--db2z-databasechangelog-index is a global parameter that specifies the index name for the DATABASECHANGELOG table on DB2 z/OS. There is no default value; you must provide the index name explicitly.

On DB2 z/OS, when Liquibase creates tracking tables in a pre-existing tablespace, Db2 does not implicitly create the required index. Without an index, the DATABASECHANGELOG table is left in an unavailable state, which prevents Liquibase from running. You must set --db2z-databasechangeloglock-index, --db2z-databasechangelog-index, --db2z-tracking-tables-location-tablespace, and (if applicable) --db2z-tracking-tables-location-database together. When placing tracking tables in a pre-existing tablespace, you must set all four parameters together to ensure Liquibase can locate the tablespace and create the required indexes. Omitting any of these parameters may leave the tracking tables unavailable or prevent Liquibase from running.