Re: Inefficiency in parallel pg_restore with many tables

Here is a work-in-progress patch set for converting ready_list to a
priority queue.  On my machine, Tom's 100k-table example [0] takes 11.5
minutes without these patches and 1.5 minutes with them.

One item that requires more thought is binaryheap's use of Datum.  AFAICT
the Datum definitions live in postgres.h and aren't available to frontend
code.  I think we'll either need to move the Datum definitions to c.h or to
adjust binaryheap to use "void *".

[0] https://postgr.es/m/3612876.1689443232%40sss.pgh.pa.us

-- 
Nathan Bossart
Amazon Web Services: https://aws.amazon.com