data in your JOIN statements (there are several different types) and other similar statements. A JOIN statement is a relational operati ...
Link - Faculty
... • Data Warehousing applications make more read operation. • Row oriented have an overhead of seeking through all columns. • Can be slower for some applications like OLTP with many row inserts. ...
... • Data Warehousing applications make more read operation. • Row oriented have an overhead of seeking through all columns. • Can be slower for some applications like OLTP with many row inserts. ...