perf(tables): run row count and page fetch concurrently in queryRows

Author: TheodoreSpeaks

apps/sim/lib/table/__tests__/table-wrapper.test.ts

@@ -211,8 +211,13 @@ describe('table-wrapper', () => {
       expect(dbChainMockFns.from).toHaveBeenCalledTimes(2)
     })
 
-    it('computes totalCount when includeTotal=true', async () => {
-      dbChainMockFns.where.mockResolvedValueOnce([{ count: 7 }])
+    it('computes totalCount concurrently when includeTotal=true', async () => {
+      // The main query's `.where()` is built first (call #1), then the count
+      // query's `.where()` (call #2) — both issued together via Promise.all.
+      const defaultWhere = dbChainMockFns.where.getMockImplementation()!
+      dbChainMockFns.where
+        .mockImplementationOnce(defaultWhere)
+        .mockResolvedValueOnce([{ count: 7 }])
       stubRowFetch([])
       const result = await queryRows(TABLE, { includeTotal: true, withExecutions: false })
       expect(result.totalCount).toBe(7)

apps/sim/lib/table/table-wrapper.ts

@@ -117,15 +117,6 @@ export async function queryRows(
     }
   }
 
-  let totalCount: number | null = null
-  if (includeTotal) {
-    const countResult = await db
-      .select({ count: count() })
-      .from(userTableRows)
-      .where(whereClause ?? baseConditions)
-    totalCount = Number(countResult[0].count)
-  }
-
   let orderByClause
   if (sort && Object.keys(sort).length > 0) {
     orderByClause = buildSortClause(sort, tableName, columns)
@@ -142,7 +133,18 @@ export async function queryRows(
     query = query.orderBy(userTableRows.position) as typeof query
   }
 
-  const rows = await query.limit(limit).offset(offset)
+  // Count and page fetch are independent reads — run them concurrently so the
+  // `includeTotal` hot path doesn't pay two serial round-trips.
+  const rowsPromise = query.limit(limit).offset(offset)
+  const countPromise = includeTotal
+    ? db
+        .select({ count: count() })
+        .from(userTableRows)
+        .where(whereClause ?? baseConditions)
+    : null
+
+  const [rows, countResult] = await Promise.all([rowsPromise, countPromise])
+  const totalCount = countResult ? Number(countResult[0].count) : null
 
   const executionsByRow = withExecutions
     ? await loadExecutionsByRow(