OCP question analysis _ 007: Sequence

OCP question analysis _ 007: sequence can be designed to be unique, but continuous instances cannot be implemented. sequence disconnection number, transaction rollback, sequence disconnection number, concurrent access, sequence may be disconnected ...... www.2cto.com calls seq_name.currval, the returned result is the returned value of seq_name.nextval, which is the last time seq_name.nextval is called in this session. Therefore, when seq_name.currval is called separately, you must ensure that seq_name.nextval is called in this session before this) www.2cto.com if seq_name.currval and seq_name.nextval appear in the same SQL statement, run seq_name.nextval first, and then run explain. Therefore, the return values of the two should be equal. Ents about sequences are true? (Choose two .) a. you use a NEXTVAL pseudo do column to look at the next possible value that wocould be generated from a sequence, without actually retrieving the value. b. you use a CURRVAL pseudo do column to look at the current value just generated from a sequence, without affecting the further values to be generated from the sequence. c. you use a NEXTVAL pseudo do column to obtain the next possible value from a sequence by actually retrieving the value from the sequence. d. you use a CURRVAL pseudo do column to generate a value from a sequence that wocould be used for a specified database column. e. if a sequence starting from a value 100 and incremented by 1 is used by more than one application, then all of these applications cocould have a value of 105 assigned to their column whose value is being generated by the sequence. f. you use a REUSE clause when creating a sequence to restart the sequence once it generates the maximum value defined for the sequence. answer: B, C