fix: preserve typmod for extension types in column type resolution (#295)

ir/queries/queries.sql

@@ -88,10 +88,13 @@ WITH column_base AS (
                 END
             WHEN dt.typtype = 'b' THEN
                 -- Non-array base types: qualify if not in pg_catalog or table's schema
+                -- Use format_type to preserve typmod for extension types (e.g., vector(384) for pgvector)
                 CASE
                     WHEN dn.nspname = 'pg_catalog' THEN c.udt_name
-                    WHEN dn.nspname = c.table_schema THEN dt.typname
-                    ELSE dn.nspname || '.' || dt.typname
+                    WHEN dn.nspname = c.table_schema THEN
+                        dt.typname || COALESCE(substring(format_type(a.atttypid, a.atttypmod) FROM '\([^)]*\)'), '')
+                    ELSE
+                        dn.nspname || '.' || dt.typname || COALESCE(substring(format_type(a.atttypid, a.atttypmod) FROM '\([^)]*\)'), '')
                 END
             ELSE c.udt_name
         END AS resolved_type,
@@ -201,10 +204,13 @@ WITH column_base AS (
                 END
             WHEN dt.typtype = 'b' THEN
                 -- Non-array base types: qualify if not in pg_catalog or table's schema
+                -- Use format_type to preserve typmod for extension types (e.g., vector(384) for pgvector)
                 CASE
                     WHEN dn.nspname = 'pg_catalog' THEN c.udt_name
-                    WHEN dn.nspname = c.table_schema THEN dt.typname
-                    ELSE dn.nspname || '.' || dt.typname
+                    WHEN dn.nspname = c.table_schema THEN
+                        dt.typname || COALESCE(substring(format_type(a.atttypid, a.atttypmod) FROM '\([^)]*\)'), '')
+                    ELSE
+                        dn.nspname || '.' || dt.typname || COALESCE(substring(format_type(a.atttypid, a.atttypmod) FROM '\([^)]*\)'), '')
                 END
             ELSE c.udt_name
         END AS resolved_type,

testdata/diff/create_table/issue_295_pgvector_typmod/diff.sql

@@ -0,0 +1,2 @@
+ALTER TABLE activity ADD COLUMN embedding halfvec(384);
+CREATE INDEX IF NOT EXISTS activity_embedding_idx ON activity USING hnsw (embedding halfvec_cosine_ops);

testdata/diff/create_table/issue_295_pgvector_typmod/new.sql

@@ -0,0 +1,9 @@
+-- Desired state: add pgvector columns with dimensions (typmod)
+-- Reproduces GitHub issue #295 where vector(384)/halfvec(384) dimensions were dropped
+CREATE TABLE public.activity (
+    id bigserial PRIMARY KEY,
+    embedding halfvec(384)
+);
+
+CREATE INDEX activity_embedding_idx
+    ON activity USING hnsw (embedding halfvec_cosine_ops);

testdata/diff/create_table/issue_295_pgvector_typmod/old.sql

@@ -0,0 +1,4 @@
+-- Initial state: table without vector columns
+CREATE TABLE public.activity (
+    id bigserial PRIMARY KEY
+);

testdata/diff/create_table/issue_295_pgvector_typmod/plan.json

@@ -0,0 +1,44 @@
+{
+  "version": "1.0.0",
+  "pgschema_version": "1.7.1",
+  "created_at": "1970-01-01T00:00:00Z",
+  "source_fingerprint": {
+    "hash": "0000000000000000000000000000000000000000000000000000000000000000"
+  },
+  "groups": [
+    {
+      "steps": [
+        {
+          "sql": "ALTER TABLE activity ADD COLUMN embedding halfvec(384);",
+          "type": "table.column",
+          "operation": "create",
+          "path": "public.activity.embedding"
+        }
+      ]
+    },
+    {
+      "steps": [
+        {
+          "sql": "CREATE INDEX CONCURRENTLY IF NOT EXISTS activity_embedding_idx ON activity USING hnsw (embedding halfvec_cosine_ops);",
+          "type": "table.index",
+          "operation": "create",
+          "path": "public.activity.activity_embedding_idx"
+        }
+      ]
+    },
+    {
+      "steps": [
+        {
+          "sql": "SELECT \n    COALESCE(i.indisvalid, false) as done,\n    CASE \n        WHEN p.blocks_total > 0 THEN p.blocks_done * 100 / p.blocks_total\n        ELSE 0\n    END as progress\nFROM pg_class c\nLEFT JOIN pg_index i ON c.oid = i.indexrelid\nLEFT JOIN pg_stat_progress_create_index p ON c.oid = p.index_relid\nWHERE c.relname = 'activity_embedding_idx';",
+          "directive": {
+            "type": "wait",
+            "message": "Creating index activity_embedding_idx"
+          },
+          "type": "table.index",
+          "operation": "create",
+          "path": "public.activity.activity_embedding_idx"
+        }
+      ]
+    }
+  ]
+}

