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Question | Answer |
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What is the UNIQUE constraint? | Specifically identifies which column should not contain duplicate values. |
What is the CHECK constraint? | Allows the admin to limit the types of data a user can insert into that column of the database. |
What is a default constraint? | Used to insert a default value into a column. |
What is the primary key? | This uniquely identifies a column in the db. Has to have a unique constraint by default. Cannot be Null and data type must match. Ensures entity integrity(Uniquely id each row). Not always created as CLUSTERED indexes if one is already made. |
What is a foreign key? | This is a column in one table that points to the primary key in another table(defines relationship between two tables). Ensures domain and referential integrity, not entity integrity. There is not a predefined limit for foreign keys. |
Why is it a bad idea to let a foreign key contain a NULL value? | Because it may be impossible to verify the constraints if a foreign key consists of two or more columns if one of them is NULL. |
What is a self-reference? | When the foreign key refers to columns in the same table. |
What is XQuery? | A query and functional programming language designed to query collections of XML data. |
What is SQLCMD? | A command line application that comes with SQL and exposes the management features of SQL Server. It allows SQL queries to be written and executed from the command prompt. |
What is TRANSACT-SQL | This is the primary means of programming and manageing SQL Server. When you use an SSMS to perform an action, it is using T-SQL commands in the background to do the work. |
What are the three types of files in SQL? | MDF = Primary data files, NDF = Secondary data files and LDF = Log files |
Database objects are divided into two categories: | Storage and Programmability |
Tables created using the ________ statement are used to store data. | CREATE TABLE |
Constraints are also referred to as ____ constraints. | Column; limitations or rules placed on a field or column to ensure that data that is considered invalid is not entered. |
In order to use views, you must use the ______ T-SQL statement to show data from the tables. | SELECT |
DDL influences _____, while _______ influences actual data stored in tables. | Database objects, DML |
The MS database server that hosts relational databases is called _____ | MS SQL Server |
The code DML statements are (5) | MIDUS: MERGE, INSERT, DELETE, UPDATE, SELECT |
System views belong to the ______ | sys schema |
What are 6 constraint types? | Unique, Check(domain Integrity), Default(domain integrity), Not Null, Primary Key(entity integrity), Foreign Key(referential integrity) |
A bit is the T-SQL integer data type that can take a ___ of 1, 0 or NULL. | value |
A regular character uses ___ bytes of storage, whereas a unicode character requires ____ bytes. | one, two |
When querying a database you can obtain faster results from properly ______ tables and views. | indexed |
What prefix must you have in front of a string to use Unicode? | N |
What is the default length for the CAST function? | 30 |
What is native auditing? | The process of extracting trails on a regular basis so they can be transferred to a designated security system where the database admins do not have access, this ensures a certain level of separation of duties and provides evidence that the audit trails w |
What is a two-phase commit system? | A feature of a transaction processing system which enables DB's to be returned to the pre-transaction state if some error condition occurs. All databases are updated or none of them are. |
Name 4 types of decomposition | Top-down, Bottom-up, Inside-out, Mixed |
What is the inside-out approach to db design? | A type of bottom-up approach, the inside-out method begins with identifying a few important concepts then proceeds outward radially. |
What is the top-down approach? | When a schema is created through a series of successive refinements, starting with the first schema. |
What is the With Execute Owner clause? | When creating a stored procedure, this can be used to allow the person running the SP to have the same permissions as the person who owns the SP. This is better than granting SELECT to the user. |
What is abstraction? | A method of coding that enables a user to focus on the coding rather than the syntax for a specific database API, allowing them to use generic methods of access as long as they have the additional codes or libraries which fill in the blanks. |
What is the correct way to select an avg of a column? | SELECT AVG("column name") FROM "table name" |
What is a clustered index? | Large amount of selects on a table, create a clustered index on the primary key of the table. This index should be the most common column that is in your WHERE clauses for queries against this table. So if most of the time you search by primary key, then |
What is a non-clustered index? | Non-clustered indexes are not copies of the table but a sorting of the columns you specify that "point" back to the data pages in the clustered index. Add non-clustered indexes for queries that return smaller result sets. (Optimal Performance) |
What are 3 characteristics of a simple view? | 1. It does not have any usage of SQL group functions or grouping of data. |
2. DML operations are allowed on the view | |
3. It fetches data from one database table only | |
