diff --git a/internal/common/logger.go b/internal/common/logger.go
index 3d0cae1180..6ef806dcae 100644
--- a/internal/common/logger.go
+++ b/internal/common/logger.go
@@ -421,8 +421,13 @@ func ErrorCtx(ctx context.Context, msg string, err error, fields ...zap.Field) {
 	Logger.Error(detail, append(sessionFields(ctx), fields...)...)
 }
 
-// IsDebugEnabled returns true if debug logging is enabled.
+// IsDebugEnabled returns true if debug logging is enabled. It is safe to call
+// before InitLogger (e.g. in unit tests): an uninitialized level reports false,
+// matching the production default of info-level logging.
 func IsDebugEnabled() bool {
+	if Logger == nil {
+		return false
+	}
 	return atomicLevel.Enabled(zapcore.DebugLevel)
 }
 
diff --git a/internal/engine/elasticsearch/chunk.go b/internal/engine/elasticsearch/chunk.go
index 4f7e383374..42211851b6 100644
--- a/internal/engine/elasticsearch/chunk.go
+++ b/internal/engine/elasticsearch/chunk.go
@@ -3575,7 +3575,12 @@ func parseOrderByExpr(orderBy *types.OrderByExpr) []map[string]interface{} {
 			direction = "desc"
 		}
 
-		// Skip id field (cannot order by text field)
+		// Skip id field (cannot order by text field). The logical "id" column is
+		// shimmed from the ES _id in the response path, but ordering on _id
+		// requires indices.id_field_data, which is disabled by default on the
+		// bundled Elasticsearch 8.x deployment and would make every id-ordered
+		// query fail at runtime. Callers that need deep pagination must supply a
+		// real stored, sortable field instead of relying on the logical id.
 		if field.Field == "id" {
 			continue
 		}
diff --git a/internal/engine/elasticsearch/parse_orderby_test.go b/internal/engine/elasticsearch/parse_orderby_test.go
new file mode 100644
index 0000000000..adcefa949f
--- /dev/null
+++ b/internal/engine/elasticsearch/parse_orderby_test.go
@@ -0,0 +1,61 @@
+package elasticsearch
+
+import (
+	"reflect"
+	"testing"
+
+	"ragflow/internal/engine/types"
+)
+
+// TestParseOrderByExprSkipsLogicalID guards that the logical "id" column is NOT
+// translated into an Elasticsearch _id sort. Ordering on _id requires
+// indices.id_field_data, which is disabled by default on the bundled
+// Elasticsearch 8.x deployment; emitting a _id sort would make every id-ordered
+// query (knowledge_compile merge reads, dataset structure graph) fail at runtime.
+// The caller that needs deep pagination must supply a real stored, sortable field
+// instead of relying on the logical id.
+func TestParseOrderByExprSkipsLogicalID(t *testing.T) {
+	cases := []struct {
+		name string
+		expr *types.OrderByExpr
+		want []map[string]interface{}
+	}{
+		{
+			name: "asc id is skipped (no _id sort)",
+			expr: (&types.OrderByExpr{}).Asc("id"),
+			want: nil,
+		},
+		{
+			name: "desc id is skipped (no _id sort)",
+			expr: (&types.OrderByExpr{}).Desc("id"),
+			want: nil,
+		},
+		{
+			name: "id mixed with other fields keeps the others, drops id",
+			expr: (&types.OrderByExpr{}).Asc("weight_flt").Asc("id"),
+			want: []map[string]interface{}{
+				{"weight_flt": map[string]interface{}{"order": "asc", "unmapped_type": "float"}},
+			},
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := parseOrderByExpr(tc.expr)
+			if !reflect.DeepEqual(got, tc.want) {
+				t.Fatalf("parseOrderByExpr(%v) = %#v, want %#v", tc.expr, got, tc.want)
+			}
+		})
+	}
+}
+
+// TestParseOrderByExprIDNotDroppedToIDMetadata is the explicit regression guard:
+// parseOrderByExpr must never emit a {"_id": ...} sort for the logical id column.
+func TestParseOrderByExprIDNotDroppedToIDMetadata(t *testing.T) {
+	got := parseOrderByExpr((&types.OrderByExpr{}).Asc("id"))
+	for _, sort := range got {
+		if _, ok := sort["_id"]; ok {
+			t.Fatalf("parseOrderByExpr(id) emitted a _id sort %#v; this breaks on default ES 8.x", sort)
+		}
+	}
+}
diff --git a/internal/ingestion/knowledge_compile/consumer.go b/internal/ingestion/knowledge_compile/consumer.go
index b999f5148c..251615035f 100644
--- a/internal/ingestion/knowledge_compile/consumer.go
+++ b/internal/ingestion/knowledge_compile/consumer.go
@@ -438,20 +438,25 @@ func (c *Consumer) RebuildDataset(ctx context.Context, tenant, kb, mode string)
 	if err != nil {
 		return fmt.Errorf("knowledge_compile: rebuild list docs: %w", err)
 	}
+	// Recover each document's compile variants from its compiled products. The
+	// read is batched (LoadDocProductsByDocs) and processed in bounded chunks so
+	// the in-flight product set never exceeds one batch (docProductsBatchSize)
+	// instead of the entire KB — the previous loop loaded one document at a time
+	// and released it; a single full-KB batch read would have retained every
+	// document's products (including vectors) until recovery finished.
+	variantsByDoc, err := c.recoverDocVariantsBatch(ctx, tenant, kb, docs)
+	if err != nil {
+		return fmt.Errorf("knowledge_compile: rebuild recover variants: %w", err)
+	}
 	for _, docID := range docs {
-		variants, taskTypes, rerr := c.recoverDocTypes(ctx, tenant, kb, docID)
-		if rerr != nil {
-			// O2a hard failure: abort the rebuild so an unknown template kind
-			// cannot leave the doc's dataset-level products unrebuilt.
