Identify two situations in which the block header grows in a data block. (Choose two.) 选项 A.when ro

Identify two situations in which the blockheader grows in a data block. (Choose two.)
选项
A.when row directories need more row entries
B.when there is rowmigration in the data block
C.when there is anincrease in the PCTFREE value for the data block
D.when more transaction slots are required than are initiallyconfigured

A: 正确,行目录需要更多的行条目时块头会增长
B: 错误,迁移行的rowid不变,行迁移不会使块头增长
C: 错误,PCTFREE参数设置为更新操作在块头预留多少空间,不会使块头增长
D: 正确,需要更多事务槽的时块头会增长