#19 mermaid diagrams from pg_catalog

mermaid_diagrams/dependent_relations.sql

@@ -0,0 +1,24 @@
+--DROP VIEW gwolofs.dependent_relations;
+
+CREATE OR REPLACE VIEW gwolofs.dependent_relations AS (
+    SELECT DISTINCT
+        rwr_cl.oid AS dep_oid,
+        ref_nsp.nspname AS ref_schema,
+        ref_cl.relname AS ref_name,
+        rwr_cl.relkind AS dep_type,
+        rwr_nsp.nspname AS dep_schema,
+        rwr_cl.relname AS dep_name,
+        ref_nsp.nspname || '.' || ref_cl.relname ||
+        --longer lines for inter-schema dependencies
+        CASE WHEN ref_nsp.nspname != rwr_nsp.nspname THEN ' ----> ' ELSE ' --> ' END
+        || rwr_nsp.nspname || '.' || rwr_cl.relname AS mermaid_relation
+    FROM pg_depend AS dep
+    JOIN pg_class AS ref_cl ON dep.refobjid = ref_cl.oid
+    JOIN pg_namespace AS ref_nsp ON ref_cl.relnamespace = ref_nsp.oid
+    JOIN pg_rewrite AS rwr ON dep.objid = rwr.oid
+    JOIN pg_class AS rwr_cl ON rwr.ev_class = rwr_cl.oid
+    JOIN pg_namespace AS rwr_nsp ON rwr_cl.relnamespace = rwr_nsp.oid
+    WHERE
+        dep.deptype = 'n'
+        AND dep.classid = 'pg_rewrite'::regclass
+);

mermaid_diagrams/get_recursive_dependencies.sql

@@ -0,0 +1,53 @@
+-- DROP FUNCTION gwolofs.get_recursive_dependencies(text, text);
+
+CREATE OR REPLACE FUNCTION gwolofs.get_recursive_dependencies (
+    sch_name text,
+    obj_name text
+) RETURNS TABLE(oid oid, obj_schema character varying, obj_name character varying, obj_type character varying) 
+    LANGUAGE sql
+    COST 100
+    VOLATILE PARALLEL UNSAFE
+    ROWS 1000
+AS $BODY$
+
+    SELECT oid, obj_schema, obj_name, obj_type
+        FROM (
+            WITH RECURSIVE recursive_deps(oid, obj_schema, obj_name, obj_type, depth) AS
+            (
+                SELECT
+                    0::oid,
+                    get_recursive_dependencies.sch_name::character varying COLLATE "C",
+                    get_recursive_dependencies.obj_name::character varying COLLATE "C",
+                    null::varchar,
+                    0
+                UNION
+                SELECT
+                    deps.dep_oid,
+                    deps.dep_schema::varchar,
+                    deps.dep_name::varchar,
+                    deps.dep_type::varchar,
+                    recursive_deps.depth + 1
+                FROM
+                    (
+                        SELECT dep_oid, ref_schema, ref_name, dep_type, dep_schema, dep_name
+                        FROM gwolofs.dependent_relations
+                    ) AS deps
+                JOIN recursive_deps ON
+                    deps.ref_schema = recursive_deps.obj_schema
+                    AND deps.ref_name = recursive_deps.obj_name
+                WHERE
+                    depth < 20
+                    AND NOT (
+                        deps.ref_schema = deps.dep_schema
+                        AND deps.ref_name = deps.dep_name
+                    )
+            )
+
+            SELECT oid, obj_schema, obj_name, obj_type, depth
+            FROM recursive_deps
+            WHERE depth >= 0
+        ) AS t
+        GROUP BY t.oid, t.obj_schema, t.obj_name, t.obj_type
+        ORDER BY max(depth) DESC
+
+$BODY$;

mermaid_diagrams/mermaid_dependency_diagram.sql

@@ -0,0 +1,84 @@
+--DROP FUNCTION gwolofs.mermaid_dependency_diagram(text, text);
+
+CREATE OR REPLACE FUNCTION gwolofs.mermaid_dependency_diagram (
+    sch_name text,
+    obj_name text
+) RETURNS TEXT
+    LANGUAGE sql
+    COST 100
+    VOLATILE PARALLEL UNSAFE
+AS $BODY$
+
+    WITH dependencies AS (
+        --every object that has a relationship with some object in the recursive dependency tree (2nd level dependencies)
+        SELECT dep_schema, dep_name, ref_schema, ref_name
+        FROM gwolofs.dependent_relations AS deps
+        WHERE
+            dep_schema || '.' || dep_name IN (
+                SELECT obj_schema || '.' || obj_name FROM gwolofs.get_recursive_dependencies(
+                    mermaid_dependency_diagram.sch_name,
+                    mermaid_dependency_diagram.obj_name
+                )
+            )
+            OR ref_schema || '.' || ref_name IN (
+                SELECT obj_schema || '.' || obj_name FROM gwolofs.get_recursive_dependencies(
+                    mermaid_dependency_diagram.sch_name,
+                    mermaid_dependency_diagram.obj_name
+                )
+            )
+    )
+
+    --aggregate subgraphs and relationships into a complete diagram
+    SELECT
+    '%%{init: {''theme'': ''neutral'', ''flowchart'': {''defaultRenderer'': ''elk''}}}%%' || chr(10) ||
+    'flowchart TD' || chr(10) ||
+    string_agg('    ' || mermaid_object, chr(10)) AS mermaid_diagram
+    FROM (
+        --subgraphs for each schema
+        SELECT
+            'subgraph ' || obj_schema || chr(10) ||
+            --more work needed to give different shapes to different objects.
+            string_agg('        ' || 
+                --CASE obj_type
+                --    WHEN 'v' THEN lat.full_name || '{{' || lat.full_name || '}}'
+                --    WHEN 'm' THEN lat.full_name || '[[' || lat.full_name || ']]'
+                --    ELSE lat.full_name
+                --END,
+                objs.full_name || '[' || objs.obj_name || ']', chr(10)
+            ) || chr(10) || '    end' AS mermaid_object
+        FROM (
+            SELECT DISTINCT
+                dep_schema AS obj_schema,
+                dep_schema || '.' || dep_name AS full_name,
+                dep_name AS obj_name
+            FROM dependencies
+            UNION
+            SELECT DISTINCT
+                ref_schema AS obj_schema,
+                ref_schema || '.' || ref_name  AS full_name,
+                ref_name AS obj_name
+            FROM dependencies
+        ) AS objs
+        GROUP BY obj_schema
+        UNION ALL
+        --relationships between nodes
+        SELECT mermaid_relation
+        FROM gwolofs.dependent_relations AS deps
+        WHERE dep_schema || '.' || dep_name IN (
+            SELECT obj_schema || '.' || obj_name
+            FROM gwolofs.get_recursive_dependencies(
+                    mermaid_dependency_diagram.sch_name,
+                    mermaid_dependency_diagram.obj_name
+                )
+        ) AND NOT (
+            deps.ref_schema = deps.dep_schema
+            AND deps.ref_name = deps.dep_name
+        )
+        UNION ALL
+        SELECT '    style '
+            || mermaid_dependency_diagram.sch_name || '.'
+            || mermaid_dependency_diagram.obj_name
+            || ' fill:#f9f,stroke:#333,stroke-width:4px,color:black'
+    ) AS objects
+
+$BODY$;

