How Vertica Deletes and Updates Data

In Vertica, delete operations do not actually remove rows from physical storage. Instead, the DELETE statement marks rows as deleted.

Update operations have the same effect; the UPDATE statement actually combines delete and insert operations. The deleted rows remain in physical storage until the Tuple Mover performs a purge operation. The purge operation permanently removes deleted data so that the disk space can be reused.

For more information about how deletes and updates work in Vertica, see Mergeout in the Administrator's Guide.