Which DB design process allows you to create a data model independent of a specific DBMS? | Logical DB design |
What's the difference between an INNER join and an OUTER join? | INNER will only produce matching rows from both tables while OUTER will join all rows from both tables whether they match or not. |
What command do you use to invoke a stored procedure? | Execute |
If you have already defined a view on a specific table, then you add columns to that table, what must you do to the view? | Use the CREATE or REPLACE VIEW command to redefine it. |
What are three things true about views? | 1. If a view definition contains the DISTINCT keyword, rows cannot be deleted through the view. |
2. The WITH OBJECT IDENTIFIER clause is used to specify a top level (root) object view. | |
3. The OR REPLACE option is used to change the definition of a existing view without dropping and recreating. | |
What is DB prototyping? | Building a working model of the DB system in order to suggest improvements or add new features. |
When is the best time to back up dynamic log files? | When the server is stopped. |
Define Normal Form | 1NF - Eliminate duplicative columns from the same table. |
-Create separate tables for each group of related data and identify each row with a unique column (the primary key). | |
2NF - Move repeating fields into a new table that contains a primary key, and relate it back to the old table using a foreign key. (requirement that each field value in a table is associated with only one row) | |
3NF - Eliminate columns not- transitively dependent (useless) on key | |
4NF - all in table are dependent on superkey | |
5NF - every join is implied by superkeys of the table | |
How do you adjust indexes to reduce fragmentation from page splits? | Set the fillfactor to 60. |
What is a fillfactor? | It specifies a percentage that indicates how much free space will be in the leaf level of each index page. |
How would you set fillfactor? | ALTER INDEX ALL ON dbo.OrderDetails REBUILD WITH (FILLFACTOR = 60); |
What would happen if you had a BETWEEN operator of BETWEEN 'D' and 'F' | You would get all values for D, E but not F. (MUST HAVE AND IN BETWEEN STATEMENT) |
What is the bottom up approach? | Breaking down the smaller components so that each describes a basic fragment. |
Which form of database design uses secondary storage media? | Physical database design |
Mark works as a Database Designer for Reon Inc. He is assigned the task to create a database for the company. He issues the following query to create the database. | |
CREATE DATABASE '24342' | |
What will be the output of the query? | A database will be created. |
When do you pick the DBMS? | Prior to the Logical design phase. |
Which of the following statements are true regarding the procedural data manipulation language? | It requires users to specify which data is needed and how to obtain it, it is a low-level DML, it requires users to know the data structure used in the db. |
What does the IDENTITY constraint do? | It's used on the primary key to automatically start with 1 and auto-increment by 1. |
Database objects are divide into two categories: | Storage and Programmability |
What always returns a value but never updates data? | A function |
The core DDL statements are: | CREATE, DROP, ALTER |
The foreign key constraint is a ____ identifier. | Relationship; Enforces referential integrity |
Name 3 things which can be used to improve query performance | A primary key, a UNIQUE index and a CLUSTERED index |
T/F: A single INSERT statement can be used to add rows to multiple tables. | False |
Can you change the IDENTITY constraint of an existing column with an ALTER statement? | No |
T/F: Null is a valid constraint | False, NULL is not a constraint |
Which 4 things always have a related data type? | Column, localvariable, expression and parameter. |
SQL server supports ____ conversions without using actual callout functions CAST or CONVERT | Implicit,(automatic) |
A regular character uses how much storage? | 1 byte, 256 possible characters. |
A unicode characters uses how much storage? | 2 bytes, This allows 65,536 characters at almost any language. |
For the CHAR data set, it is a _____ length and uses ___ bytes: | Fixed, N |
What is one thing to consider when creating a view? | Database performance |
An ___ ____ is the same thing as a CROSS JOIN with a WHERE condition: | INNER JOIN |
What's the most efficient way to delete all rows from a table? | TRUNCATE command; does not log each row |
How do you start a transaction? | Use BEGIN TRAN |
A ____ will combine the results of two or more queries into a resulting set that includes all the rows belonging to the query: | UNION; without any duplicates. Duplicates require UNION ALL. |
If you are querying the same table for two different things you'd use a.... | UNION |
A clustered index usually _____ performance when inserting data. | worsens, because it's constantly sorting it. Improves it for retrieving it though. Physical sort. Only 1 per table. |
What 2 things speeds up data retrieval? | Primary key constraints and Clustered indexes |
What 3 reasons should you consider using a clustered index? | 1. Columns contain a large number of distinct values |
2. Columns are accessed sequentially | |
3. Queries return large result sets | |
Which normal form ensures that each attribute describes the entity? | 2nf |
What command allows a Windows account to access SQL-Server? | CREATE LOGIN |
Any ___ permission will always override a GRANT permission. | DENY |
