Summary
Merging many PDFs that each carry named destinations is quadratic in the accumulated number of destinations, rather than linear in the input size. On a 160-file merge with 250 named destinations each (40,000 total), named-destination handling accounts for 99.8% of merge time — 59.0s out of 59.1s.
The behaviour is unchanged between 5.1.0 and 6.16.1.
Summary
Merging many PDFs that each carry named destinations is quadratic in the accumulated number of destinations, rather than linear in the input size. On a 160-file merge with 250 named destinations each (40,000 total), named-destination handling accounts for 99.8% of merge time — 59.0s out of 59.1s.
The behaviour is unchanged between 5.1.0 and 6.16.1.