1Z0-051 20. Which three statements are true regarding the data types in Oracle Database 10g/11g?

20. Which threestatements are true regarding the data types in Oracle Database 10g/11g?(Choose

three.)

A. Only one LONG column can be used per table.

B. A TIMESTAMPdata type column stores only time values with fractional seconds.

C. The BLOB datatype column is used to store binary data in an operating system file.

D. The minimum column width that can be specified for aVARCHAR2 data type column is one.

E. The value for a CHAR data type column is blank-padded tothe maximum defined column width.

Answer: ADE

Long类型字段一个表只能有一个,不能使用子查询拷贝,不能使用在order by和group by子句中,并且long类型的字段不能有约束。所以A正确



Timestamp类型的列,默认秒后边跟六位,最多可跟九位,也可没有小数秒。所以B说只能跟小数秒是错误的。

1Z0-051 20. Which three statements are true regarding the data types in Oracle Database 10g/11g?_第1张图片

BCLOB是存的二进制文件,bfile存的是外部的二进制文件即操作系统文件,所以C说bclob存的是操作系统二进制文件是错的。

D说varchar2最小可指定的宽度为1,最大为4000。E说char类型可以不指定也可以指定最大宽度,char不指定宽度默认为1,最大为2000.

所以DE是正确的

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