-			return fmt.Errorf("knowledge_compile: rebuild recover variants %s: %w", docID, rerr)
-		}
-		if len(variants) == 0 {
+		vr := variantsByDoc[docID]
+		if len(vr.variants) == 0 {
 			// Documents without compiled products do not contribute to any
 			// dataset-level variant and must not enqueue an empty completion
 			// event that falls back to the legacy all-products path.
 			continue
 		}
-		if perr := rs.Publish(ctx, tenant, kb, docID, string(EventTypeCompleted), variants, taskTypes); perr != nil {
+		if perr := rs.Publish(ctx, tenant, kb, docID, string(EventTypeCompleted), vr.variants, vr.taskTypes); perr != nil {
 			return fmt.Errorf("knowledge_compile: rebuild republish %s: %w", docID, perr)
 		}
 	}
@@ -475,27 +480,11 @@ func (c *Consumer) defaultDocLister(ctx context.Context, tenant, kb string) ([]s
 	return dao.NewDocumentDAO().ListIDsByKBIDWithOptions(ctx, c.db, dao.DocumentListOptions{KbID: kb})
 }
 
-// recoverDocTypes reconstructs the compile-type and frontend task-type sets a
-// document produced by reading its persisted doc-level products and mapping
-// each product's canonical compilation kind through the
-// shared kind mappings.
-// It is used by RebuildDataset (B1) so the republished completed events carry
-// the variants needed to route the dataset-level re-compile (tree nav, structure
-// merge, wiki merge) — a nil/empty Variants would fall back to the legacy
-// unified path and tree nav could not be rebuilt.
-//
-// KindToVariant (O2a) is a fixed whitelist that HARD-FAILS on unknown kinds: a
-// product whose kind is not in the whitelist is a corrupt/unsupported state and
-// the rebuild must abort (returning an error) rather than silently drop the
-// variant and leave the doc's dataset-level products unrebuilt. A product
-// without an authoritative kind falls back to its reverse-mapped variant (which
-// itself must be whitelist-valid, enforced by KwdToVariant in the Reader). The
-// Both returned slices are sorted and de-duplicated.
-func (c *Consumer) recoverDocTypes(ctx context.Context, tenant, kb, docID string) ([]string, []string, error) {
-	products, err := c.reader.LoadDocProducts(ctx, tenant, kb, docID)
-	if err != nil {
-		return nil, nil, fmt.Errorf("knowledge_compile: recover variants load doc %s: %w", docID, err)
-	}
+// recoverDocTypesFrom maps a document's already-loaded compiled products to its
+// variant and frontend task-type sets. Splitting the mapping from the read lets
+// the rebuild path reuse a single batch read (LoadDocProductsByDocs) instead of
+// one read per document.
+func recoverDocTypesFrom(products []kccommon.Product) ([]string, []string, error) {
 	seenVariants := map[string]struct{}{}
 	seenTaskTypes := map[string]struct{}{}
 	var variants []string
@@ -505,7 +494,7 @@ func (c *Consumer) recoverDocTypes(ctx context.Context, tenant, kb, docID string
 			v, err := kccommon.KindToVariant(p.Kind)
 			if err != nil {
 				// O2a hard failure: do not continue with an incomplete variant set.
-				return nil, nil, fmt.Errorf("knowledge_compile: recover variants doc %s kind %q: %w", docID, p.Kind, err)
+				return nil, nil, fmt.Errorf("knowledge_compile: recover variants kind %q: %w", p.Kind, err)
 			}
 			if _, dup := seenVariants[string(v)]; !dup {
 				seenVariants[string(v)] = struct{}{}
@@ -540,6 +529,43 @@ func (c *Consumer) recoverDocTypes(ctx context.Context, tenant, kb, docID string
 	return variants, taskTypes, nil
 }
 
+// docVariantResult holds the recovered compile variants and frontend task types
+// for one document.
+type docVariantResult struct {
+	variants  []string
+	taskTypes []string
+}
+
+// recoverDocVariantsBatch loads the compiled products for the given documents and
+// maps each to its variant/task-type sets. Documents are walked in
+// docProductsBatchSize chunks so the products held in memory at any moment are
+// limited to a single batch instead of the whole KB (the previous loop loaded one
+// document at a time and released it; a single full-KB batch read would retain
+// every document's products — including vectors — until recovery finished).
+func (c *Consumer) recoverDocVariantsBatch(ctx context.Context, tenant, kb string, docs []string) (map[string]docVariantResult, error) {
+	out := make(map[string]docVariantResult, len(docs))
+	for start := 0; start < len(docs); start += docProductsBatchSize {
+		end := start + docProductsBatchSize
+		if end > len(docs) {
+			end = len(docs)
+		}
+		productsByDoc, err := c.reader.LoadDocProductsByDocs(ctx, tenant, kb, docs[start:end])
+		if err != nil {
+			return nil, err
+		}
+		for _, docID := range docs[start:end] {
+			variants, taskTypes, rerr := recoverDocTypesFrom(productsByDoc[docID])
+			if rerr != nil {
+				// O2a hard failure: abort the rebuild so an unknown template kind
+				// cannot leave the doc's dataset-level products unrebuilt.
+				return nil, fmt.Errorf("knowledge_compile: rebuild recover variants %s: %w", docID, rerr)
+			}
+			out[docID] = docVariantResult{variants: variants, taskTypes: taskTypes}
+		}
+	}
+	return out, nil
+}
+
 // filterWikiPageCandidates returns ONLY the wiki page products the dataset-level
 // wiki merge may fold. It drops every non-wiki product (tree/structure/nav) so
 // those never enter the wiki Dedup/KNN/WriteMerged path, and within the wiki
@@ -885,11 +911,27 @@ func (c *Consumer) processBatch(ctx context.Context, tenant, kb, token string, e
 		return err
 	}
 	entityMerged = append(entityMerged, topicMerged...)
-	if len(wikiDiff.affectedKeys) > 0 {
-		if err := c.deleteMissingScopedWikiPages(ctx, tenant, kb, token, wikiDiff.affectedKeys, entityMerged); err != nil {
+	// Load the dataset's merged wiki pages once and reuse the snapshot for both
+	// the scoped-page deletion and the topic-key seed below, instead of reading
+	// the same pages twice per merge step.
+	var existingPages []kccommon.Product
+	if pageReader, ok := c.reader.(mergedWikiPageReader); ok {
+		existingPages, err = pageReader.LoadMergedWikiPages(ctx, tenant, kb)
+		if err != nil {
 			return err
 		}
 	}
+	deletedIDs := []string{}
+	if len(wikiDiff.affectedKeys) > 0 {
+		deletedIDs, err = c.deleteMissingScopedWikiPages(ctx, tenant, kb, token, wikiDiff.affectedKeys, entityMerged, existingPages)
+		if err != nil {
+			return err
+		}
+	}
+	excluded := make(map[string]struct{}, len(deletedIDs))
+	for _, id := range deletedIDs {
+		excluded[id] = struct{}{}
+	}
 	c.reportProgress(ctx, tenant, kb, token, taskTypes, 0.58, "merging_by_slug", fmt.Sprintf("Merging knowledge pages by slug: %d", len(entityMerged)))
 	// Entity pages have stable page identity and must bypass topic-mode KNN and
 	// Page-specific entity/concept merging. Only topic-mode pages continue below.