A ____ backup contains only the data that has changed since the last FULL backup. | Differential |
All users are automatically members of the ______ database role. | Public |
Use the _____ command to recover data that was accidentally deleted by a user. | Restore |
Name 3 levels of security supported by SQL Server | Server, Database and Table |
The sa account is only used in | mixed-mode |
The ___ role gives access to anything on the SQL server, while the ____ role gives full access to a specific database: | sysadmin, db_owner |
What language are triggers written in? | DML or DDL |
What happens if data is missing for a particular column when designing the INSERT SQL statement? | The INSERT statement uses the default value for the column. |
Name the two types of prototyping | Requirements and Evolutionary |
What steps should you take to create full-text searching? | 1. Create a full text catalog in the database |
2. Create a full text index on the column in question | |
What command would you use to track changes to a table? | ALTER TABLE tablename |
ENABLE CHANGE_TRACKING | |
Application design involves 2 important activities: | transaction design and interface design |
What does degree refer to? | The number of columns. |
index | (table scoped object and not securable) is a data structure that improves the speed of data retrieval operations on a database table. The disadvantage of indexes is that they need to be created and updated,. |
Flat-type databases | is simplistic in design. They are two dimensional tables that are consisting to rows and columns. for fast searches. |
hierarchical database | is similar to a tree structure (such as a family tree). Each parent table can have multiple children, but each child table can have only one parent. |
relational database | A relational database is similar to a hierarchical database in that data is stored in tables and any new information is automatically added to the table without the need to reorganize the table itself. Minimizes the amount of redundant data stored in the |
SELECT | Retrieves rows from the database and enables the selection of one or many rows or columns from one or many tables in SQL Server. |
INSERT | Adds one or more new rows to a table or a view in SQL Server. Must contain a table or view name into which to insert the data. Can be used to insert explicit values into a table or to insert the result set returned by a query into a table. |
UPDATE | Changes existing data in one or more rows in a table or view(changes the data in the table) |
DELETE | Removes rows from a table or view(, which deletes data from within a table) Use for smaller databases |
MERGE | Performs insert, update, or delete operations on a target table based on the results of a join with a source table. |
USE | Changes the database context |
CREATE | Creates a SQL Server database object (table, view, or stored procedure) |
ALTER | Changes an existing object(changes the object definition) |
DROP | A DDL statement used to remove objects, such as tables, views, stored procedures, and triggers , from a database. |
Collation | refers to a set of rules that determine how data is sorted and compared. By default, SQL Server has predefined collation precedence. If you wish to override how data is being sorted, you must use a collation clause. |
Transact-SQL data types | bit, decimal and numeric. Transact-SQL data types that have a fixed precision and scale. money and smallmoney are Transact-SQL data types you would use to represent monetary or currency values. |
view | is simply a virtual table consisting of different columns from one or more tables. Unlike a table, a view is stored in a database as a query object; therefore, a view is an object that obtains its data from one or more tables. View is a database object th |
Views ensure the security of data by restricting access to the following data | • Specific rows of tables |
• Specific columns of tables | |
• Specific rows and columns of tables | |
• Rows obtained by using joins | |
• Statistical summaries of data in given tables | |
• Subsets of another view or subsets of views and tables | |
Some common examples of views include the following: | • A subset of rows or columns of a base table |
• A union of two or more tables | |
• A join of two or more tables | |
• A statistical summary of base tables | |
• A subset of another view or some combination of views and base tables | |
two major reasons you might want to provide a view instead of enabling users to access the underlying tables in your database: | - Views allow you to limit the type of data users can access. You can grant view permissions in designated tables, and you can also choose to deny permissions for certain information. |
- Views reduce complexity for end users so they don't have to learn how to write complex SQL queries. Instead, you can write those queries on their behalf and hide them in a view. | |
A stored procedure | Can modify the data in permanent tables and return multiple values as output parameters. It doesn't control how underlying data is physically accessed. Can return a value to the caller. |
SQL injection | A code injection technique that exploits security vulnerabilities in the DB layer of an application. |
Precision (p) | is the maximum total number of decimal digits that can be stored in a numeric data type, both to the left and to the right of the decimal point; this value must be at least 1 and at most 38. The default precision number is 18. |
Explicit conversions require you to use | the functions cast or convert specifically. |
