单选题Which statement is true regarding Flashback Version Query？（）AIt returns versions of rows only within a transaction.BIt can be used in subqueries contained only in a SELECT statement.CIt will return an error if the undo retention time is less than the l

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单选题

Which statement is true regarding Flashback Version Query？（）

It returns versions of rows only within a transaction.

It can be used in subqueries contained only in a SELECT statement.

It will return an error if the undo retention time is less than the lower bound time or SCN specified.

It retrieves all versions including the deleted as well as subsequently reinserted versions of the rows.

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第1题

You are maintaining your OLTP database in Oracle10g. You are performing the Flashback Transaction Query to find the undo SQL statements that can be used to undo the changes made to the database in the specific time period. Which pseudocolumn will you use to perform the Flashback Transaction Query？（）A、 VERSIONS_STARTSCNB、 VERSIONS_STARTTIMEC、 VERSIONS_XIDD、 VERSIONS_OPERATION

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第2题

Which two are true about aggregate functions? （）A、You can use aggregate functions in any clause of a SELECT statement.B、You can use aggregate functions only in the column list of the select clause and in the WHERE clause of a SELECT statement.C、You can mix single row columns with aggregate functions in the column list of a SELECT statement by grouping on the single row columns.D、You can pass column names, expressions, constants, or functions as parameter to an aggregate function.E、You can use aggregate functions on a table, only by grouping the whole table as one single group.F、You cannot group the rows of a table by more than one column while using aggregate functions.

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第3题

Which two statements are correct regarding the Flashback Versions Query feature？（）A、 You can use this feature to identify the committed versions of the rows， but not the uncommitted versions.B、 You can use this feature to identify the versions of V$ views.C、 You can use this feature to identify the inserts， deletes， and updates performed on a particular row but not the data definition language （DDL） operations performed on the table.D、 You can use this feature for a table only if row movement is enabled for the table.E、 You can use this feature to identify the versions of external and fixed tables.

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第4题

What is true regarding subqueries?（）A、The inner query always sorts the results of the outer queryB、The outer query always sorts the results of the inner queryC、The outer query must return a value to the outer queryD、The inner query returns a value to the outer queryE、The inner query must always return a value or the outer query will give an error

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第5题

Which two statements are true regarding subqueries? （）A、A subquery can retrieve zero or more rows B、Only two subqueries can be placed atone level C、A subquery can be used only in SQL query statements D、A subquery can appear on either side of a comparison operator E、There is no limit on the number of subquery levels in the WHERE clause of a SELECT statement

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第6题

Which two statements about subqueries are true? （）A、A single row subquery can retrieve data from only one table.B、A SQL query statement cannot display data from table B that is referred to in its subquery, unless table B is included in the main query's FROM clause.C、A SQL query statement can display data from table B that is referred to in its subquery, without including B in its own FROM clause.D、A single row subquery can retrieve data from more than one table.E、A single row subquery cannot be used in a condition where the LIKE operator is used for comparison.F、A multiple-row subquery cannot be used in an INSERT statement to insert multiple rows at a time.

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第7题

Which statement is true regarding Flashback Version Query？（）A、 It returns versions of rows only within a transaction.B、 It can be used in subqueries contained only in a SELECT statement.C、 It will return an error if the undo retention time is less than the lower bound time or SCN specified.D、 It retrieves all versions including the deleted as well as subsequently reinserted versions of the rows.

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单选题Which statement is true regarding Flashback Version Query？（）A It returns versions of rows only within a transaction.B It can be used in subqueries contained only in a SELECT statement.C It will return an error if the undo retention time is less than

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更多“单选题Which statement is true regarding Flashback Version Query？（）A It returns versions of rows only within a transaction.B It can be used in subqueries contained only in a SELECT statement.C It will return an error if the undo retention time is less than”相关问题

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