@@ -905,23 +947,14 @@ func (c *Consumer) processBatch(ctx context.Context, tenant, kb, token string, e
 	// Diagnostics: after batch dedup, verify the per-doc products still carry
 	// their embedding before the KNN/merge path consumes cand.Vector. If
 	// candidates show 0 vectors while incoming had vectors, Dedup is dropping
-	// them and both the KNN lookups and the merged rows lose embeddings.
-	{
-		incomingVec, candVec := 0, 0
-		for _, p := range incoming {
-			if len(p.Vector) > 0 {
-				incomingVec++
-			}
-		}
-		for _, p := range candidates {
-			if len(p.Vector) > 0 {
-				candVec++
-			}
-		}
+	// them and both the KNN lookups and the merged rows lose embeddings. Gated to
+	// debug: the counting below allocates even in quiet production.
+	if common.IsDebugEnabled() {
+		inVec, candVec := computeDedupVectorAudit(incoming, candidates)
 		common.Info("knowledge_compile: dedup vector audit",
 			zap.String("kb_id", kb),
 			zap.Int("incoming", len(incoming)),
-			zap.Int("incoming_with_vector", incomingVec),
+			zap.Int("incoming_with_vector", inVec),
 			zap.Int("candidates", len(candidates)),
 			zap.Int("candidates_with_vector", candVec))
 	}
@@ -931,17 +964,9 @@ func (c *Consumer) processBatch(ctx context.Context, tenant, kb, token string, e
 	// against the wiki_page rows WriteMerged emits (they differ when KNN merges a
 	// candidate into an existing merged row, when DecideBatch returns distinct new
 	// rows, or when candidates of the same variant collapse in-memory). This is
-	// what explains "39 wiki_page written vs 21 KNN requests".
-	{
-		byVariant := map[string]int{}
-		var wikiPageSlugs []string
-		for _, cand := range candidates {
-			v := string(cand.Variant)
-			byVariant[v]++
-			if cand.Variant == kccommon.VariantWiki {
-				wikiPageSlugs = append(wikiPageSlugs, candidateIdentity(cand))
-			}
-		}
+	// what explains "39 wiki_page written vs 21 KNN requests". Gated to debug.
+	if common.IsDebugEnabled() {
+		byVariant, wikiPageSlugs := computeCandidatesBreakdown(candidates)
 		common.Info("knowledge_compile: candidates breakdown",
 			zap.String("kb_id", kb),
 			zap.Int("candidates", len(candidates)),
@@ -953,11 +978,6 @@ func (c *Consumer) processBatch(ctx context.Context, tenant, kb, token string, e
 	// mirroring _struct_doc_storage_dedup_batch. Candidates that KNN-hit
 	// the same existing merged row are grouped so the row is merged/updated once
 	// instead of being rewritten per candidate.
-	type mergeGroup struct {
-		existing   kccommon.Product
-		candidates []kccommon.Product
-		score      float64
-	}
 	groupsByID := make(map[string]*mergeGroup, len(candidates))
 	var (
 		unmatchedMu sync.Mutex
@@ -967,24 +987,10 @@ func (c *Consumer) processBatch(ctx context.Context, tenant, kb, token string, e
 	// Exact topic recall is independent of page-content KNN. A page can use
 	// different wording from the existing topic while still belonging to the
 	// same topic, so consult the current dataset pages before running KNN.
-	topicPagesByKey := make(map[string]kccommon.Product)
-	if pageReader, ok := c.reader.(mergedWikiPageReader); ok {
-		existingPages, err := pageReader.LoadMergedWikiPages(ctx, tenant, kb)
-		if err != nil {
-			return err
-		}
-		for _, page := range existingPages {
-			if !isTopicPage(page) {
-				continue
-			}
-			key := topicKey(productTopic(page))
-			if key != "" {
-				if _, exists := topicPagesByKey[key]; !exists {
-					topicPagesByKey[key] = page
-				}
-			}
-		}
-	}
+	// Seed with the surviving topic pages (excluding the ones this step just
+	// deleted), reproducing the post-deletion snapshot the previous double-read
+	// produced without a second engine query.
+	topicPagesByKey := buildTopicPagesByKey(existingPages, excluded)
 	// The KNN pass is docengine-bounded (vector search), not CPU-bounded, so we
 	// fan it out across the shared global compilerPool (vCPU-sized). Output order
 	// is irrelevant: merged rows are upserted by their idempotent dataset-level
@@ -1116,25 +1122,13 @@ func (c *Consumer) processBatch(ctx context.Context, tenant, kb, token string, e
 		// Diagnostics: summarize the KNN groups before the LLM merge decision so
 		// the reader can see which existing merged rows were hit and by how many
 		// candidates (e.g. whether a "吕布" candidate hit an existing 吕布 row and
-		// was then judged by the LLM).
-		{
-			type groupDump struct {
-				Existing   string   `json:"existing"`
-				Candidates []string `json:"candidates"`
-				Score      float64  `json:"score"`
-			}
-			dumps := make([]groupDump, 0, len(groupsByID))
-			for _, g := range groupsByID {
-				cands := make([]string, 0, len(g.candidates))
-				for _, cand := range g.candidates {
-					cands = append(cands, candidateIdentity(cand))
-				}
-				dumps = append(dumps, groupDump{Existing: candidateIdentity(g.existing), Candidates: cands, Score: g.score})
-			}
+		// was then judged by the LLM). Gated to debug: the slice/map construction
+		// below allocates even in quiet production and is only useful when tracing.
