Using NEXTVAL or CURRVAL to Query Global Sequence Numbers¶
NEXTVAL returns the next sequence number, and CURRVAL returns the current sequence number. nextval(n) returns n unique sequence numbers.
nextval(n) can be used only in select sequence.nextval(n) and does not support cross-schema operations.
currval(n) is not supported.
Procedure¶
Log in to the required DDM instance using a client.
Open the required schema.
Run the following command to create a global sequence:
create sequence seq_test;
Run the following command to obtain the next sequence number:
select seq_test.nextval;
Run the following command to obtain the current sequence number:
select seq_test.currval;
Run the following command to obtain sequence numbers in batches:
select seq_test.nextval(n);
Note
Cross-schema operations are not supported when sequence numbers are obtained in batches.
If no global sequence is used, CURRVAL returns 0.