Global Deduplication

Global Deduplication

Global Deduplication

Global deduplication compares files across the entire collection, so a document held by ten custodians is reviewed once. Custodian deduplication suppresses copies only within each individual's data, reviewing the document once per custodian.

Global produces substantially greater volume reduction.

Alternative Names:

Cross-Custodian Deduplication, Horizontal Deduplication

Why it Matters?

Global deduplication reduces review cost significantly but requires that custodian tracking be preserved, since the suppressed copies establish who possessed the material. The choice should be made at the ESI protocol stage rather than after processing, because reversing it requires reprocessing. Requesting parties sometimes prefer custodian-level deduplication precisely to see possession patterns in the production itself.

Frequently asked questions

What is the difference from custodian deduplication?

What is the difference from custodian deduplication?

Global compares across all custodians so a document is reviewed once total. Custodian deduplication reviews it once per person who held it.

Why would a requesting party prefer custodian-level?

Why would a requesting party prefer custodian-level?

Because possession patterns are visible in the production itself rather than requiring reference to suppressed-copy metadata.