+		if common.IsDebugEnabled() {
 			common.Info("knowledge_compile: KNN groups for DecideBatch",
 				zap.String("kb_id", kb),
 				zap.Int("groups", len(groupsByID)),
-				zap.Any("groups_detail", dumps))
+				zap.Any("groups_detail", computeKNNGroupDumps(groupsByID)))
 		}
 		batched := make([]MergeGroup, 0, len(groupsByID))
 		for _, g := range groupsByID {
@@ -1404,11 +1398,16 @@ type mergedWikiPageDeleter interface {
 	DeleteMergedWikiPages(ctx context.Context, tenant, kb string, ids []string) error
 }
 
-func (c *Consumer) deleteMissingScopedWikiPages(ctx context.Context, tenant, kb, token string, affected map[string]struct{}, current []kccommon.Product) error {
-	reader, readerOK := c.reader.(mergedWikiPageReader)
+// deleteMissingScopedWikiPages removes the merged wiki pages whose contribution
+// was dropped by this batch (present in affectedKeys but no longer in current).
+// It takes the already-loaded merged pages (existingPages) so the merge step can
+// reuse a single LoadMergedWikiPages snapshot; the caller passes the same slice
+// it uses to seed the topic-key map, excluding the returned deleted IDs.
+func (c *Consumer) deleteMissingScopedWikiPages(ctx context.Context, tenant, kb, token string, affected map[string]struct{}, current, existingPages []kccommon.Product) ([]string, error) {
+	_, readerOK := c.reader.(mergedWikiPageReader)
 	deleter, writerOK := c.writer.(mergedWikiPageDeleter)
 	if !readerOK || !writerOK {
-		return fmt.Errorf("knowledge_compile: scoped Wiki cleanup is unsupported")
+		return nil, fmt.Errorf("knowledge_compile: scoped Wiki cleanup is unsupported")
 	}
 	present := make(map[string]struct{}, len(current))
 	for _, page := range current {
@@ -1416,12 +1415,8 @@ func (c *Consumer) deleteMissingScopedWikiPages(ctx context.Context, tenant, kb,
 			present[key] = struct{}{}
 		}
 	}
-	existing, err := reader.LoadMergedWikiPages(ctx, tenant, kb)
-	if err != nil {
-		return err
-	}
 	ids := make([]string, 0)
-	for _, page := range existing {
+	for _, page := range existingPages {
 		key := wikiPageMergeKey(page)
 		if _, scoped := affected[key]; !scoped {
 			continue
@@ -1431,11 +1426,39 @@ func (c *Consumer) deleteMissingScopedWikiPages(ctx context.Context, tenant, kb,
 		}
 	}
 	if len(ids) == 0 {
-		return nil
+		return nil, nil
 	}
-	return c.withWriteLock(ctx, kb, token, func() error {
+	if err := c.withWriteLock(ctx, kb, token, func() error {
 		return deleter.DeleteMergedWikiPages(ctx, tenant, kb, ids)
-	})
+	}); err != nil {
+		return nil, err
+	}
+	return ids, nil
+}
+
+// buildTopicPagesByKey indexes the topic-mode merged pages by their topic key,
+// skipping any page whose ID is in excludedIDs. excludedIDs are the page IDs this
+// process deletes in the same merge step; skipping them reproduces the
+// post-deletion snapshot the merge step previously obtained via a second
+// LoadMergedWikiPages call, without a second read.
+func buildTopicPagesByKey(pages []kccommon.Product, excludedIDs map[string]struct{}) map[string]kccommon.Product {
+	out := make(map[string]kccommon.Product)
+	for _, page := range pages {
+		if !isTopicPage(page) {
+			continue
+		}
+		if _, del := excludedIDs[page.ID]; del {
+			continue
+		}
+		key := topicKey(productTopic(page))
+		if key == "" {
+			continue
+		}
+		if _, exists := out[key]; !exists {
+			out[key] = page
+		}
+	}
+	return out
 }
 
 func refreshWikiProductVectors(ctx context.Context, tenant string, products []kccommon.Product) []kccommon.Product {
@@ -1889,3 +1912,83 @@ func (c *Consumer) removeNavLocked(ctx context.Context, tenant, kb, token string
 		return nil
 	})
 }
+
+// mergeGroup groups the KNN/LLM merge candidates that resolve to the same
+// existing merged row, so the row is merged/updated once instead of being
+// rewritten per candidate.
+type mergeGroup struct {
+	existing   kccommon.Product
+	candidates []kccommon.Product
+	score      float64
+}
+
+// groupDump is the debug-only serialization of a mergeGroup for the KNN
+// pre-LLM-merge diagnostic log.
+type groupDump struct {
+	Existing   string   `json:"existing"`
+	Candidates []string `json:"candidates"`
+	Score      float64  `json:"score"`
+}
+
+// computeDedupVectorAudit counts how many incoming and post-dedup candidates
+// still carry an embedding, surfacing whether Dedup is dropping vectors before
+// the KNN/merge path consumes cand.Vector.
+func computeDedupVectorAudit(incoming, candidates []kccommon.Product) (int, int) {
+	incomingVec, candVec := 0, 0
+	for _, p := range incoming {
+		if len(p.Vector) > 0 {
+			incomingVec++
+		}
+	}
+	for _, p := range candidates {
+		if len(p.Vector) > 0 {
+			candVec++
+		}
+	}
+	return incomingVec, candVec
+}
+
+// computeCandidatesBreakdown breaks the KNN-input set down by variant and lists
+// the wiki_page slugs, so a reader can reconcile candidate counts against the
+// merged rows WriteMerged emits.
+func computeCandidatesBreakdown(candidates []kccommon.Product) (map[string]int, []string) {
+	byVariant := map[string]int{}
+	var wikiPageSlugs []string
+	for _, cand := range candidates {
+		v := string(cand.Variant)
+		byVariant[v]++
+		if cand.Variant == kccommon.VariantWiki {
+			wikiPageSlugs = append(wikiPageSlugs, candidateIdentity(cand))
+		}
+	}
+	return byVariant, wikiPageSlugs
+}
+
+// computeDocProductsVectorAudit counts how many loaded per-doc products carry an
+// embedding and the (deduped) vector dimensions, surfacing when
+// VectorFromChunkMap fails to restore the vector.
+func computeDocProductsVectorAudit(products []kccommon.Product) (int, map[int]int) {
+	vecCount := 0
+	dims := map[int]int{}
+	for _, p := range products {
+		if dim := len(p.Vector); dim > 0 {
+			vecCount++
+			dims[dim]++
+		}
+	}
+	return vecCount, dims
+}
+
+// computeKNNGroupDumps serializes the KNN groups before the LLM merge decision
+// for the debug-only diagnostic log.
