Regex INSTR -Snowflake

select 
    'ygzff/afzfzh/yfzdaf/yftfrxdff/aa/ff' as input,
    regexp_instr(input, '/',1) as r1,
    regexp_instr(input, '/',2) as r2,
    regexp_instr(input, '/',3) as r3,
    r3+1;

gives:

the 1,2,3 in my example are the start offset, and result is 1 based offset the / which is the 6. thus the answer 7

The Oracle INSTR position -1 is saying count from the end, and thus is returning the position after the last instance of '/'

we can flip the string around, to find the tail, then minus if the token was found, and then use that like:

select 
    'ygzff/afzfzh/yfzdaf/yftfrxdff/aa/ff' as input,
    length(input) as l,
    regexp_instr(reverse(input), '/') as r,
    iff(r=0,0,l-(r-2)) as tp,
    substr(input, tp) as tail;

or you can also use RIGHT

select 
    column1 as input,
    length(input) as l,
    regexp_instr(reverse(input), '/') as r,
    right(input, iff(r=0,l,r-1))
from values 
    ('ygzff/afzfzh/yfzdaf/yftfrxdff/aa/ff'),
    ('no slashes here');