Which statement describes the effect on an index, when the indexed column for the rows is updatedin the base table()
An update in a leaf row takes place.
B. The index becomes invalid after the update.
C. The leaf block containing the row to be updated is marked as invalid.
D. A row in the leaf block of the index for the key value is logically deleted and a new leaf row is inserted
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非晶态合金铁芯配电变压器在()时,必须采取措施。
A. 运输
B. 搬动
C. 安装运行
D. 停运
帧起始符为68H标识一帧信息的开始,其值为68H=01111000B。
A. 正确
B. 错误