three things you need to be sure to identify in your statement to form a proper SELECT query: | • Columns to retrieve |
• Tables to retrieve the columns from | |
• Conditions, if any, that the data must satisfy | |
SET NOCOUNT statement | shows line stating the number of rows "affected". This is off by default. This will suppress the '(1 row affected) |
JOIN statements | , which combine columns from multiple different tables. JOIN statements can be specified in either the FROM or the WHERE clause, but it is recommended that you specify them in the FROM clause. |
Both the EXCEPT and the INTERSECT statements | are designed to return distinct values by comparing the results of two queries. |
EXCEPT clause | gives you the final result set where data exists in the first query and not in the second dataset. |
INTERSECT clause | gives you the final result set where values in both of the queries match by the query on both the left and right sides of the operand. |
• The number and order of the columns must be the same in all queries. | |
• The data types must be compatible. | |
SELECT statement query | lets you produce individual lists, but the result may be that you get all the information you need but in an individual list format. |
UPDATE statement | The function of the is to change data in a table or view |
UPDATE clause | allows you to modify data stored in tables using data attributes. Note: If you don't specify what records to update, all records or rows will be updated with the new value. To update another table use FROM clause. In this, SET specifies column to be updat |
DELETE syntax | You can identify and delete individual rows from the database |
Normalization | series of steps(or rules) called "forms" the more steps you take, the more normalized your tables. |
Define 5NF | Isolate semantically related multiple relationships |
what happens when you connect two tables | the primary key is replicated from the primary to secondary table, and all the key attributes duplicated from the primary table are known as the foreign key. |
composite primary key | occurs when you define more than one column as your primary key. |
primary drawbacks to using indexes | are the time it takes to build the indexes and the storage space the indexes require. Note: each table can have only one clustered index , data can be sorted in only one way. |
Windows Authentication mode is superior to mixed mode because | users don't need to learn yet another password and because it leverages the security design of the network. |
application role | is a database-specific role intended to allow an application to gain access regardless of the user. |
database index | is a data structure that improves the speed of data retrieval operations on a database table. |
Databases are often put on database servers for what reason | so that they can be accessed by multiple users and provide a higher level of performance. One popular database server is Microsoft SQL Server. |
Exact numeric data types | are the most common SQL Server data types used to store numeric information. |
serveradmin fixed server role | can Configure server -wide settings and issue SHUTDOWN command which immediately stops the SQL server. |
DROP LOGIN | Command will remove a windows user or group from the SQL server. This will not alter Windows its self |
WHERE | is used to obtain only subset of rows that fulfill criterion in the WHERE clause |
REVOKE | removes user access rights or privileges on the database objects granted using the GRANT statement, but does not prevent permissions from being obtained through membership in other roles. |
DENY | Prevents users of members of a role from performing an action on a secure-able object, such as a view, or stored procedure. even if permission is grated directly through membership in another role. |
Dbcreator | Can create, alter,drop, and restore databases |
Diskadmin | Can create, alter, and drop disk files. This is a Fixed server role |
Setupadmin | Can configure linked servers, extend stored procedures and the start-up stored procedure. This is a Fixed server role |
db_denydatareader | Can read from any table in the database, this deny will override an object-level grant |
db_denydatawriter | Blocks modifying data in any table in the database. Will override any object-level grant |
db_ddladmin | can issue DDL commands(statements)(create, alter,drop) |
db_backupoperator | can perform backups, checkpoints, and DBCC commands, but not restores(only sysadmins can perform restores) |
Table sizes | 1MB - 1024 KB - 1 field - 165 bytes. a 100k table - = 16113.28125 kb(15.73563 mb) |
CRUD | In computer programing, create, read, update and delete (CRUD)are the four basic functions of persistent change |
Check constraint | allows you to limit the types of data a user can insert into a the database and that they meet a certain condition. |
Not null constraint | ensures that data is entered in to a cell(cant be blank). |
Trigger | A SQL procedure that initiates an action when an event(INSERT, DELETE or UPDATE) occurs. |
CHARINDEX function | returns the starting position of the specifies expression in a character string. The third parameter of the function is the character position to start searching for the first parameter in the second parameter. If starting ocation is a negative number, se |
Advantage of database over spreadsheet | Database can parse out redundant storage and information obtained from various relational spreadsheets. |
