What Is The Job Name EU_REORG Meant?

OSS is your friend - see note 18023:

1. When starting Transaction SE80 for the first time, the three EU jobs are scheduled automatically: EU_INIT (single start), EU_REORG (periodically each night), and EU_PUT (periodically each night).

Alternatively,those three EU jobs can also be scheduled by manually executing program SAPRSEUJ.

Shortdescription of the individual jobs:

EU_INIT:

EU_INIT serves for completely rebuilding the indices and therefore has a correspondingly long runtime. It starts program SAPRSEUI. All customer-defined programs (selection according to the name ranges) are analyzed, and an index is created that is used in the DW for the where-used lists for function modules, error messages, reports, etc.

Starting in Release 2.1, this index is automatically updated online. The job can be repeated at any time. After a termination, the job is automatically scheduled for the next day; it then starts at the point oftermination. (EU_INIT can therefore be terminated deliberately, if it disturbsother activities in the system.)

EU_REORG:

As mentioned above, the indices are automatically updated online by the tools. To keep the effort for updating these indices as low as possible, only the changes are logged, which means a reorganization of the complete index for each program is required from time to time. To avoid having this reorganization interfere with online work, job EU_REORG runs every night and performs this task. If job EU_REORG did not run one night, this simply means that thereorganization takes place more often online.