testdata/diff/create_table/issue_295_pgvector_typmod/plan.sql

@@ -0,0 +1,15 @@
+ALTER TABLE activity ADD COLUMN embedding halfvec(384);
+
+CREATE INDEX CONCURRENTLY IF NOT EXISTS activity_embedding_idx ON activity USING hnsw (embedding halfvec_cosine_ops);
+
+-- pgschema:wait
+SELECT
+    COALESCE(i.indisvalid, false) as done,
+    CASE
+        WHEN p.blocks_total > 0 THEN p.blocks_done * 100 / p.blocks_total
+        ELSE 0
+    END as progress
+FROM pg_class c
+LEFT JOIN pg_index i ON c.oid = i.indexrelid
+LEFT JOIN pg_stat_progress_create_index p ON c.oid = p.index_relid
+WHERE c.relname = 'activity_embedding_idx';

testdata/diff/create_table/issue_295_pgvector_typmod/plan.txt

@@ -0,0 +1,28 @@
+Plan: 1 to modify.
+
+Summary by type:
+  tables: 1 to modify
+
+Tables:
+  ~ activity
+    + embedding (column)
+    + activity_embedding_idx (index)
+
+DDL to be executed:
+--------------------------------------------------
+
+ALTER TABLE activity ADD COLUMN embedding halfvec(384);
+
+CREATE INDEX CONCURRENTLY IF NOT EXISTS activity_embedding_idx ON activity USING hnsw (embedding halfvec_cosine_ops);
+
+-- pgschema:wait
+SELECT
+    COALESCE(i.indisvalid, false) as done,
+    CASE
+        WHEN p.blocks_total > 0 THEN p.blocks_done * 100 / p.blocks_total
+        ELSE 0
+    END as progress
+FROM pg_class c
+LEFT JOIN pg_index i ON c.oid = i.indexrelid
+LEFT JOIN pg_stat_progress_create_index p ON c.oid = p.index_relid
+WHERE c.relname = 'activity_embedding_idx';

testdata/diff/create_table/issue_295_pgvector_typmod/setup.sql

@@ -0,0 +1,4 @@
+-- Setup: Requires pgvector extension
+-- This test is skipped in CI (embedded-postgres doesn't include pgvector).
+-- To run manually, install pgvector and remove from skipListRequiresExtension.
+CREATE EXTENSION IF NOT EXISTS vector;

testutil/skip_list.go

@@ -51,6 +51,14 @@ var skipListPG14_15 = []string{
 	"TestIncludeIntegration",
 }
 
+// skipListRequiresExtension defines test cases that require third-party extensions
+// not available in embedded-postgres (e.g., pgvector, PostGIS).
+// These tests are skipped on all PostgreSQL versions in CI but can be run manually
+// against a database with the required extensions installed.
+var skipListRequiresExtension = []string{
+	"create_table/issue_295_pgvector_typmod",
+}
+
 // skipListForVersion maps PostgreSQL major versions to their skip lists.
 var skipListForVersion = map[int][]string{
 	14: skipListPG14_15,
@@ -70,6 +78,14 @@ var skipListForVersion = map[int][]string{
 func ShouldSkipTest(t *testing.T, testName string, majorVersion int) {
 	t.Helper()
 
+	// Check extension-required skip list (applies to all versions)
+	for _, pattern := range skipListRequiresExtension {
+		patternNormalized := strings.ReplaceAll(pattern, "/", "_")
+		if testName == patternNormalized || testName == pattern {
+			t.Skipf("Skipping test %q: requires third-party extension not available in embedded-postgres", testName)
+		}
+	}
+
 	// Get skip patterns for this version
 	skipPatterns, exists := skipListForVersion[majorVersion]
 	if !exists {