diff --git a/src/window.zig b/src/window.zig
index 1658a96..aeba2e8 100644
--- a/src/window.zig
+++ b/src/window.zig
@@ -1295,3 +1295,153 @@ test "running min and max over a text field, independently duped per row" {
     }
     const order = [_]querymod.OrderBy{.{ .field = "seq" }};
 
+    const mins = try compute(allocator, rows.items, &.{}, &order, .{ .field = "name", .kind = .min }, .rows);
+    defer freeResults(allocator, mins);
+    try std.testing.expectEqualStrings("mango", mins[0].text);
+    try std.testing.expectEqualStrings("apple", mins[1].text);
+    try std.testing.expectEqualStrings("apple", mins[2].text);
+
+    const maxs = try compute(allocator, rows.items, &.{}, &order, .{ .field = "name", .kind = .max }, .rows);
+    defer freeResults(allocator, maxs);
+    try std.testing.expectEqualStrings("mango", maxs[0].text);
+    try std.testing.expectEqualStrings("mango", maxs[1].text);
+    try std.testing.expectEqualStrings("mango", maxs[2].text);
+}
+
+test "sum/avg/min/max require a field, ranking family and COUNT(*) do not" {
+    const allocator = std.testing.allocator;
+    var rows = try threeRowsOnePartition(allocator);
+    defer {
+        for (rows.items) |*r| r.deinit();
+        rows.deinit();
+    }
+
+    try std.testing.expectError(error.MissingField, compute(allocator, rows.items, &.{}, &.{}, .{ .field = "", .kind = .sum }, .rows));
+    try std.testing.expectError(error.MissingField, compute(allocator, rows.items, &.{}, &.{}, .{ .field = "", .kind = .avg }, .rows));
+    try std.testing.expectError(error.MissingField, compute(allocator, rows.items, &.{}, &.{}, .{ .field = "", .kind = .min }, .rows));
+    try std.testing.expectError(error.MissingField, compute(allocator, rows.items, &.{}, &.{}, .{ .field = "", .kind = .max }, .rows));
+
+    const stars = try compute(allocator, rows.items, &.{}, &.{}, .{ .field = "", .kind = .count }, .rows);
+    defer freeResults(allocator, stars);
+    const nums = try compute(allocator, rows.items, &.{}, &.{}, .{ .field = "", .kind = .row_number }, .rows);
+    defer freeResults(allocator, nums);
+}
+
+test "sum on a non-numeric field is NonNumericField, integer overflow is Overflow" {
+    const allocator = std.testing.allocator;
+    var rows = std.ArrayList(Row).init(allocator);
+    defer {
+        for (rows.items) |*r| r.deinit();
+        rows.deinit();
+    }
+    try rows.append(try makeRow(allocator, &.{.{ .name = "x", .value = .{ .text = "nope" } }}));
+    try std.testing.expectError(error.NonNumericField, compute(allocator, rows.items, &.{}, &.{}, .{ .field = "x", .kind = .sum }, .rows));
+
+    var overflowRows = std.ArrayList(Row).init(allocator);
+    defer {
+        for (overflowRows.items) |*r| r.deinit();
+        overflowRows.deinit();
+    }
+    try overflowRows.append(try makeRow(allocator, &.{.{ .name = "x", .value = .{ .int = std.math.maxInt(i64) } }}));
+    try overflowRows.append(try makeRow(allocator, &.{.{ .name = "x", .value = .{ .int = 1 } }}));
+    try std.testing.expectError(error.Overflow, compute(allocator, overflowRows.items, &.{}, &.{}, .{ .field = "x", .kind = .sum }, .rows));
+}
+
+test "compute on zero rows returns an empty result, no crash" {
+    const allocator = std.testing.allocator;
+    const rows = [_]Row{};
+    const results = try compute(allocator, &rows, &.{}, &.{}, .{ .field = "", .kind = .row_number }, .rows);
+    defer freeResults(allocator, results);
+    try std.testing.expectEqual(@as(usize, 0), results.len);
+}
+
+test "specLabel matches aggregate.zig's kind_field / bare-kind convention" {
+    const allocator = std.testing.allocator;
