Re: [PATCH] Proof of concept for GUC improvements

The following review has been posted through the commitfest application:
make installcheck-world:  tested, passed
Implements feature:       tested, passed
Spec compliant:           tested, passed
Documentation:            not tested

Hi

I quite like the feature this patch provides, it makes special int values more meaningful to user. I like that you
addeda configuration to allow the original int value to be outputted or the special value, this adds some flexibility
incase returning special value breaks some old applications. I scanned through the GUC list and found that the
followingparameters can potentially be categorized in the "special_disabled0" group,
 
just for your reference.

max_prepared_transactions
vacuum_cost_delay
effective_io_concurrency
max_parallel_workers
max_parallel_maintenance_workers
max_parallel_workers_per_gather
max_logical_replication_workers
max_sync_workers_per_subscription
jit_above_cost
jit_inline_above_cost
jit_optimize_above_cost
log_rotation_age
log_rotation_size
log_transaction_sample_rate

Cary Huang
-----------------
HighGo Software Canada
www.highgo.ca