Algumas perguntas e respostas preparatórias para uma das provas sobre Oracle 9i

Veja algumas perguntas e respostas selecionadas pelo autor para uma das provas de certificação Oracle 9i.

por Márcio Novelli

Desculpe a demora pessoal pela minha coluna, mas estou com projetos em andamento sobre um livro que vou fazer parte sobre oracle.…

Neste artigo envio algumas perguntas e respostas preparatórias para uma das provas Oracle 9i.

P: identify the feature of an implicit lock
R: implicit locks are autmotically implemented

P: identify the purpose of implementing read consistency
R: to ensure that users do not view data that is being changed

P: identify the period for which the server retains the previos state of data when you perform dml operations
R: until the transaction ends

P: identify the statment that you use to make all data changes permanent
R: commit

P: identify the option that indicates the beginning of a transaction
R: when the first execute sql statement is encountered

P: identify the constraint that must be enforced on a column for

P: identify the column uniquely in an update statment
R: primary key

P: identify the action performed by the server if you omit the where clause in a delete statement
R: all the rows in the table are deleted

P: identify the structure that generates a series of unique values
R: sequence

P: what command can you use to display information in the header section of everfy page in a report?
R: ttitle

P: identify the special characters that can be used for naming an oracle database object?
R: $ or a # symbol - $ #

P: identify the action performed the oracle server if you omit the column list in the insert statement
R: the server assumes the default column sequence

P: identify the function that you use to insert the current date into a column
R: sysdate

P: identify the keywords used in dml statments
R: insert,update,delete

P: identify the feature of a user table
R: created and managed by users

P: identify the action that the server perfoms when a primary key value is deleted from the primary key table
R: the server deletes the value from the primary key cache

P: identify a feature of a table level constraint?
R: a table level constraint can reference one or more colummns

P: identify the rule for referencing objects in another users"s schema
R: you must have rights to acess objects from anothers user"s schema

P: identify the maximum character lenght that can be specifield for the varchar2 datatype?
R: 4000

P: identify the datatype used specify the time zone dislacement between the local time and utc ?
R: timestamp with local zone

P: identify the datatype that stores large and unstructured data
R: lob

P: identify the feature of a primary key?
R: a pk ensures a unique value for every row in a column

P: identify a property of a constraint
R: constraints are enforced at the database level

P: what type of subquery can you use to return values from both the employee_id and department_id columns ?
R: multiple-column sub-query

P: what command is used to divide rows of data into sections with line feeds and suppress duplicate rows
R: break

P: identify the components of a relacional database model
R: a collection of relations a set of operations,and data integrity rules

P: identify the element that uniquely identifies a row in a table
R: primary key

P: identify the phase in which you refine the prototype
R: transition

P: identify the phase in the system development cycle during which the er model us used
R: strategy and analysis phase

P: identify the convention that indicates that the relationship between the entities in mandatory
R: a solid line

P: identify a feature of oracle 9i
R: oracle 9i provides faster failure detection thus reducing downtime

P: identify the feature of oracle9i that ensures that failure of one security mechanism does not totally tamper critical information
R: deep data protection

P: identify the language that is used to manipule date in the oracle server
R: sql

P: identify the sql statement that is used to retrieve data from one or more tables
R: select

P: when the exists operator returns a value of true, it indicates that?
R: at least one row value returned by the subquery exists in the outer query

P: what is the firts step in processing a correlated subqyery?
R: a candidate row is retrieved by the main query

P: what is the manin advantage of creating a query block by using the with clause ?
R: it can be used multiple times in the same query

P: the in operator checks whether a value specifield in the where clause of an outer query in the same as any in a list of values returned by a sybquery
R: in

P: what comparison operator can be used with a subquery to return a single value ?
R: the greater-that(>)operator

P: when a query containing a subquery is executed, the outer query uses the result of the subquery in the where clause
R: a subquery is a select statment that is: embledded in a clause of another sql statement

P: what function can you use to obtain information about a summary value?
R: grouping

P: which set operator does not sort the output automatically ?
R: union all

P: which set operator can be used to return all rows that are common to both queries ?
R: intersect

P: which set operator includes duplicate rows in the result set ?
R: union all

P: what type of sql:1999 join in used to return all the rows from one table, as well as any unmatched rows from a second table ?
R: outer join

P: what of sql:1999 join is used to display all rows from two tables that have the same column names and data type ?
R: natural join

P: what type of join be used to link data from two tables that contain common values ?
R: equijoin

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