Is there a PostGIS function to conditionally merge linestring geometries to the neighboring ones? - postgresql

Question

I had a lines (multilinestring) table in my PostGIS database (Postgres 11), which I have converted to linestrings and also checked the validity (ST_IsValid()) of new linestring geometries.
create table my_line_tbl as
select
gid gid_multi,
adm_code, t_count,
st_length((st_dump(st_linemerge(geom))).geom)::int len,
(st_dump(st_linemerge(geom))).geom geom
from
my_multiline_tbl
order by gid;
alter table my_line_tbl add column id serial primary key not null;
The first 10 rows look like this:
id, gid_multi, adm_code, t_count, len, geom
1, 1, 30, 5242, 407, LINESTRING(...)
2, 1, 30, 3421, 561, LINESTRING(...)
3, 2, 50, 5248, 3, LINESTRING(...)
4, 2, 50, 1458, 3, LINESTRING(...)
5, 2, 60, 2541, 28, LINESTRING(...)
6, 2, 30, 3325, 4, LINESTRING(...)
7, 2, 20, 1142, 5, LINESTRING(...)
8, 2, 30, 1425, 7, LINESTRING(...)
9, 3, 30, 2254, 4, LINESTRING(...)
10, 3, 50, 2254, 50, LINESTRING(...)
I am trying to develop the logic.
Find all <= 10 m segments and merge those to neighboring geometries
(previous or next) > 10 m
If there are many <= 10 m segments next to
each other merge them to make > 10 m segments (min length: > 10 m)
In case of intersections, merge any <= 10 m segments to the longest neighboring geometry
I thought of using SQL window functions to check the length (st_length()) of succeeding geometries (lead(id) over()), and then merging them, but the problem with this approach is, the successive IDs are not next to each other (do not intersects, st_intersects()).
My code attempt (dynamic SQL) is here, where I try to separate <= 10 and > 10 meter geometries.
with lt10mseg as (
select
id, gid_multi,
len, geom lt10m_geom
from
my_line_tbl
where len <= 10
order by id
), gt10mseg as (
select
id, gid_multi,
len, geom gt10m_geom
from
my_line_tbl
where len > 10
order by id
)
select
st_intersects(lt10m_geom,gt10m_geom)
from
lt10mseg, gt10mseg
order by id
Any help/suggestions (dynamic SQL/PLPGSQL) to continue develop the above logic? The ultimate goal is to get rid of <= 10 m segments by merging them to the neighbors.