[GENERAL] Is EXISTS the most efficient approach for PostgreSql to check for existence of nodes in a tree?

I have a key value table in my Postgresql db, which represents hierarchical data through parent_feature_mapping column that points to id of feature_mapping_id column of the same table. I need to select root nodes that has children which satisfy various conditions. The conditions may extend to

Re: [GENERAL] Is EXISTS the most efficient approach for PostgreSql to check for existence of nodes in a tree?

On 05/17/2012 03:06 AM, Seref Arikan wrote: I have a key value table in my Postgresql db, which represents hierarchical data through parent_feature_mapping column that points to id of feature_mapping_id column of the same table. I need to select root nodes that has children which satisfy