diff --git a/mateclaw-server/src/main/java/vip/mate/memory/service/MemoryRecallService.java b/mateclaw-server/src/main/java/vip/mate/memory/service/MemoryRecallService.java
index 6cf287f7..df10190d 100644
--- a/mateclaw-server/src/main/java/vip/mate/memory/service/MemoryRecallService.java
+++ b/mateclaw-server/src/main/java/vip/mate/memory/service/MemoryRecallService.java
@@ -35,6 +35,22 @@ public class MemoryRecallService {
 
     private static final int MAX_QUERY_HASHES = 32;
 
+    /** mate_memory_recall.filename is VARCHAR(256). Bound the value here so an
+     *  over-long section key (path + '#' + H2 heading slug, see #461) can never
+     *  blow past the column. Truncating at the entry point keeps the select /
+     *  insert / update branches below operating on the same value, so the
+     *  dup-key concurrency fallback still matches. */
+    static final int MAX_FILENAME_LENGTH = 255;
+
+    /** Truncate {@code filename} to {@link #MAX_FILENAME_LENGTH}. Package-private
+     *  for direct unit testing. CJK chars live in the BMP, so {@code substring}
+     *  cannot split a surrogate pair. */
+    static String truncateFilename(String filename) {
+        return filename.length() > MAX_FILENAME_LENGTH
+                ? filename.substring(0, MAX_FILENAME_LENGTH)
+                : filename;
+    }
+
     /**
      * 记录一次文件召回
      */
@@ -42,6 +58,9 @@ public class MemoryRecallService {
         if (agentId == null || filename == null || filename.isBlank()) {
             return;
         }
+        // 写库前硬截断：覆盖所有调用路径（含 trackActiveRetrieval 透传的外部 filename），
+        // 防 filename 突破 VARCHAR(256) 导致写入失败（#461）
+        filename = truncateFilename(filename);
 
         // snippet preview 只取前 200 字符（避免对大文件做完整 SHA-256）
         String preview = snippetText != null && snippetText.length() > 200
diff --git a/mateclaw-server/src/main/java/vip/mate/memory/service/MemoryRecallTracker.java b/mateclaw-server/src/main/java/vip/mate/memory/service/MemoryRecallTracker.java
index 0eaae68a..49449f20 100644
--- a/mateclaw-server/src/main/java/vip/mate/memory/service/MemoryRecallTracker.java
+++ b/mateclaw-server/src/main/java/vip/mate/memory/service/MemoryRecallTracker.java
@@ -126,12 +126,20 @@ public class MemoryRecallTracker {
         return count;
     }
 
-    private String sanitizeSectionKey(String heading) {
+    /** Max length of a section slug — keeps the full key (path + '#' + slug)
+     *  well under the mate_memory_recall.filename VARCHAR(256) ceiling even
+     *  when an LLM writes an over-long H2 heading. CJK chars live in the BMP,
+     *  so {@code substring} can never split a surrogate pair here. */
+    static final int MAX_SECTION_SLUG = 200;
+
+    /** Package-private for direct unit testing of the slug/truncation logic. */
+    static String sanitizeSectionKey(String heading) {
         // "## Some Title" -> "some-title"
-        return heading.replaceFirst("^#+\\s*", "")
+        String slug = heading.replaceFirst("^#+\\s*", "")
                 .toLowerCase()
                 .replaceAll("[^a-z0-9\\u4e00-\\u9fff]+", "-")
                 .replaceAll("^-|-$", "");
+        return slug.length() > MAX_SECTION_SLUG ? slug.substring(0, MAX_SECTION_SLUG) : slug;
     }
 
     /**
diff --git a/mateclaw-server/src/main/resources/prompts/memory/summarize-system.txt b/mateclaw-server/src/main/resources/prompts/memory/summarize-system.txt
index 9a2774cf..8ee986e7 100644
--- a/mateclaw-server/src/main/resources/prompts/memory/summarize-system.txt
+++ b/mateclaw-server/src/main/resources/prompts/memory/summarize-system.txt
@@ -42,7 +42,7 @@ MEMORY.md 与 PROFILE.md 会被**无条件注入每一次对话的系统提示**
 