+    const bare = try specLabel(allocator, .{ .field = "", .kind = .row_number });
+    defer allocator.free(bare);
+    try std.testing.expectEqualStrings("row_number", bare);
+
+    const withField = try specLabel(allocator, .{ .field = "score", .kind = .sum });
+    defer allocator.free(withField);
+    try std.testing.expectEqualStrings("sum_score", withField);
+}
+
+test "compute propagates OutOfMemory without leaking, at an early allocation" {
+    const allocator = std.testing.allocator;
+    var rows = try threeRowsOnePartition(allocator);
+    defer {
+        for (rows.items) |*r| r.deinit();
+        rows.deinit();
+    }
+
+    var failing = std.testing.FailingAllocator.init(allocator, .{ .fail_index = 0 });
+    try std.testing.expectError(error.OutOfMemory, compute(failing.allocator(), rows.items, &.{}, &.{}, .{ .field = "score", .kind = .sum }, .rows));
+}
+
+test "compute propagates OutOfMemory without leaking, mid-way through partitioned min/max" {
+    const allocator = std.testing.allocator;
+    var rows = std.ArrayList(Row).init(allocator);
+    defer {
+        for (rows.items) |*r| r.deinit();
+        rows.deinit();
+    }
+    const names = [_][]const u8{ "mango", "apple", "kiwi", "banana", "fig" };
+    for (names) |n| {
+        try rows.append(try makeRow(allocator, &.{.{ .name = "name", .value = .{ .text = n } }}));
+    }
+
+    var failing = std.testing.FailingAllocator.init(allocator, .{ .fail_index = 4 });
+    try std.testing.expectError(error.OutOfMemory, compute(failing.allocator(), rows.items, &.{}, &.{}, .{ .field = "name", .kind = .min }, .rows));
+}
+
+test "orderedIndices flattens partitions in first-seen order, each sorted by orderBy" {
+    const allocator = std.testing.allocator;
+    var rows = std.ArrayList(Row).init(allocator);
+    defer {
+        for (rows.items) |*r| r.deinit();
+        rows.deinit();
+    }
+    // First-seen partition order: warsaw, krakow. Within each, sort by
+    // score ascending should reorder relative to input.
+    const data = [_]struct { city: []const u8, score: i64 }{
+        .{ .city = "warsaw", .score = 5 },
+        .{ .city = "krakow", .score = 9 },
+        .{ .city = "warsaw", .score = 1 },
+        .{ .city = "krakow", .score = 2 },
+    };
+    for (data) |d| {
+        try rows.append(try makeRow(allocator, &.{
+            .{ .name = "city", .value = .{ .text = d.city } },
+            .{ .name = "score", .value = .{ .int = d.score } },
+        }));
+    }
+
+    const partition = [_][]const u8{"city"};
+    const order = [_]querymod.OrderBy{.{ .field = "score" }};
+    const idx = try orderedIndices(allocator, rows.items, &partition, &order);
+    defer allocator.free(idx);
+
+    // warsaw (first-seen) sorted asc: idx2 (score1), idx0 (score5) - then
+    // krakow sorted asc: idx3 (score2), idx1 (score9).
+    try std.testing.expectEqualSlices(usize, &.{ 2, 0, 3, 1 }, idx);
+}
+
+test "orderedIndices on zero rows returns an empty slice" {
+    const allocator = std.testing.allocator;
+    const rows = [_]Row{};
+    const idx = try orderedIndices(allocator, &rows, &.{}, &.{});
+    defer allocator.free(idx);
+    try std.testing.expectEqual(@as(usize, 0), idx.len);
+}
+
+test "orderedIndices propagates OutOfMemory without leaking" {
+    const allocator = std.testing.allocator;
+    var rows = try threeRowsOnePartition(allocator);
+    defer {
+        for (rows.items) |*r| r.deinit();
+        rows.deinit();
+    }
+    var failing = std.testing.FailingAllocator.init(allocator, .{ .fail_index = 0 });
+    try std.testing.expectError(error.OutOfMemory, orderedIndices(failing.allocator(), rows.items, &.{}, &.{}));
+}
+