Github user jingyimei commented on a diff in the pull request:
https://github.com/apache/madlib/pull/244#discussion_r177892625
--- Diff: src/ports/postgres/modules/graph/pagerank.py_in ---
@@ -44,29 +44,62 @@ from utilities.utilities import add_postfix
from utilities.utilities import extract_keyvalue_params
from utilities.utilities import unique_string, split_quoted_delimited_str
from utilities.utilities import is_platform_pg
+from utilities.utilities import py_list_to_sql_string
from utilities.validate_args import columns_exist_in_table,
get_cols_and_types
from utilities.validate_args import table_exists
+
def validate_pagerank_args(schema_madlib, vertex_table, vertex_id,
edge_table,
edge_params, out_table, damping_factor,
max_iter,
- threshold, grouping_cols_list):
+ threshold, grouping_cols_list,
nodes_of_interest):
"""
Function to validate input parameters for PageRank
"""
validate_graph_coding(vertex_table, vertex_id, edge_table, edge_params,
out_table, 'PageRank')
- ## Validate args such as threshold and max_iter
+ # Validate args such as threshold and max_iter
validate_params_for_link_analysis(schema_madlib, "PageRank",
- threshold, max_iter,
- edge_table, grouping_cols_list)
+ threshold, max_iter,
+ edge_table, grouping_cols_list)
_assert(damping_factor >= 0.0 and damping_factor <= 1.0,
"PageRank: Invalid damping factor value ({0}), must be between
0 and 1.".
format(damping_factor))
-
-def pagerank(schema_madlib, vertex_table, vertex_id, edge_table, edge_args,
- out_table, damping_factor, max_iter, threshold,
grouping_cols, **kwargs):
+ # Validate against the givin set of nodes for Personalized Page Rank
+ if nodes_of_interest:
+ nodes_of_interest_count = len(nodes_of_interest)
+ vertices_count = plpy.execute("""
+ SELECT count(DISTINCT({vertex_id})) AS cnt FROM
{vertex_table}
+ WHERE {vertex_id} = ANY(ARRAY{nodes_of_interest})
+ """.format(**locals()))[0]["cnt"]
+ # Check to see if the given set of nodes exist in vertex table
+ if vertices_count != len(nodes_of_interest):
+ plpy.error("PageRank: Invalid value for {0}, must be a subset
of the vertex_table".format(
+ nodes_of_interest))
+ # Validate given set of nodes against each user group.
+ # If all the given nodes are not present in the user group
+ # then throw an error.
+ if grouping_cols_list:
+ missing_user_grps = ''
+ grp_by_column = get_table_qualified_col_str(
+ edge_table, grouping_cols_list)
+ grps_without_nodes = plpy.execute("""
+ SELECT {grp_by_column} FROM {edge_table}
+ WHERE src = ANY(ARRAY{nodes_of_interest}) group by
{grp_by_column}
+ having count(DISTINCT(src)) != {nodes_of_interest_count}
+ """.format(**locals()))
+ for row in range(grps_without_nodes.nrows()):
+ missing_user_grps +=
str(grps_without_nodes[row]['user_id'])
+ if row < grps_without_nodes.nrows() - 1:
+ missing_user_grps += ' ,'
+ if grps_without_nodes.nrows() > 0:
+ plpy.error("Nodes for Personalizaed Page Rank are missing
from these groups: {0} ".format(
+ missing_user_grps))
+
--- End diff --
Here some similar things are test twice - when `if nodes_of_interest`,
there is a `count` operation in line 73 and in line 77 there is one test(this
is for without grouping). Then when `if grouping_cols_list`, another `count`
and `compare` happen in line 90 per group. There might be a way to simplify the
logic here so that for grouping, we don't need to do it twice. Besides, if the
above query really slow down performance a lot, I would think about doing it
simpler by not giving a list of groups missing special nodes but just a
warning(optional, depending on how expensive the above query is).
---
