Read source columns from pg_catalog, not information_schema

information_schema.columns omits materialized views -- they are not in the
SQL standard -- and gs.osm_skinny is one. So the source this app runs on
looked like it had no columns at all: creating a version failed with "No
usable columns in col_meta" while col_meta plainly held thirty-six, and
registering such a source would have seeded nothing.

RELATION_COLUMNS_SQL returns the same shape information_schema did, so
mapType and every caller are unchanged: data_type is format_type with the
modifier stripped, which spells things the same way ('character varying',
'numeric'), and precision and scale are unpacked from atttypmod as
information_schema does internally. Verified against the live matview -- 36
usable columns, and the types map to exactly what fc_osm_skinny_29 already
has.

The table browser had the same blind spot from information_schema.tables and
now lists from pg_class by relkind, so a materialized view can be registered
rather than merely used by a source registered when it was still a table.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -353,6 +353,22 @@ effects call the API immediately.
 `pf_user: 'admin'`, which any client could have set to anything. The audit log
 now names the account that made the change.
 
+## Source columns come from pg_catalog
+
+`information_schema.columns` omits **materialized views** — they are not in the
+SQL standard — and `gs.osm_skinny` is one. So the source the whole app is built
+on looked like it had no columns: registering it seeded nothing, and creating a
+version failed with "No usable columns in col_meta" while col_meta plainly held
+thirty-six.
+
+`RELATION_COLUMNS_SQL` in `lib/utils.js` is the replacement, used by version
+creation, source registration and the table preview. It returns the same shape
+information_schema did, so `mapType` and the callers were unchanged:
+`data_type` is `format_type` with the modifier stripped, which gives the same
+spelling (`character varying`, `numeric`), and precision and scale are unpacked
+from `atttypmod`. The table browser lists from `pg_class` by `relkind` for the
+same reason.
+
 ## Territory scoping
 
 An account sees and changes only its own territory. The list lives on

lib/utils.js

@@ -3,7 +3,41 @@ function fcTable(tname, versionId) {
     return `pf.fc_${tname}_${versionId}`;
 }
 
-// map information_schema data_type to a clean postgres column type
+// The columns of a relation, from pg_catalog rather than information_schema.
+//
+// information_schema.columns omits materialized views -- they are not in the
+// SQL standard -- so a source built on one looked like it had no columns at
+// all: registering it seeded nothing, and creating a version failed with "No
+// usable columns in col_meta" while col_meta plainly had thirty-six.
+//
+// The shape matches what information_schema returned, so mapType and the
+// callers did not have to change. data_type is format_type with the modifier
+// stripped, which gives the same spelling information_schema uses ('character
+// varying', 'numeric'), and the numeric precision and scale are unpacked from
+// atttypmod the way information_schema does internally.
+//
+// Takes $1 = schema, $2 = relation name.
+const RELATION_COLUMNS_SQL = `
+    SELECT a.attname                                              AS column_name
+          ,regexp_replace(format_type(a.atttypid, a.atttypmod), '\\(.*\\)$', '') AS data_type
+          ,a.attnum                                               AS ordinal_position
+          ,CASE WHEN a.attnotnull THEN 'NO' ELSE 'YES' END        AS is_nullable
+          ,CASE WHEN a.atttypid = 'numeric'::regtype AND a.atttypmod > 4
+                THEN ((a.atttypmod - 4) >> 16) & 65535 END        AS numeric_precision
+          ,CASE WHEN a.atttypid = 'numeric'::regtype AND a.atttypmod > 4
+                THEN (a.atttypmod - 4) & 65535 END                AS numeric_scale
+    FROM pg_attribute a
+    JOIN pg_class     c ON c.oid = a.attrelid
+    JOIN pg_namespace n ON n.oid = c.relnamespace
+    WHERE TRUE
+      AND n.nspname = $1
+      AND c.relname = $2
+      AND c.relkind IN ('r', 'v', 'm', 'f', 'p')
+      AND a.attnum > 0
+      AND NOT a.attisdropped
+`;
+
+// map a data_type name to a clean postgres column type
 function mapType(dataType, numericPrecision, numericScale) {
     switch (dataType) {
         case 'character varying':
@@ -36,4 +70,4 @@ function mapType(dataType, numericPrecision, numericScale) {
     }
 }
 
-module.exports = { fcTable, mapType };
+module.exports = { fcTable, mapType, RELATION_COLUMNS_SQL };

routes/sources.js

@@ -1,5 +1,6 @@
 const express = require('express');
 const { generateSQL, buildTerritoryClause } = require('../lib/sql_generator');
+const { RELATION_COLUMNS_SQL } = require('../lib/utils');
 const { sessionTerritory } = require('../lib/auth');
 const { sessionUser } = require('../lib/auth');
 
