Descending Sequences
Jim_Knicely
Administrator
The default increment for a Vertica sequence 1. But you can also create a sequence that has a negative increment so that you can have a count down.
Example:
dbadmin=> CREATE SEQUENCE up_seq; CREATE SEQUENCE dbadmin=> SELECT up_seq.NEXTVAL; NEXTVAL --------- 1 (1 row) dbadmin=> SELECT up_seq.NEXTVAL; NEXTVAL --------- 2 (1 row) dbadmin=> SELECT up_seq.NEXTVAL; NEXTVAL --------- 3 (1 row) dbadmin=> CREATE SEQUENCE down_seq START WITH 3 INCREMENT BY -1; CREATE SEQUENCE dbadmin=> SELECT down_seq.NEXTVAL; NEXTVAL --------- 3 (1 row) dbadmin=> SELECT down_seq.NEXTVAL; NEXTVAL --------- 2 (1 row) dbadmin=> SELECT down_seq.NEXTVAL; NEXTVAL --------- 1 (1 row) dbadmin=> SELECT down_seq.NEXTVAL; ERROR 4705: Sequence exceeded min value
Helpful Links:
https://www.vertica.com/docs/9.2.x/HTML/Content/Authoring/AdministratorsGuide/Sequences/Sequences.htm
https://www.vertica.com/docs/9.2.x/HTML/Content/Authoring/SQLReferenceManual/Statements/CREATESEQUENCE.htm
Have fun!
0