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由于()能软化骨骼和脱钙,破坏钙元素在人体内的动态平衡,使受伤肢体酸软、疼痛加剧,因此,骨折治疗和康复期间应避免吃。
A . 糖
B . 醋
C . 酒精
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Which of the following cannot be used as input to the SQL Tuning Advisor?() (Choose all that apply.)
A . A single SQL statement provided by a user
B . An existing SQL Tuning Set (STS)
C . A preprocessed Database Replay workload
D . A schema name
E . SQL statement identified in EM as using excessive resource
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When executing a SQL workload, you choose to generate execution plans only, without collecting execution statistics. Which two statements describe the implications of this? ()(Choose two.)
A . It produces less accurate results of the comparison analysis.
B . It automatically calls the SQL Tuning Advisor for recommendations.
C . It shortens the time of execution and reduces the impact on system resources.
D . Only the changes in the execution plan, and not performance regression, are detected.
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系统内各元素的关系有些是(),有些是动态变化的。
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What two statements are true regarding the recommendations received from the SQL Access Advisor?()(Choose two.)
A . It cannot generate recommendations that support multiple workload queries.
B . It can recommend partitioning on tables provided that the workloads have some predicates and joins on the columns of the NUMBER or DATE type.
C . It can recommend partitioning only on tables that have at least 10,000 rows.
D . It can recommend only B-tree indexes and not bitmap or function-based indexe
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When executing a SQL workload,you choose to generate execution plans only, without collecting execution statistics. Which two statements describe the implications of this?()
A . It produces less accurate results of the comparison analysis.
B . It automatically calls the SQL Tuning Advisor for recommendations.
C . It shortens the time of execution and reduces the impact on system resources.
D . Only the changes in the execution plan,and not performance regression,are detected.
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Which two statements about the SQL Management Base (SMB) are true? ()(Choose two.)
A . It contains only SQL profiles generated by SQL Tuning Advisor.
B . It stores plans generated by the optimizer using a stored outline.
C . It is part of the data dictionary and stored in the SYSAUX tablespace.
D . It is part of the data dictionary and stored in the SYSTEM tablespace.
E . It contains the statement log, the plan history, plan baselines, and SQL profiles.
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Which three functions are performed by the SQL Tuning Advisor?() (Choose three.)
A . Building the SQL profile
B . Recommending optimization of materialized views
C . Checking query objects for missing and stale statistics
D . Recommending bitmap, function-based, and B-tree indexes
E . Recommending restructuring SQL queries that are using bad pla
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What recommendations does the SQL Access Advisor provide for optimizing SQL queries? ()(Choose all that apply.)
A . selection of SQL plan baselines
B . partitioning of tables and indexes
C . creation of index-organized tables
D . creation of bitmap, function-based, and B-tree indexes
E . optimization of materialized views for maximum query usage and fast refresh
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In Oracle 11g, which recommendations does the SQL Access Advisor generate? ()(Choose all that apply.)
A . partitioning recommendations
B . statistics collection recommendations
C . index creation recommendations
D . materialized view recommendations
E . materialized view log recommendatio
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在SQL Server数据库中,T-SQL语言是由()和增加的语言元素组成的。
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在MyBatis中元素用于单条件分支判断,当某个的test属性判断成立,然后跳过其他元素进行动态SQL组装。
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【填空题】使用<set>和<if>元素相结合的方式来组装update语句时,<set>元素就会动态前置【 】关键字,同时也会消除SQL语句中最后一个多余的【 】
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动态SQL语句是指在SQL程序编译时其中有些部分尚未确定,需要在程序的【】过程中临时生成的SQL语句。
动态SQL语句是指在SQL程序编译时其中有些部分尚未确定,需要在程序的【 】过程中临时生成的SQL语句。
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mybatis在sql优化上相对于hibernate有更大的选择()
是
否
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有关MyBatis配置文件中 元素的说明正确的是()
A.是一个配置属性的元素,该元素通常用来将内部的配置外在化,即通过外部的配置来动态的替换内部定义的属性
B.通常可以使用 元素的resource属性引入外部常量配置文件
C.除了可以使用 元素的resource属性引入外部常量配置文件,还可以通过 元素的子元素 来获取属性值
D.使用properties配置文件来配置属性值可以方便地在多个配置文件中使用这些属性值,并且方便日后的维护和修改
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mybatis的动态sql技术可以为代码的改良奠定一定的基础()
是
否
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3、对于正在使用的动态数组a(n),要增加3个数组元素,又要保留原来数组中的值,则下列语句正确的是___________。
A.Dim a(n+3)
B.ReDim a(n+3)
C.Dim Preserve a(n+3)
D.ReDim Preserve a(n+3)
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resultMap是MyBatis映射文件中最重要也是最强大的元素,包含了一些子元素主要有()
A.id
B.result
C.association
D.collection
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以下有关MyBatis映射文件中<insert>元素说法正确的是。
A、<insert>元素用于映射插入语句,在执行完元素中定义的SQL语句后,没有返回结果。
B、<insert>元素的属性与<select>元素的属性相同。 C、keyColumn属性用于设置第几列是主键,当主键列不是表中的第一列时需要设置。 D、useGeneratedKeys(仅对insert有用)此属性会使MyBatis使用JDBC的getGeneratedKeys()方法来获取由数据库内部生产的主键。3、【单选题】以下关于</select>元素及其属性说法错误的是。
A、<select>元素用来映射查询语句,它可以帮助我们从数据库中读取出数据,并组装数据给业务开发人员 B、parameterType属性表示传入SQL语句的参数类的全限定名或者别名 C、resultMap表示外部resultMap的命名引用,返回时可以同时使用resultType和resultMap D、在同一个映射文件中可以配置多个</select>元素
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【填空题】MyBatis映射文件中<insert>的<selectKey>子元素的order属性可以被设置为【 】或【 】
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23、MyBaits中对原始SQL中的“where 1=1”的条件可以使用<where>与<if>元素组合进行替换。()
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【单选题】以下有关MyBatis映射文件中<insert>元素说法正确的是。
A.<insert>元素用于映射插入语句,在执行完元素中定义的SQL语句后,没有返回结果。
B.<insert>元素的属性与<select>元素的属性相同。
C.keyColumn属性用于设置第几列是主键,当主键列不是表中的第一列时需要设置。
D.useGeneratedKeys(仅对insert有用)此属性会使MyBatis使用JDBC的getGeneratedKeys()方法来获取由数据库内部生产的主键。
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以下有关<sql>元素说法错误的是()
A.<sql>元素的作用就是定义可重用的SQL代码片段,然后在其他语句中引用这一代码片段
B.使用<include>元素的refid属性可以引用自定义的代码片段
C.使用<include>元素refid的属性值为自定义代码片段的name
D.<sql>元素是<mapper>元素的子元素