Full Outer Joins | returns all rows from the left table (table1) and from the right table (table2). |
Data Types | huge numbers(way bigger than millions) = bigint |
Big numbers= int(-2,147,483,648 to 2,147,483,647)Can store dates YYYYMMDD(4 bytes) | |
small numbers = smallin(-32768 to 32,767 however req 2 bytes of space) | |
smaller numbers = tinyint(max value of 255 with minimum storage 1 byte) | |
lots of text = varchar(expands as needed) YYYYMMDD(8 bytes) | |
text containing Unicode symbols(diff language or symbols) = nvarchar | |
currency = smallmoney(-214,748.3648 to 214,748.3647 (4 decimal places)) | |
yes/no = bit(value of 0,1 or null) | |
Float = precision and scale(best for finding percent %) | |
decimal(3) - 5 bytes | |
RIGHT OUTER JOIN | preserves the unmatched rows from the second (right) table, joining them with a NULL in the shape of the first (left) table |
Cross Joins | returns a result set that contains all the combinations of rows from two tables that do not have a column in common, also know as a Cartesian product. WHERE conditions should always be included. |
Schema-scoped secure-able | (stored procedure)one that is created within a schema and can receive permissions through that schema. |
Schema | Database s-scoped secure-able. Created within a database and provides a namespace and a security container for database objects. Each secure-able object must have a unique name |
Function | is a database object that can accept values, perform a calculation and return the result to the caller. Can be directly referenced using a SELECT statement. |
referential integrity | Integrity between tables using relationships. |
DEFAULT | Ensures domain integrity by ensuring each record has a column value if one is not assigned. |
Table-valued function | Selects data and returns the results as a table. Cannot modify any permanent tables. |
Scalar function | Returns a single value, based on the input value of a single field(EX: UCASE - Returns the value of the field in all upper case). |
to search strings in a column | The LIKE operator is used together with the % wildcard character |
STR | Returns character data converted from numeric data. The second parameter is for the total length of the output including the decimal point, signs, digits, and spaces. output is round as specified in the third parameter. |
DBCC CHECKDB | ensures the tables in the DB and the indexes are correctly linked. |
DBCC CHECKDALLOC | To check all pages in a DB are correctly allocated |
DBCC CHECKFILEGROUP | Checks all tables file group for any damage |
sysobjects | contains one row for each function, constraint or trigger created within a database. Indexes are not stored in this table(sysindexes). |
sysindexes | contains one row for each index and table in the database. |
ALTER TABLE | Modifies a table definition by altering, adding, or dropping columns and constraints, reassigning partitions or disabling or enabling constraints and triggers.(cannot change IDENTITY constraint) |
ORDER BY | To cause the result set to be sorted by the value in a specific column or columns. Not allowed in a CREATE VIEW Statement. |
CREATE TYPE | used to create a user-defines data type or an alias data type. |
Cartesian Product | includes a row for each possible combination of results from the other tables. the number of rows returned will equal the number of rows in one table multiplied by the number of rows in the other table. |
WITH CHECK OPTION | used to ensure that no changes to the underlying data can be made through the view that would cause data no to conform to the definitions of the view. |
WITH SCHEMABINDING | used to ensure that none of the tables references by the view are dropped or have their structure changes such that the view would not function properly. Cannot use asterisk in SELECT list., must specify column by name |
spatial index | used to optimize operations that use spatial data types, such as geometry and geography data types. |
covering index | Index that includes all columns used in the query. Can optimize performance because the query can be generated from the index without accessing the actual tables involved in the query. |
ON DELETE CASCADE | To ensure all child tables are deleted inf the parent is deleted. This can be your FOREIGN KEY constraint. |
ON DELETE NO ACTION | Would prevent a parent row from being deleted if it had a related child rows in another table. |
OPTION | used to specify query hints that will allow for optimization of a query's execution. |
What's the difference between time, date, datetime, datetime2, datetimeoffset and smalldatetime? | Time is the 24 hr clock without time zone awareness(Minimizes storage but can store time the includes hours, minutes, seconds but not fractional seconds.) |
Date is used to define 1/1 to 12/31 9999 | |
Datetime is accurate to .00333 seconds(1/1 1753 to 9999) | |
datetime2 is accurate up to 100 nanoseconds | |
datetimeoffset includes daylight savings time | |
smalldatetime(1\1 1900 to june 6, 2079)(2 bytes) does not keep track of seconds.(cant use neg numbers) | |
Time(3) stores fractional seconds, however increases storage space. | |
timestamp - is uses for row versioning, not to store time data. | |
De-normailization | is the process of stepping back through the normalization steps until you get something that is "comfortable". Improves data retrieval performance. |
Grant Execute | Gives a database user or group(defined with a role) specific permissions to data objects. Uses ON clause preceding it. |
