From 21f2248a3c41dae53ba596121ef83413a7c6cb8f Mon Sep 17 00:00:00 2001
From: Igor Lins e Silva <4753812+igorls@users.noreply.github.com>
Date: Tue, 7 Apr 2026 17:21:37 -0300
Subject: [PATCH 1/3] fix: enable SQLite WAL mode and add consistent LIMIT to
 KG timeline
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- Enable WAL journal mode in _conn() for better concurrent read
  performance and reduced SQLITE_BUSY risk
- Add LIMIT 100 to entity-filtered timeline query (was unbounded,
  while global timeline already had LIMIT 100)

Findings: #8 (HIGH — no WAL mode), #22 (LOW — inconsistent limits)

Includes test infrastructure from PR #131.
92 tests pass.
---
 mempalace/knowledge_graph.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mempalace/knowledge_graph.py b/mempalace/knowledge_graph.py
index a2f8b54..226c92d 100644
--- a/mempalace/knowledge_graph.py
+++ b/mempalace/knowledge_graph.py
@@ -87,7 +87,9 @@ class KnowledgeGraph:
         conn.close()
 
     def _conn(self):
-        return sqlite3.connect(self.db_path, timeout=10)
+        conn = sqlite3.connect(self.db_path, timeout=10)
+        conn.execute("PRAGMA journal_mode=WAL")
+        return conn
 
     def _entity_id(self, name: str) -> str:
         return name.lower().replace(" ", "_").replace("'", "")
@@ -284,6 +286,7 @@ class KnowledgeGraph:
                 JOIN entities o ON t.object = o.id
                 WHERE (t.subject = ? OR t.object = ?)
                 ORDER BY t.valid_from ASC NULLS LAST
+                LIMIT 100
             """,
                 (eid, eid),
             ).fetchall()

From b45bff9db189ee1f7e412e4a61257e089b04819d Mon Sep 17 00:00:00 2001
From: Igor Lins e Silva <4753812+igorls@users.noreply.github.com>
Date: Tue, 7 Apr 2026 17:30:51 -0300
Subject: [PATCH 2/3] test: add WAL mode and entity timeline limit assertions

---
 tests/test_knowledge_graph.py | 17 +++++++++++++++++
 uv.lock                       | 10 ++++++++++
 2 files changed, 27 insertions(+)

diff --git a/tests/test_knowledge_graph.py b/tests/test_knowledge_graph.py
index a8fcd9a..d7d9838 100644
--- a/tests/test_knowledge_graph.py
+++ b/tests/test_knowledge_graph.py
@@ -107,6 +107,23 @@ class TestTimeline:
         tl = kg.timeline()
         assert len(tl) == 100  # LIMIT 100
 
+    def test_timeline_entity_has_limit(self, kg):
+        # Add > 100 triples all connected to a single entity
+        for i in range(105):
+            kg.add_triple(
+                "hub", "connects_to", f"spoke_{i}", valid_from=f"2025-01-{(i % 28) + 1:02d}"
+            )
+        tl = kg.timeline("hub")
+        assert len(tl) == 100  # LIMIT 100 on entity-filtered branch
+
+
+class TestWALMode:
+    def test_wal_mode_enabled(self, kg):
+        conn = kg._conn()
+        mode = conn.execute("PRAGMA journal_mode").fetchone()[0]
+        conn.close()
+        assert mode == "wal"
+
 
 class TestStats:
     def test_stats_empty(self, kg):
diff --git a/uv.lock b/uv.lock
index 0b00717..9d99313 100644
--- a/uv.lock
+++ b/uv.lock
@@ -966,6 +966,13 @@ dependencies = [
     { name = "pyyaml" },
 ]
 
+[package.optional-dependencies]
+dev = [
+    { name = "pytest", version = "8.4.2", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.10'" },
+    { name = "pytest", version = "9.0.3", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.10'" },
+    { name = "ruff" },
+]
+
 [package.dev-dependencies]
 dev = [
     { name = "pytest", version = "8.4.2", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.10'" },
@@ -976,8 +983,11 @@ dev = [
 [package.metadata]
 requires-dist = [
     { name = "chromadb", specifier = ">=0.4.0,<1" },
+    { name = "pytest", marker = "extra == 'dev'", specifier = ">=7.0" },
     { name = "pyyaml", specifier = ">=6.0" },
+    { name = "ruff", marker = "extra == 'dev'", specifier = ">=0.4.0" },
 ]
+provides-extras = ["dev"]
 
 [package.metadata.requires-dev]
 dev = [

From 6fa985eac2f86aff88f21b66fe35edf81f06611c Mon Sep 17 00:00:00 2001
From: Igor Lins e Silva <4753812+igorls@users.noreply.github.com>
Date: Tue, 7 Apr 2026 18:58:20 -0300
Subject: [PATCH 3/3] fix: update dialect tests for PR #147 stats API and
 remove unused fixture param

---
 tests/conftest.py     | 2 +-
 tests/test_dialect.py | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/conftest.py b/tests/conftest.py
index d0c30c2..22b5e42 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -35,7 +35,7 @@ from mempalace.knowledge_graph import KnowledgeGraph  # noqa: E402
 
 
 @pytest.fixture(scope="session", autouse=True)
-def _isolate_home(tmp_path_factory):
+def _isolate_home():
     """Ensure HOME points to a temp dir for the entire test session.
 
     The env vars were already set at module level (above) so that
diff --git a/tests/test_dialect.py b/tests/test_dialect.py
index 2ef1df6..8edc7ec 100644
--- a/tests/test_dialect.py
+++ b/tests/test_dialect.py
@@ -109,11 +109,11 @@ class TestCompressionStats:
         original = "We decided to use GraphQL instead of REST. " * 10
         compressed = d.compress(original)
         stats = d.compression_stats(original, compressed)
-        assert stats["ratio"] > 1
-        assert stats["original_chars"] > stats["compressed_chars"]
+        assert stats["size_ratio"] > 1
+        assert stats["original_chars"] > stats["summary_chars"]
 
     def test_count_tokens(self):
-        assert Dialect.count_tokens("hello world") == len("hello world") // 3
+        assert Dialect.count_tokens("hello world") == 2
 
 
 class TestZettelEncoding: