TRUNCATE is often recommended over DELETE in PostgreSQL for performance reasons due to the following:

1. Efficiency: TRUNCATE is more efficient, especially for large tables. It quickly removes all rows from a table by un-linking the data files rather than individually deleting rows.
2. Less Lock Overhead: TRUNCATE requires fewer locks. It typically locks the table structure only, whereas DELETE locks each row as it is being deleted.
3. Reduced Transaction Log Usage: TRUNCATE generates fewer transaction logs compared to DELETE. DELETE logs every row change, which can bloat the transaction log and slow down the operation in large tables.
4. No Trigger Execution: TRUNCATE does not activate triggers for each row deletion, which can be a significant time saver when compared to DELETE.
5. Immediate Space Reclamation: TRUNCATE immediately reclaims space used by the table (except for minimal space reserved for the table structure), whereas DELETE requires subsequent vacuuming to reclaim space.

Due to these factors, TRUNCATE is generally faster and more efficient for removing all rows from a table. However, TRUNCATE cannot be used if you need conditional deletes or rely on triggers for row-level operations.