IDENTITY | To automatically assign sequential integer values to a column |
.WRITE | used in a UPDATE statement when you need to update the values of columns that have a large object data type such as varchar(max) or varbinary(max) columns. |
SET clause | update columns with calculated values |
COMMIT statement | To commit changes made within a manual transaction to the database. |
HAVING clause | to filter the results grouped by a GROUP BY clause. Can only reference aggregate functions or column that are also specified in the GROUP BY clause. |
RESTORE DATABASE command | can be used with a previously taken full backup to recover a database. you can add a NO RECOVERY clause if you plan to apply a transaction log of differential backup as part of your recovery process. |
Heap | physical structure in non clustered index |
CREATE INDEX statement | used to define a clustered or non clustered index. |
server-scoped securable | Available across all database instances(network)(LOGIN) |
COLLATE clause | to specify sorting rules that are different than those used for other columns in the table. |
PERSISTENT clause | to create a computed column that can be included in an index. |
Define 4NF | Isolate independent multiple relationships |
A Parameter name must begin with | @ |
Full-Text index | Creates a full-text index on a table or indexed view in a database. Only one full-text index is allowed per table or indexed view, and each full-text index applies to a single table or indexed view |
Inline table | valued function includes only a single SELECT statement. |
Deterministic function | One that returns the same predictable value when called with same nvarchar(3500). Meets requirements using least amt of storage. Supports multiple language input parameters. |
INNER JOIN | returns when there is at least one match in both tables. |
What does floating-point store in relation to data types? | Real numbers |
Character stores what data type? | A-z or 0-9(any digit or letter that math functions will not be applied to) |
Boolean stores what data type? | 1 or 0, true or false |
What does ANSI SQL syntax refer to? | Grammar and rules governing the structure and content of statements. |
Graphical designers are _________ and are drag-and-drop given. | Object-Oriented |
Aggregate Functions | Return a single value, calculated from values in a column. Ex. COUNT |
What is the difference between a function and a stored procedure? | A function can be directly referenced in a select statement, and return only a single scalar or table vaule. |
What clause is required when issuing a UPDATE statement | SET |
You would include a HAVING clause in a query to: | filter the results grouped by a GROUP BY clause. |
What is the diffrence between an application role and a database role? | A database role is assigned to users |
A user-defined function | must contain a RETURNS clause and a RETURN statement. |
What is represented by a column in a well-designed relational database table | A single entity attribute |
OLTP(Online Transaction Processing) database | Is optimized to handle a large number of simultaneous updates additions and deletions. |
Good candidate for key columns in a non clustered index | Columns frequently uses as a query join conditions. |
An inline table-valued Function | Includes only a single SELECT statement. Can accept parameters. |
in a relational database, data is stored in | Multiple tables that are related using primary and foreign keys |
Which column do you need to set a value for when issuing a INSERT statement? | A column of the uniqueidentifer data type. You need to use the NEWID() function in the values list to generate the value. |
What are the three methods for whicha user can be initially identified? | Windows user logon, Membership in a windows group, SQL server logon |
How do you gather the size of a file? | 1MB = 1024KB |
1 record is 165 bytes - Multiply by amt of records. | |
A ____ backup contains only the data that has changed since the LAST backup. | Incremental |
MAX | Function returns the maximum value of an expression(IE: The maximum salary of all employees) |
STR Function does what? | returns character data converted from numeric data. |
% | Wild Card character(IE: WHERE lastname LIKE 'J%'); LIKE operator is used with % |
What does the REPLACE function do? | replaces all occurrences of the second given string in the first string expression with a third expression(SELECT REPLACE('The best TTS Solution','s','z') - The bezt TTZ .. |
Non Clustered Index | Non-clustered indexes are not copies of the table but a sorting of the columns you specify that "point" back to the data pages in the clustered index. Add non-clustered indexes for queries that return smaller result sets |
Implicit Transactions | Generates a continuous chain of transactions without stopping until completed |
Explicit transaction | An explicit transaction is one where all events of the transaction either happen together or they don't take place at all. |
ADD | A reserved Keyword and cannot be used as a object name or column name in a table unless delimited. Add is used to add a new column in a alter table statement. |
Subquery | A select statement that is nested within another SQL statement. |
SQL Server utility can view what entities | Instances of SQL server, Data-Tier apps, Databse Files, Volumes |
Between statement | Must have AND; can only admit two expressions(between(10000 and 50000)) cant add another between(10000 and 50000) and (60000 and 90000) |
Partial Backup | Backup copy of only specific file groups. |