+func computeKNNGroupDumps(groups map[string]*mergeGroup) []groupDump {
+	dumps := make([]groupDump, 0, len(groups))
+	for _, g := range groups {
+		cands := make([]string, 0, len(g.candidates))
+		for _, cand := range g.candidates {
+			cands = append(cands, candidateIdentity(cand))
+		}
+		dumps = append(dumps, groupDump{Existing: candidateIdentity(g.existing), Candidates: cands, Score: g.score})
+	}
+	return dumps
+}
diff --git a/internal/ingestion/knowledge_compile/fake_engine_test.go b/internal/ingestion/knowledge_compile/fake_engine_test.go
index e0f694698f..bce9b24e67 100644
--- a/internal/ingestion/knowledge_compile/fake_engine_test.go
+++ b/internal/ingestion/knowledge_compile/fake_engine_test.go
@@ -17,7 +17,9 @@ package knowledge_compile
 
 import (
 	"context"
+	"fmt"
 
+	"ragflow/internal/common"
 	"ragflow/internal/engine/types"
 
 	"gorm.io/gorm"
@@ -35,6 +37,16 @@ type fakeEngine struct {
 	searchChunks []map[string]interface{}
 	// lastSearchReq captures the most recent SearchRequest for assertions.
 	lastSearchReq *types.SearchRequest
+	// searchReqs accumulates every SearchRequest in call order, so tests can
+	// assert on multi-search paths (e.g. chunked batch reads).
+	searchReqs []*types.SearchRequest
+	// searchCalls counts Search invocations.
+	searchCalls int
+	// windowed emulates the backend max_result_window: a request with no
+	// OrderBy whose from+size exceeds common.MAX_RESULT_WINDOW is rejected, the
+	// way Elasticsearch rejects from+size beyond index.max_result_window. With a
+	// stable OrderBy set, deep pagination routes to search_after and is allowed.
+	windowed bool
 	// lastDeleteCond captures the most recent DeleteChunks condition.
 	lastDeleteCond map[string]interface{}
 	// deleteConds accumulates every DeleteChunks condition in call order, so a
@@ -48,7 +60,88 @@ type fakeEngine struct {
 
 func (f *fakeEngine) Search(_ context.Context, req *types.SearchRequest) (*types.SearchResult, error) {
 	f.lastSearchReq = req
-	return &types.SearchResult{Chunks: f.searchChunks}, nil
+	f.searchReqs = append(f.searchReqs, req)
+	f.searchCalls++
+	// Honour the subset of filters the production engine applies, so tests can
+	// assert real filtering behaviour (doc_id IN + exists) instead of a raw
+	// pass-through of every canned chunk.
+	chunks := applyEngineFilters(f.searchChunks, req.Filter)
+	if f.windowed {
+		// Faithfully emulate the Elasticsearch/OpenSearch index.max_result_window:
+		// a request whose from+size exceeds the window is rejected. The real
+		// engines only relax this via a stable Sort + search_after; our batch
+		// reader deliberately avoids that path, so a pathological batch simply
+		// fails loudly instead of silently truncating or looping. The rejection
+		// does NOT depend on OrderBy being present, because the engine would
+		// reject the deep from+size regardless once search_after is unavailable.
+		if req.Offset+req.Limit > common.MAX_RESULT_WINDOW {
+			return nil, fmt.Errorf("Result window is too large, from + size must be <= %d", common.MAX_RESULT_WINDOW)
+		}
+		start := req.Offset
+		if start > len(chunks) {
+			start = len(chunks)
+		}
+		end := start + req.Limit
+		if end > len(chunks) {
+			end = len(chunks)
+		}
+		return &types.SearchResult{Chunks: chunks[start:end]}, nil
+	}
+	return &types.SearchResult{Chunks: chunks}, nil
+}
+
+// applyEngineFilters mirrors the production engine's bool.filter handling for the
+// clauses the knowledge_compile reader relies on: doc_id IN (terms) and exists.
+// Other clauses (scope_kwd, type_kwd, slug_kwd, available_int, …) are
+// pass-through. It never mutates the input slice.
+func applyEngineFilters(chunks []map[string]interface{}, filter map[string]interface{}) []map[string]interface{} {
+	if len(filter) == 0 {
+		return chunks
+	}
+	out := chunks
+	if raw, ok := filter["doc_id"]; ok {
+		ids := docIDSet(raw)
+		if len(ids) > 0 {
+			kept := make([]map[string]interface{}, 0, len(out))
+			for _, c := range out {
+				if id, _ := c["doc_id"].(string); ids[id] {
+					kept = append(kept, c)
+				}
+			}
+			out = kept
+		}
+	}
+	if field, ok := filter["exists"].(string); ok && field != "" {
+		kept := make([]map[string]interface{}, 0, len(out))
+		for _, c := range out {
+			if _, present := c[field]; present {
+				kept = append(kept, c)
+			}
+		}
+		out = kept
+	}
+	return out
+}
+
+// docIDSet normalises a doc_id filter value (string, []string, or []interface{} of
+// strings) into a lookup set.
+func docIDSet(raw interface{}) map[string]bool {
+	out := map[string]bool{}
+	switch v := raw.(type) {
+	case string:
+		out[v] = true
+	case []string:
+		for _, s := range v {
+			out[s] = true
+		}
+	case []interface{}:
+		for _, s := range v {
+			if str, ok := s.(string); ok {
+				out[str] = true
+			}
+		}
+	}
+	return out
 }
 
 func (f *fakeEngine) DeleteChunks(_ context.Context, condition map[string]interface{}, _, _ string) (int64, error) {
diff --git a/internal/ingestion/knowledge_compile/pr7_efficiency_test.go b/internal/ingestion/knowledge_compile/pr7_efficiency_test.go
new file mode 100644
index 0000000000..22ec8c7e35
--- /dev/null
+++ b/internal/ingestion/knowledge_compile/pr7_efficiency_test.go
@@ -0,0 +1,273 @@
+//  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+
+package knowledge_compile
+
+import (
+	"context"
+	"reflect"
+	"testing"
+
+	"ragflow/internal/engine/types"
+	kccommon "ragflow/internal/ingestion/component/knowledge_compiler/common"
+)
+
+// ---------------------------------------------------------------------------
+// Change 2: LoadDocProductsByDocs batch reader.