@@ -42,15 +43,14 @@ module.exports = function(pool) {
             );
             const source = src.rows[0];
 
-            // seed col_meta from information_schema
+            // seed col_meta from the source's real columns
             await client.query(`
                 INSERT INTO pf.col_meta (source_id, cname, role, opos)
-                SELECT $1, column_name, 'dimension', ordinal_position
+                SELECT $3, column_name, 'dimension', ordinal_position
-                FROM information_schema.columns
+                FROM (${RELATION_COLUMNS_SQL}) c
-                WHERE table_schema = $2 AND table_name = $3
                 ORDER BY ordinal_position
                 ON CONFLICT (source_id, cname) DO NOTHING
-            `, [source.id, schema, tname]);
+            `, [schema, tname, source.id]);
 
             await client.query('COMMIT');
             res.status(201).json(source);

routes/tables.js

@@ -1,4 +1,5 @@
 const express = require('express');
+const { RELATION_COLUMNS_SQL } = require('../lib/utils');
 
 module.exports = function(pool) {
     const router = express.Router();
@@ -7,15 +8,18 @@ module.exports = function(pool) {
     router.get('/tables', async (req, res) => {
         try {
             const result = await pool.query(`
+                -- pg_class, not information_schema.tables, which omits
+                -- materialized views: gs.osm_skinny is one, and the browser
+                -- could not offer what the app is already built on.
                 SELECT
-                    t.table_schema  AS schema,
+                    n.nspname           AS schema,
-                    t.table_name    AS tname,
+                    c.relname           AS tname,
                     c.reltuples::bigint AS row_estimate
-                FROM information_schema.tables t
+                FROM pg_class c
-                LEFT JOIN pg_namespace n ON n.nspname = t.table_schema
+                JOIN pg_namespace n ON n.oid = c.relnamespace
-                LEFT JOIN pg_class c ON c.relname = t.table_name AND c.relnamespace = n.oid
+                WHERE c.relkind IN ('r', 'v', 'm', 'f', 'p')
-                WHERE t.table_schema NOT IN ('pg_catalog', 'information_schema', 'pf')
+                  AND n.nspname NOT IN ('pg_catalog', 'information_schema', 'pf')
-                ORDER BY t.table_schema, t.table_name
+                ORDER BY n.nspname, c.relname
             `);
             res.json(result.rows);
         } catch (err) {
@@ -31,12 +35,8 @@ module.exports = function(pool) {
             return res.status(400).json({ error: 'Invalid schema or table name' });
         }
         try {
-            const cols = await pool.query(`
+            const cols = await pool.query(
-                SELECT column_name, data_type, is_nullable, ordinal_position
+                `${RELATION_COLUMNS_SQL} ORDER BY ordinal_position`, [schema, tname]);
-                FROM information_schema.columns
-                WHERE table_schema = $1 AND table_name = $2
-                ORDER BY ordinal_position
-            `, [schema, tname]);
 
             const rows = await pool.query(
                 `SELECT * FROM ${schema}.${tname} LIMIT 5`

routes/versions.js

@@ -1,5 +1,5 @@
 const express = require('express');
-const { fcTable, mapType } = require('../lib/utils');
+const { fcTable, mapType, RELATION_COLUMNS_SQL } = require('../lib/utils');
 const { sessionUser, sessionTerritory } = require('../lib/auth');
 const { buildTerritoryClause } = require('../lib/sql_generator');
 
@@ -39,8 +39,9 @@ module.exports = function(pool) {
             }
             const source = srcResult.rows[0];
 
-            // fetch col_meta joined to information_schema for data types
+            // col_meta joined to the source's real columns, for the data types
             const colResult = await client.query(`
+                WITH cols AS (${RELATION_COLUMNS_SQL})
                 SELECT
                     m.cname,
                     m.role,
@@ -49,14 +50,11 @@ module.exports = function(pool) {
                     i.numeric_precision,
                     i.numeric_scale
                 FROM pf.col_meta m
-                JOIN information_schema.columns i
+                JOIN cols i ON i.column_name = m.cname
-                    ON  i.table_schema = $2
+                WHERE m.source_id = $3
-                    AND i.table_name   = $3
-                    AND i.column_name  = m.cname
-                WHERE m.source_id = $1
                   AND m.role NOT IN ('ignore')
                 ORDER BY m.opos
-            `, [sourceId, source.schema, source.tname]);
+            `, [source.schema, source.tname, sourceId]);
 
             if (colResult.rows.length === 0) {
                 return res.status(400).json({