考题
Excel 2003的默认工作表分别命名为()A:Sheetl,Sheet2,Sheet3,Sheet4,Sheet5B:Book1,Book2,Book3,Book4,Book5C:Table1,Table2,Table3,Table4,Table5D:List1,List2,List3,List4,List5
考题
Youexecutedthefollowingcommands:SQLALTERSESSIONSETOPTIMIZER_USE_PENDING_STATISTICS=false;SQLEXECUTEDBMS_STATS.SET_TABLE_PREFS(’SH’,’CUSTOMERS’,’PUBLISH’,’false’);SQLEXECUTEDBMS_STATS.GATHER_TABLE_STATS(’SH’,’CUSTOMERS’);WhichstatementiscorrectregardingtheabovestatisticscollectionontheSH.CUSTOMERStableintheabovesession?()A.Thestatisticsarestoredinthependingstatisticstableinthedatadictionary.B.Thestatisticsaretreatedasthecurrentstatisticsbytheoptimizerforallsessions.C.Thestatisticsaretreatedasthecurrentstatisticsbytheoptimizerforthecurrentsessionsonly.D.Thestatisticsaretemporaryandusedbytheoptimizerforallsessionsuntilthissessionterminates.
考题
On your Oracle Database, you issue the following commands to create indexes:SQL CREATE INDEX oe.ord_customer_ix1 ON oe.orders (customer_id, sales_rep_id) INVISIBLE;SQL CREATE BITMAP INDEX oe.ord_customer_ix2 ON oe.orders (customer_id, sales_rep_id);Which two statements are true?()A. Only the ORD_CUSTOMER_IX1 index created.B. Both the indexes are updated when a row is inserted, updated, or deleted in the ORDERS table.C. Both the indexes are created: however, only ORD_CUSTOMERS_IX1 is used by the optimizer for queries on the ORDERS table.D. The ORD_CUSTOMER_IX1 index is not used by the optimizer even when the OPTIMIZER_USE_INVISIBLE_INDEXES parameters is set to true.E. Both the indexes are created and used by the optimizer for queries on the ORDERS table.F. Both the indexes are created: however, only ORD_CUSTOMERS_IX2 is used by the optimizer for queries on the ORDERS table.
考题
Examine this command:SQL exec DBMS_STATS.SET_TABLE_PREFS (‘SH’, ‘CUSTOMERS’, ‘PUBLISH’, ‘false’);Which three statements are true about the effect of this command?()
A. Statistics collection is not done for the CUSTOMERS table when schema stats are gathered.B. Statistics collection is not done for the CUSTOMERS table when database stats are gathered.C. Any existing statistics for the CUSTOMERS table are still available to the optimizer at parse time.D. Statistics gathered on the CUSTOMERS table when schema stats are gathered are stored as pending statistics.E. Statistics gathered on the CUSTOMERS table when database stats are gathered are stored as pending statistics.
考题
找出"作者"库表中没有出现在"获奖名单"库表中的所有作者信息的SQL语句,(提示:使用NOT IN,NOT EXISTS,以及外部连接(+)三种方法),并说明那种方法是不优化的出版社: 出版社代码 char(2),出版社名称 varchar2(32)图书: 图书编号 char(8),图书名称 varchar2(128),出版社代码 char(2),作者代号char(4),图书简介 varchar2(128)作者: 作者代号 char(4),作者名称 varchar2(10),性别 char(1),年龄 number(3),文学方向 varchar2(64)获奖名单: 获奖日期 date,获奖人员 char(4)
考题
Excel的默认工作表分别命名为______。
A.Sheetl,Sheet2,Sheet3,Sheet4,Sheet5B.Table1,Table2,Table3,Table4,Table5C.List1,List2,List3,List4,List5D.Book1,Book2,Book3,Book4,Book5
考题
Examinethecommand:SQLDBMS_STATS.SET_TABLE_PREFS(’SH’,’CUSTOMERS’,’PUBLISH’,’false’);Whichstatementdescribestheeffectoftheabovecommand()
A.AutomaticstatisticscollectionisstoppedfortheCUSTOMERStable.B.StatisticsfortheCUSTOMERStablearelockedandcannotbeoverwritten.C.ExistingstatisticsfortheCUSTOMERStablebecomeunusableforthequeryoptimizer.D.Subsequently,statisticsgatheredontheCUSTOMERStablearestoredaspendingstatistics
考题
将students中的列变量重新命名为: (1)id_number, name, gender, score, has_graduate (2)选出Bob的性别gender,并存入变量bob_gender (3)选出列has_graduate,并存入向量status (4)创建数据框part_df,其中包含前三个学生的所有信息 (5)创建数据框rest_df,包含其余学生的所有信息
考题
23、假定 number=4,下面哪个语句不会出错?A.print(format(number, "2d"), format(number ** 1.5, "4d"))B.print(format(number, "2d"), format(number ** 1.5, "4.2d"))C.print(format(number, "2d"), format(number ** 1.5, "4.2f"))D.print(format(number, "2f"), format(number ** 1.5, "4.2d"))
考题
16、MySQL数据库中,通常将用户写入对应的权限表来控制访问权限的,以下属于用户权限得选项()。A.UserB.dbC.table_privD.columns_priv