+// ---------------------------------------------------------------------------
+
+func TestLoadDocProductsByDocsGroupsByDoc(t *testing.T) {
+	eng := &fakeEngine{searchChunks: []map[string]interface{}{
+		{"id": "p1", "doc_id": "d1", "compile_kwd": "wiki_page", "available_int": 1, "content_with_weight": "c1"},
+		{"id": "p2", "doc_id": "d2", "compile_kwd": "wiki_page", "available_int": 1, "content_with_weight": "c2"},
+		{"id": "p3", "doc_id": "d1", "compile_kwd": "structure", "available_int": 1, "content_with_weight": "c3"},
+	}}
+	r := engineReader{eng: eng}
+	got, err := r.LoadDocProductsByDocs(context.Background(), "tenant", "kb", []string{"d1", "d2"})
+	if err != nil {
+		t.Fatalf("LoadDocProductsByDocs: %v", err)
+	}
+	filter, ok := eng.lastSearchReq.Filter["doc_id"]
+	if !ok {
+		t.Fatal("missing doc_id filter")
+	}
+	if !reflect.DeepEqual(filter, []interface{}{"d1", "d2"}) {
+		t.Fatalf("doc_id filter = %#v, want []interface{}{\"d1\",\"d2\"}", filter)
+	}
+	if len(got["d1"]) != 2 {
+		t.Fatalf("d1 products = %d, want 2", len(got["d1"]))
+	}
+	if len(got["d2"]) != 1 {
+		t.Fatalf("d2 products = %d, want 1", len(got["d2"]))
+	}
+}
+
+func TestLoadDocProductsByDocsEmptySkipsSearch(t *testing.T) {
+	eng := &fakeEngine{searchChunks: []map[string]interface{}{
+		{"id": "p1", "doc_id": "d1", "compile_kwd": "wiki_page", "available_int": 1, "content_with_weight": "c1"},
+	}}
+	r := engineReader{eng: eng}
+	got, err := r.LoadDocProductsByDocs(context.Background(), "tenant", "kb", nil)
+	if err != nil {
+		t.Fatalf("LoadDocProductsByDocs: %v", err)
+	}
+	if len(got) != 0 {
+		t.Fatalf("empty docIDs must return empty map, got %d entries", len(got))
+	}
+	if eng.searchCalls != 0 {
+		t.Fatalf("empty docIDs must not issue a Search, got %d calls", eng.searchCalls)
+	}
+}
+
+func TestLoadDocProductsByDocsDocWithoutProducts(t *testing.T) {
+	eng := &fakeEngine{searchChunks: []map[string]interface{}{
+		{"id": "p1", "doc_id": "d1", "compile_kwd": "wiki_page", "available_int": 1, "content_with_weight": "c1"},
+	}}
+	r := engineReader{eng: eng}
+	// d2 has no matching rows but is requested: should be present with an empty slice.
+	got, err := r.LoadDocProductsByDocs(context.Background(), "tenant", "kb", []string{"d1", "d2"})
+	if err != nil {
+		t.Fatalf("LoadDocProductsByDocs: %v", err)
+	}
+	if len(got["d1"]) != 1 {
+		t.Fatalf("d1 products = %d, want 1", len(got["d1"]))
+	}
+	if v := got["d2"]; len(v) != 0 {
+		t.Fatalf("d2 must be empty slice, got %d", len(v))
+	}
+}
+
+func TestLoadDocProductsByDocsChunksLargeSet(t *testing.T) {
+	eng := &fakeEngine{searchChunks: []map[string]interface{}{
+		{"id": "p1", "doc_id": "d1", "compile_kwd": "wiki_page", "available_int": 1, "content_with_weight": "c1"},
+	}}
+	r := engineReader{eng: eng}
+	docIDs := make([]string, 0, 1200)
+	for i := 0; i < 1200; i++ {
+		docIDs = append(docIDs, "doc-"+itoa(i))
+	}
+	if _, err := r.LoadDocProductsByDocs(context.Background(), "tenant", "kb", docIDs); err != nil {
+		t.Fatalf("LoadDocProductsByDocs: %v", err)
+	}
+	// 1200 docs at a 500-doc batch must split into 3 searches.
+	if len(eng.searchReqs) != 3 {
+		t.Fatalf("search calls = %d, want 3 (chunked)", len(eng.searchReqs))
+	}
+	wantSizes := []int{500, 500, 200}
+	for i, req := range eng.searchReqs {
+		filter, ok := req.Filter["doc_id"].([]interface{})
+		if !ok {
+			t.Fatalf("req %d missing doc_id []interface{} filter", i)
+		}
+		if len(filter) != wantSizes[i] {
+			t.Fatalf("req %d filter size = %d, want %d", i, len(filter), wantSizes[i])
+		}
+	}
+}
+
+// ---------------------------------------------------------------------------
+// Change 1: buildTopicPagesByKey excludes pages deleted in the same merge step.
+// ---------------------------------------------------------------------------
+
+func TestBuildTopicPagesByKeyExcludesDeleted(t *testing.T) {
+	pages := []kccommon.Product{
+		{ID: "keep", DocID: "kb", Meta: map[string]any{"page_type": "topic", "topic": "a"}},
+		{ID: "del", DocID: "kb", Meta: map[string]any{"page_type": "topic", "topic": "b"}},
+		{ID: "nt", DocID: "kb", Meta: map[string]any{"page_type": "entity", "topic": "c"}},
+	}
+	// mark "del" as a topic page by isTopicPage; isTopicPage reads Meta page_type.
+	excluded := map[string]struct{}{"del": {}}
+	got := buildTopicPagesByKey(pages, excluded)
+	// "keep" topic page survives; "del" (deleted) and "nt" (non-topic) excluded.
+	if _, ok := got["a"]; !ok {
+		t.Fatalf("surviving topic page key \"a\" missing: %v", keysOf(got))
+	}
+	if _, ok := got["b"]; ok {
+		t.Fatalf("deleted topic page key \"b\" must be excluded: %v", keysOf(got))
+	}
+	if _, ok := got["c"]; ok {
+		t.Fatalf("non-topic page key \"c\" must be excluded: %v", keysOf(got))
+	}
+}
+
+// ---------------------------------------------------------------------------
+// Change 3: recoverDocTypesFrom operates on pre-loaded products (batch path).
