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Technical Article   FAQ:  What are the SDE db_ev_* triggers used for with Oracle?

Article ID: 34982
Software:  ArcSDE 9.3, 9.3.1
Platforms: N/A

Question

What are the SDE db_ev_* triggers used for with Oracle?

Answer

The sde schema's db_ev_alter_st_metadata, db_ev_drop_st_metadata, and db_ev_rename_metadata triggers are database event triggers used to maintain the st_geometry metadata tables when tables containing st_geometry attributes are altered, dropped, or renamed.

The db_ev_alter_st_metadata trigger is executed after every ALTER TABLE command in the database. The trigger first checks if the table being altered is registered as an st_geometry table, and if it is, updates the metadata accordingly based upon the event.

The db_ev_drop_st_metadata trigger is executed after every DROP TABLE command in the database. The trigger checks if the table being dropped contains an st_geometry attribute; if yes, the trigger removes the metadata from the st_geometry_columns and st_geometry_index tables.

The db_ev_rename_st_metadata trigger is executed after every RENAME command in the database. The trigger checks if the table being renamed contains an st_geometry attribute; if yes, the trigger updates the metadata to reflect the new name of the table.

These triggers should never be modified or removed from the sde schema or the st_geometry metadata will not be correctly maintained as schema changes occur in the Oracle instance.

Created: 6/9/2008
Last Modified: 5/3/2011

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