• Article Type: General
• Product: Aleph
• Product Version: 18.01

Description:
We see these messages in the pc_server log:

Oracle error: io_z36_write
ORA-00001: unique constraint (xxx50.Z36_ID2) violated

Resolution:
The z36_id2 is built on the z36_number (a unique number for each loan). Its value is obtained from the z52 (util g/2) last-loan-number counter. This value needs to be equal to or higher than the z36_number of any existing z36 record. You can use this SQL to find the highest z36_number:

SQL-xxx50> select max (z36_number) from z36;

If this number is higher than the last-loan-number, then use util g/2 Update to make the last-loan-number higher.

Note that the ./com_io/io_z36 program reads the last-loan-number, increments the counter, and writes the z36. If there is an error (such as the preceding), the program will re-read the z52 up to 1000 times, getting a new last-loan-number each time, in trying to find a number that works. Thus, though the "unique constraint ... Z36_ID2" message appears in the log, the program may eventually acquire a unique number and loan the item successfully.

[See also KB 8192-2157, a related problem.]