+// ---------------------------------------------------------------------------
+
+func TestRecoverDocTypesFromEquivalent(t *testing.T) {
+	products := []kccommon.Product{
+		{DocID: "d1", Kind: "structure"},
+		{DocID: "d1", Kind: "tree"},
+		{DocID: "d1", Kind: "structure"}, // duplicate variant, deduped
+	}
+	got, taskTypes, err := recoverDocTypesFrom(products)
+	if err != nil {
+		t.Fatalf("recoverDocTypesFrom: %v", err)
+	}
+	want := []string{string(kccommon.VariantStructure), string(kccommon.VariantTree)}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("variants = %v, want %v", got, want)
+	}
+	if !reflect.DeepEqual(taskTypes, []string{kccommon.TaskTypeGraph, kccommon.TaskTypeTree}) {
+		t.Fatalf("task types = %v, want [Graph Tree]", taskTypes)
+	}
+}
+
+func TestRecoverDocTypesFromUnknownKindHardFails(t *testing.T) {
+	products := []kccommon.Product{
+		{DocID: "d1", Kind: "structure"},
+		{DocID: "d1", Kind: "garbage"},
+	}
+	if _, _, err := recoverDocTypesFrom(products); err == nil {
+		t.Fatal("recoverDocTypesFrom must hard-fail on an unknown authoritative kind")
+	}
+}
+
+func TestRecoverDocTypesFromEmpty(t *testing.T) {
+	got, taskTypes, err := recoverDocTypesFrom(nil)
+	if err != nil {
+		t.Fatalf("recoverDocTypesFrom(nil): %v", err)
+	}
+	if len(got) != 0 || len(taskTypes) != 0 {
+		t.Fatalf("empty products must yield empty variants/taskTypes, got %v/%v", got, taskTypes)
+	}
+}
+
+// ---------------------------------------------------------------------------
+// Change 4: diagnostic construction helpers (gated by IsDebugEnabled at call site).
+// ---------------------------------------------------------------------------
+
+func TestComputeDedupVectorAudit(t *testing.T) {
+	incoming := []kccommon.Product{{Vector: []float32{1}}, {}}
+	candidates := []kccommon.Product{{Vector: []float32{1}}, {Vector: []float32{1}}, {}}
+	inVec, candVec := computeDedupVectorAudit(incoming, candidates)
+	if inVec != 1 || candVec != 2 {
+		t.Fatalf("computeDedupVectorAudit = (%d,%d), want (1,2)", inVec, candVec)
+	}
+}
+
+func TestComputeCandidatesBreakdown(t *testing.T) {
+	candidates := []kccommon.Product{
+		{DocID: "kb", Variant: kccommon.VariantWiki, Meta: map[string]any{"slug": "a"}},
+		{DocID: "kb", Variant: kccommon.VariantWiki, Meta: map[string]any{"slug": "b"}},
+		{DocID: "kb", Variant: kccommon.VariantTree},
+	}
+	byVariant, slugs := computeCandidatesBreakdown(candidates)
+	if byVariant[string(kccommon.VariantWiki)] != 2 || byVariant[string(kccommon.VariantTree)] != 1 {
+		t.Fatalf("byVariant = %v, want wiki=2 tree=1", byVariant)
+	}
+	if len(slugs) != 2 {
+		t.Fatalf("wiki slugs = %d, want 2", len(slugs))
+	}
+}
+
+func TestComputeDocProductsVectorAudit(t *testing.T) {
+	products := []kccommon.Product{{Vector: make([]float32, 4)}, {Vector: make([]float32, 4)}, {}}
+	vecCount, dims := computeDocProductsVectorAudit(products)
+	if vecCount != 2 {
+		t.Fatalf("vecCount = %d, want 2", vecCount)
+	}
+	if dims[4] != 2 {
+		t.Fatalf("dims[4] = %d, want 2", dims[4])
+	}
+}
+
+func TestComputeKNNGroupDumps(t *testing.T) {
+	groups := map[string]*mergeGroup{
+		"g1": {existing: kccommon.Product{ID: "e1"}, candidates: []kccommon.Product{{DocID: "kb"}, {DocID: "kb"}}, score: 0.9},
+	}
+	dumps := computeKNNGroupDumps(groups)
+	if len(dumps) != 1 {
+		t.Fatalf("dumps = %d, want 1", len(dumps))
+	}
+	if dumps[0].Existing != "e1" || len(dumps[0].Candidates) != 2 || dumps[0].Score != 0.9 {
+		t.Fatalf("dump = %+v, want Existing=e1 Candidates=2 Score=0.9", dumps[0])
+	}
+}
+
+// ---------------------------------------------------------------------------
+// helpers
+// ---------------------------------------------------------------------------
+
+func itoa(i int) string {
+	if i == 0 {
+		return "0"
+	}
+	neg := i < 0
+	if neg {
+		i = -i
+	}
+	var b [20]byte
+	pos := len(b)
+	for i > 0 {
+		pos--
+		b[pos] = byte('0' + i%10)
+		i /= 10
+	}
+	if neg {
+		pos--
+		b[pos] = '-'
+	}
+	return string(b[pos:])
+}
+
+func keysOf(m map[string]kccommon.Product) []string {
+	out := make([]string, 0, len(m))
+	for k := range m {
+		out = append(out, k)
+	}
+	return out
+}
+
+var _ = types.SearchRequest{}
diff --git a/internal/ingestion/knowledge_compile/pr7_exists_filter_test.go b/internal/ingestion/knowledge_compile/pr7_exists_filter_test.go
new file mode 100644
index 0000000000..d96619ef3e
--- /dev/null
+++ b/internal/ingestion/knowledge_compile/pr7_exists_filter_test.go
@@ -0,0 +1,113 @@
+//  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+
+package knowledge_compile
+
+import (
+	"context"
+	"fmt"
+	"testing"
+)
+
+// TestLoadDocProductsByDocsExistsFilterSent guards the perf fix for PR #22241:
+// the batched reader must bound its query to compiled rows via an `exists:
+// compile_kwd` clause. Without it the IN-filter also pulls every source chunk
+// (hundreds per document), which both defeats the performance win and overflows
+// the engine's result window on a large KB. This test fails (RED) until the
+// production reader emits the exists clause.
