• Article Type: General
• Product: Aleph
• Product Version: 20, 21, 22, 23

Description:
In the pc_server log, these series of errors display:
Oracle error: io_sequence_next
ORA-02289: sequence does not exist
Oracle error: io_znn_write
ORA-00001: unique constraint (xxx50.Znn_ID) violated
where "io_znn_write" is: io_z309_write, io_z31_write, io_z45_write, io_z601_write, or io_z71_write. And "xxx50" is your ADM library.
What do we do about this error?

Resolution:
This error indicates that the last_record_sequence is not defined in the $pw_library.
This sequence is used by the five tables shown above as part of their record key (to make the key unique). (*See more in Additional Information below.)  The last_record_sequence is in the delivered ./aleph/tab/file_list.PW $pw_library file_list template and looks like this:
SEQ last_record_sequence
If you have a $pw_library file_list, you should add the above line to it.
If your $pw_library file_list is blank and you are using the default ./aleph/tab/file_list.PW, it already has this line.
What you *do* need to do in either case is:
> dlib abcde <where "abcde" is your $pw_library>
> util a, 17, 9 ("Sequences")
> Enter sequence name to Create (all/sequence-name): all
To verify that the sequence has been created successfully, do:
> s+ abcde <where "abcde" is your $pw_library>
abcde@ALEPH20> select SEQUENCE_OWNER, SEQUENCE_NAME from all_sequences where SEQUENCE_OWNER like 'ABC%';
**** Hit return to continue ****
SEQUENCE_OWNER SEQUENCE_NAME
------------------------------ ------------------------------
ABCDE LAST_PUBLISH_SEQ
ABCDE LAST_RECORD_SEQUENCE
ABCDE LAST_RESULT_SET

Note: The "Create/recreate all library sequences" is a standard step in the "How To Open a Library" procedures, but is sometimes overlooked.