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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单选题You executed the following query： SELECT operation， undo_sql， table_name FROM flashback_transaction_query； Which statement is correct regarding the query output？（）A It would return information regarding only the last committed transaction.B It would return only the active transactions in all the undo segments in the database.C It would return only the committed transactions in all the undo segments in the database.D It would return both active and committed transactions in all the undo segments in the database.E It would return information regarding the transactions that began and were committed in the last 30 minutes.

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多选题Which two statements about subqueries are true? （）AA single row subquery can retrieve data from only one table.BA 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.CA SQL query statement can display data from table B that is referred to in its subquery, without including B in its own FROM clause.DA single row subquery can retrieve data from more than one table.EA single row subquery cannot be used in a condition where the LIKE operator is used for comparison.FA multiple-row subquery cannot be used in an INSERT statement to insert multiple rows at a time.

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第4题

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单选题By mistake， you ran the batch job （for updating the BILL_DETAILS table） twice. You are not sure which rows in the BILL_DETAILS table were affected. You need to identify： a） A list of changes made along with the transaction identifier of each change. b） The necessary SQL statements to undo the erroneous changes. Which option would you choose？（）ARMAN only.BFlashback Table only.CFlashback Version Query only.DFlashback Database and Flashback Transaction Query.EFlashback Version Query and Flashback Transaction Query.

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单选题You executed the following query： SELECT operation， undo_sql， table_name FROM flashback_transaction_query； Which statement is correct regarding the query output？（）AIt would return information regarding only the last committed transaction.BIt would return only the active transactions in all the undo segments in the database.CIt would return only the committed transactions in all the undo segments in the database.DIt would return both active and committed transactions in all the undo segments in the database.EIt would return information regarding the transactions that began and were committed in the last 30 minutes.

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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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