 字段说明：
 - `should_update`: 布尔值，是否有任何需要更新的内容。如果为 false，其余字段应为 null
-- `daily_entry`: 字符串或 null。要追加到今日 daily note 的内容（markdown 格式，以时间戳开头如 "## HH:mm ..."）
+- `daily_entry`: 字符串或 null。要追加到今日 daily note 的内容（markdown 格式，以时间戳开头如 "## HH:mm 简要事件标题"）。**二级标题（##）保持简短（不超过 30 字），只概括事件主题；事件细节、数字、过程写进标题下方的正文，不要堆进标题——过长的标题会导致下游索引截断。**
 - `memory_update`: 字符串或 null。MEMORY.md 的完整新内容（已合并现有内容，不是增量）。仅当有需要新增或修改的**跨项目稳定**信息时才填写
 - `profile_update`: 字符串或 null。PROFILE.md 的完整新内容（已合并现有内容，不是增量）。仅当用户身份/偏好有显著变化时才填写
 - `structured_entries`: 数组或 null。把适合按条目检索的**具体事实**路由到结构化记忆，每个元素形如 `{"type": "...", "key": "...", "content": "..."}`：
diff --git a/mateclaw-server/src/test/java/vip/mate/memory/service/MemoryRecallFilenameTruncationTest.java b/mateclaw-server/src/test/java/vip/mate/memory/service/MemoryRecallFilenameTruncationTest.java
new file mode 100644
index 00000000..67a50524
--- /dev/null
+++ b/mateclaw-server/src/test/java/vip/mate/memory/service/MemoryRecallFilenameTruncationTest.java
@@ -0,0 +1,111 @@
+package vip.mate.memory.service;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Guards the {@code mate_memory_recall.filename} VARCHAR(256) ceiling against
+ * over-long section keys (file path + '#' + a long H2 heading slug). See #461.
+ * <p>
+ * Two boundaries are covered as pure functions, no Spring context needed:
+ * <ul>
+ *   <li>{@link MemoryRecallTracker#sanitizeSectionKey} — slug-side cap</li>
+ *   <li>{@link MemoryRecallService#truncateFilename} — write-side cap</li>
+ * </ul>
+ */
+class MemoryRecallFilenameTruncationTest {
+
+    /** Repeated CJK filler so a heading can be grown past any threshold. */
+    private static final String CN = "用户要求设置每日财经早报定时任务，每天早上推送汇总报告到指定群组";
+
+    @Nested
+    @DisplayName("sanitizeSectionKey — slug-side cap")
+    class SanitizeSectionKey {
+
+        @Test
+        @DisplayName("normal CJK heading is slugified untouched (no false truncation)")
+        void normalCjkHeadingPreserved() {
+            String slug = MemoryRecallTracker.sanitizeSectionKey("## 08:30 用户设置每日财经早报定时任务");
+            // "## " stripped, ':' and spaces → '-', CJK kept; "08-30-用户设置每日财经早报定时任务"
+            assertEquals("08-30-用户设置每日财经早报定时任务", slug);
+            assertTrue(slug.length() <= MemoryRecallTracker.MAX_SECTION_SLUG);
+        }
+
+        @Test
+        @DisplayName("over-long CJK heading slug is capped at MAX_SECTION_SLUG and never throws")
+        void overLongCjkHeadingCapped() {
+            StringBuilder heading = new StringBuilder("## ");
+            while (heading.length() < MemoryRecallTracker.MAX_SECTION_SLUG + 200) {
+                heading.append(CN);
+            }
+            String slug = assertDoesNotThrow(() -> MemoryRecallTracker.sanitizeSectionKey(heading.toString()));
+            assertTrue(slug.length() <= MemoryRecallTracker.MAX_SECTION_SLUG,
+                    "slug must not exceed MAX_SECTION_SLUG, was " + slug.length());
+        }
+
+        @Test
+        @DisplayName("ascii-only heading collapses runs of non-alnum to a single '-'")
+        void asciiHeadingSlugified() {
+            assertEquals("some-title-here", MemoryRecallTracker.sanitizeSectionKey("## Some Title Here"));
+        }
+    }
+
+    @Nested
+    @DisplayName("truncateFilename — write-side cap")
+    class TruncateFilename {
+
+        @Test
+        @DisplayName("filename at/below the cap is returned unchanged")
+        void underCapUnchanged() {
+            String filename = "memory/2026-06-05.md#08-30-用户设置每日财经早报定时任务";
+            assertTrue(filename.length() <= MemoryRecallService.MAX_FILENAME_LENGTH);
+            assertSame(filename, MemoryRecallService.truncateFilename(filename),
+                    "under-cap values must pass through without copying");
+        }
+
+        @Test
+        @DisplayName("filename over the cap is truncated to MAX_FILENAME_LENGTH")
+        void overCapTruncated() {
+            StringBuilder filename = new StringBuilder("memory/2026-06-05.md#");
+            while (filename.length() < MemoryRecallService.MAX_FILENAME_LENGTH + 100) {
+                filename.append(CN);
+            }
+            String out = MemoryRecallService.truncateFilename(filename.toString());
+            assertEquals(MemoryRecallService.MAX_FILENAME_LENGTH, out.length(),
+                    "over-cap value must be exactly MAX_FILENAME_LENGTH");
+        }
+
+        @Test
+        @DisplayName("truncation keeps the date prefix intact (computeFreshness still parses it)")
+        void datePrefixPreserved() {
+            StringBuilder filename = new StringBuilder("memory/2026-06-05.md#");
+            while (filename.length() < MemoryRecallService.MAX_FILENAME_LENGTH + 100) {
+                filename.append(CN);
+            }
+            String out = MemoryRecallService.truncateFilename(filename.toString());
+            // The leading path/date — the only part computeFreshness uses — survives.
+            assertTrue(out.startsWith("memory/2026-06-05.md"), "date prefix must survive truncation");
+            int hash = out.indexOf('#');
+            assertTrue(hash > 0 && hash < out.length(), "section anchor must still be present");
+        }
+    }
+
+    @Test
+    @DisplayName("full daily-note section key stays under the DB column ceiling end-to-end")
+    void endToEndWithinColumnCeiling() {
+        // Reproduce MemoryRecallTracker's key assembly on an over-long heading.
+        String dailyFile = "memory/2026-06-05.md";
+        StringBuilder heading = new StringBuilder("## 08:30 ");
+        while (heading.length() < MemoryRecallTracker.MAX_SECTION_SLUG + 300) {
+            heading.append(CN);
+        }
+        String sectionKey = dailyFile + "#" + MemoryRecallTracker.sanitizeSectionKey(heading.toString());
+        // Even after the write-side fallback, the stored value must fit VARCHAR(256).
+        String stored = MemoryRecallService.truncateFilename(sectionKey);
+        assertTrue(stored.length() <= 255,
+                "stored filename must fit VARCHAR(256), was " + stored.length());
+    }
+}