ZhengZhanFei opened a new issue, #2322:
URL: https://github.com/apache/age/issues/2322
On page 17.7, for age1.6, when I was using it, I first created a Gin index,
and then inserted data in batches. However, the data could not be retrieved.
CREATE EXTENSION IF NOT EXISTS age;
SET search_path = ag_catalog, "$user", PUBLIC;
SELECT create_graph('graph_name');
SELECT create_vlabel('graph_name','n1');
create index idx_n1_properties_gin on graph_name."n1" using gin(properties)
-- There are 10 pieces of data in the CSV file.
SELECT load_labels_from_file(
'graph_name',
'n1',
'/tmp/age/age-node-10.csv'
);
-- Return 10
SELECT COUNT(*) FROM graph_name."n1";
-- Query Statement 1
-- {"id": 844424930131969, "label": "n1", "properties": {"id": "1",
"__id__": 1, "node_name": "type2_1", "node_type": "type2", "node_identify":
"1"}}::vertex
SELECT *
FROM cypher('graph_name', $$
MATCH (a:n1 {node_name: 'type2_1', node_type: 'type2'})
RETURN
a
$$) AS (
a agtype
);
<img width="1185" height="335" alt="Image"
src="https://github.com/user-attachments/assets/e5e9a4a4-8389-40b3-ae46-48ee627a7aed";
/>
-- Query Statement 2
SELECT *
FROM cypher('graph_name', $$
MATCH (a:n1 {node_name: 'type2_1'})
RETURN
a
$$) AS (
a agtype
);
<img width="1153" height="356" alt="Image"
src="https://github.com/user-attachments/assets/a3769294-b79c-4c0e-a790-f062173145db";
/>
During the first query, my conditions were 'node_name' and 'node_type', and
I was able to retrieve the records. However, during the second query, I removed
the 'node_type' condition from my criteria, but no results were returned. I
thought that the second query should also have returned results, but it didn't.
-- -- Query Statement 3
SELECT *
FROM cypher('graph_name', $$
MATCH (a:n1)
WHERE a.node_name = 'type2_1'
RETURN a
$$) AS (
a agtype
);
During the third query, I was able to retrieve the information by using the
"where" clause.
The execution plans corresponding to the three SQL statements are as
follows: when using the gin index, there will be a situation where the record
cannot be retrieved.
SELECT *
FROM cypher('graph_name', $$
explain MATCH (a:n1 {node_name: 'type2_1', node_type: 'type2'})
RETURN
a
$$) AS (
a agtype
);
Seq Scan on n1 a (cost=0.00..25.06 rows=12 width=32)
Filter: (properties @> '{"node_name": "type2_1", "node_type":
"type2"}'::agtype)
SELECT *
FROM cypher('graph_name', $$
explain MATCH (a:n1 {node_name: 'type2_1'})
RETURN
a
$$) AS (
a agtype
);
Bitmap Heap Scan on n1 a (cost=13.04..23.79 rows=12 width=32)
Recheck Cond: (properties @> '{"node_name": "type2_1"}'::agtype)
-> Bitmap Index Scan on idx_n1_properties_gin (cost=0.00..13.04 rows=12
width=0)
Index Cond: (properties @> '{"node_name": "type2_1"}'::agtype)
SELECT *
FROM cypher('graph_name', $$
explain MATCH (a:n1)
WHERE a.node_name = 'type2_1'
RETURN a
$$) AS (
a agtype
);
Seq Scan on n1 a (cost=0.00..28.03 rows=6 width=32)
Filter: (agtype_access_operator(VARIADIC ARRAY[properties,
'"node_name"'::agtype]) = '"type2_1"'::agtype)
My installation process:
sudo apt-get install build-essential libreadline-dev zlib1g-dev flex bison
sudo git clone https://github.com/apache/age.git
cd age
git config --global --add safe.directory /home/age
sudo git checkout PG17/v1.6.0-rc0
sudo make PG_CONFIG=/Programs/postgres17.7/bin/pg_config install
-- postgres version
select version()
PostgreSQL 17.7 on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu
9.4.0-1ubuntu1~20.04.2) 9.4.0, 64-bit
I have been struggling with this for a long time. I want to know where I
went wrong. Thank you for your help.
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