mermaid_diagrams/mermaid_dependency_diagram_simple.sql

@@ -0,0 +1,84 @@
+--DROP FUNCTION gwolofs.mermaid_dependency_diagram_simple(text, text);
+
+CREATE OR REPLACE FUNCTION gwolofs.mermaid_dependency_diagram_simple (
+    sch_name text,
+    obj_name text
+) RETURNS TEXT
+    LANGUAGE sql
+    COST 100
+    VOLATILE PARALLEL UNSAFE
+AS $BODY$
+
+    WITH dependencies AS (
+        --every object that has a relationship with some object in the recursive dependency tree (2nd level dependencies)
+        SELECT dep_schema, dep_name, ref_schema, ref_name
+        FROM gwolofs.dependent_relations AS deps
+        WHERE
+            dep_schema || '.' || dep_name IN (
+                SELECT obj_schema || '.' || obj_name FROM gwolofs.get_recursive_dependencies(
+                    mermaid_dependency_diagram_simple.sch_name,
+                    mermaid_dependency_diagram_simple.obj_name
+                )
+            )
+            AND ref_schema || '.' || ref_name IN (
+                SELECT obj_schema || '.' || obj_name FROM gwolofs.get_recursive_dependencies(
+                    mermaid_dependency_diagram_simple.sch_name,
+                    mermaid_dependency_diagram_simple.obj_name
+                )
+            )
+    )
+
+    --aggregate subgraphs and relationships into a complete diagram
+    SELECT
+    '%%{init: {''theme'': ''neutral'', ''flowchart'': {''defaultRenderer'': ''elk''}}}%%' || chr(10) ||
+    'flowchart TD' || chr(10) ||
+    string_agg('    ' || mermaid_object, chr(10)) AS mermaid_diagram
+    FROM (
+        --subgraphs for each schema
+        SELECT
+            'subgraph ' || obj_schema || chr(10) ||
+            --more work needed to give different shapes to different objects.
+            string_agg('        ' || 
+                --CASE obj_type
+                --    WHEN 'v' THEN lat.full_name || '{{' || lat.full_name || '}}'
+                --    WHEN 'm' THEN lat.full_name || '[[' || lat.full_name || ']]'
+                --    ELSE lat.full_name
+                --END,
+                objs.full_name || '[[' || objs.full_name || ']]', chr(10)
+            ) || chr(10) || '    end' AS mermaid_object
+        FROM (
+            SELECT DISTINCT dep_schema AS obj_schema, dep_schema || '.' || dep_name AS full_name
+            FROM dependencies
+            UNION
+            SELECT DISTINCT ref_schema AS obj_schema, ref_schema || '.' || ref_name  AS full_name
+            FROM dependencies
+        ) AS objs
+        GROUP BY obj_schema
+        UNION ALL
+        --relationships between nodes
+        SELECT mermaid_relation
+        FROM gwolofs.dependent_relations AS deps
+        WHERE ref_schema || '.' || ref_name IN (
+            SELECT obj_schema || '.' || obj_name
+            FROM gwolofs.get_recursive_dependencies(
+                    mermaid_dependency_diagram_simple.sch_name,
+                    mermaid_dependency_diagram_simple.obj_name
+                )
+        ) AND dep_schema || '.' || dep_name IN (
+            SELECT obj_schema || '.' || obj_name
+            FROM gwolofs.get_recursive_dependencies(
+                    mermaid_dependency_diagram_simple.sch_name,
+                    mermaid_dependency_diagram_simple.obj_name
+                )
+        ) AND NOT (
+            deps.ref_schema = deps.dep_schema
+            AND deps.ref_name = deps.dep_name
+        )
+        UNION ALL
+        SELECT '    style '
+            || mermaid_dependency_diagram_simple.sch_name || '.'
+            || mermaid_dependency_diagram_simple.obj_name
+            || ' fill:#f9f,stroke:#333,stroke-width:4px'
+    ) AS objects
+
+$BODY$;