Recursive Efficiency!

Question

User439975351 posted

Hi all,

I'm trying to speed up a hierarchical tree builder with LINQ, this is what I have but it takes ages for trees that are thousands deep! Any tip on speeding this up at all?

void TreeBuilder(IEnumerable<Tree> data, int? id = null)
            {
                var items = data.Where(d => d.parentId == id).OrderBy(o => o.id);
                if (items.Any())
                {
                    foreach (var item in items)
                    {
                        teamList.Add(Tuple.Create(item.id, Convert.ToInt32(item.parentId)));
                        TreeBuilder(data, item.id);
                    } 
                }
            }

Answer 1

User753101303 posted

Hi,

Thousands deep really ? How many rows do you finally return? What is your db? In SQL Server you could consider using https://technet.microsoft.com/en-us/library/ms186243(v=sql.105).aspx or https://docs.microsoft.com/en-us/sql/relational-databases/hierarchical-data-sql-server

You could also consider to expand each node as needed. Do you really need to get  the full tree especially if it is really that complex...

Answer 2

User439975351 posted

It varies per team but 3000 is not uncommon! MS SQL Server

The stakeholders want to see the whole tree!

Answer 3

User-707554951 posted

Hi  1jus

From your description, You get result you want correctly

Then you want know how to improve the Efficiency of the piece of code.

As far as in know, you code has high efficiency yet. so there is no need for you to figure out a way to speed it up:

Best regards

Cathy