+func TestLoadDocProductsByDocsExistsFilterSent(t *testing.T) {
+	const nDocs = 500
+	const perDoc = 16 // compiled rows only
+	docIDs := make([]string, 0, nDocs)
+	chunks := make([]map[string]interface{}, 0, nDocs*perDoc)
+	for i := 0; i < nDocs; i++ {
+		id := fmt.Sprintf("d%d", i)
+		docIDs = append(docIDs, id)
+		for j := 0; j < perDoc; j++ {
+			chunks = append(chunks, map[string]interface{}{
+				"id":                  fmt.Sprintf("p_%d_%d", i, j),
+				"doc_id":              id,
+				"compile_kwd":         "wiki_page",
+				"available_int":       1,
+				"content_with_weight": "c",
+			})
+		}
+	}
+	eng := &fakeEngine{searchChunks: chunks, windowed: true}
+	r := engineReader{eng: eng}
+	if _, err := r.LoadDocProductsByDocs(context.Background(), "tenant", "kb", docIDs); err != nil {
+		t.Fatalf("LoadDocProductsByDocs: %v", err)
+	}
+	if got, ok := eng.lastSearchReq.Filter["exists"]; !ok || got != "compile_kwd" {
+		t.Fatalf("LoadDocProductsByDocs must send exists:compile_kwd; got Filter=%#v", eng.lastSearchReq.Filter)
+	}
+}
+
+// TestLoadDocProductsByDocsBoundedByExistsAvoidsWindowOverflow is the adversarial
+// guard for the same fix: a 500-document batch mixes compiled rows (which carry
+// compile_kwd) with ordinary source chunks (which do not). Without the exists
+// clause the engine must scan ~20000 rows, so the third page's from+size exceeds
+// the result window and the read errors. With the exists clause the query is
+// bounded to the ~8000 compiled rows, stays within a single window, and returns
+// every compiled product exactly once.
+func TestLoadDocProductsByDocsBoundedByExistsAvoidsWindowOverflow(t *testing.T) {
+	const nDocs = 500
+	const compiledPerDoc = 16
+	const sourcePerDoc = 24 // 500 * 40 = 20000 rows unfiltered (> MAX_RESULT_WINDOW)
+	docIDs := make([]string, 0, nDocs)
+	chunks := make([]map[string]interface{}, 0, nDocs*(compiledPerDoc+sourcePerDoc))
+	for i := 0; i < nDocs; i++ {
+		id := fmt.Sprintf("d%d", i)
+		docIDs = append(docIDs, id)
+		for j := 0; j < compiledPerDoc; j++ {
+			chunks = append(chunks, map[string]interface{}{
+				"id":                  fmt.Sprintf("c_%d_%d", i, j),
+				"doc_id":              id,
+				"compile_kwd":         "wiki_page",
+				"available_int":       1,
+				"content_with_weight": "c",
+			})
+		}
+		for j := 0; j < sourcePerDoc; j++ {
+			chunks = append(chunks, map[string]interface{}{
+				"id":                  fmt.Sprintf("s_%d_%d", i, j),
+				"doc_id":              id,
+				"available_int":       1,
+				"content_with_weight": "source",
+			})
+		}
+	}
+	eng := &fakeEngine{searchChunks: chunks, windowed: true}
+	r := engineReader{eng: eng}
+	got, err := r.LoadDocProductsByDocs(context.Background(), "tenant", "kb", docIDs)
+	if err != nil {
+		t.Fatalf("LoadDocProductsByDocs must stay within the result window via exists:compile_kwd; got err=%v", err)
+	}
+	// Every compiled row must be returned exactly once; source chunks excluded.
+	count := 0
+	seen := map[string]int{}
+	for _, ps := range got {
+		for _, p := range ps {
+			count++
+			seen[p.ID]++
+		}
+	}
+	if count != nDocs*compiledPerDoc {
+		t.Fatalf("recovered products = %d, want %d (silent truncation or source-chunk leak)", count, nDocs*compiledPerDoc)
+	}
+	for id, n := range seen {
+		if n != 1 {
+			t.Fatalf("product %s recovered %d times, want 1 (duplicate across pages)", id, n)
+		}
+	}
+}
diff --git a/internal/ingestion/knowledge_compile/pr7_f1_window_bounds_test.go b/internal/ingestion/knowledge_compile/pr7_f1_window_bounds_test.go
new file mode 100644
index 0000000000..5d2dadaf0e
--- /dev/null
+++ b/internal/ingestion/knowledge_compile/pr7_f1_window_bounds_test.go
@@ -0,0 +1,201 @@
+//  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+
+package knowledge_compile
+
+import (
+	"context"
+	"fmt"
+	"testing"
+)
+
+// buildCompiledOnlyChunks returns nDocs documents each with compiledPerDoc
+// compiled rows (compile_kwd set, no source chunks). This isolates the F1
+// failure mode: the doc_id IN batch aggregates more compiled rows than the
+// engine result window, independent of the source-chunk inflation that the
+// exists:compile_kwd filter already fixes.
+func buildCompiledOnlyChunks(nDocs, compiledPerDoc int) ([]string, []map[string]interface{}) {
+	docIDs := make([]string, 0, nDocs)
+	chunks := make([]map[string]interface{}, 0, nDocs*compiledPerDoc)
+	for i := 0; i < nDocs; i++ {
+		id := fmt.Sprintf("d%d", i)
+		docIDs = append(docIDs, id)
+		for j := 0; j < compiledPerDoc; j++ {
+			chunks = append(chunks, map[string]interface{}{
+				"id":                  fmt.Sprintf("c_%d_%d", i, j),
+				"doc_id":              id,
+				"compile_kwd":         "wiki_page",
+				"available_int":       1,
+				"content_with_weight": "c",
+			})
+		}
+	}
+	return docIDs, chunks
+}
+
+// TestLoadDocProductsByDocsCompiledRowsExceedWindow is the adversarial guard for
+// F1: a 500-document batch whose COMPILED rows alone (no source chunks) exceed
+// MAX_RESULT_WINDOW (10000) must not hard-fail. The exists:compile_kwd filter
+// already excludes source chunks, but a product-dense batch can still aggregate
+// more than 10k compiled rows; plain from/size cannot page past the window, so
+// the reader must fall back to per-document reads for that sub-batch.
+func TestLoadDocProductsByDocsCompiledRowsExceedWindow(t *testing.T) {
+	const nDocs = 500
+	const compiledPerDoc = 30 // 500*30 = 15000 compiled rows > MAX_RESULT_WINDOW(10000)
+	docIDs, chunks := buildCompiledOnlyChunks(nDocs, compiledPerDoc)
+	eng := &fakeEngine{searchChunks: chunks, windowed: true}
+	r := engineReader{eng: eng}
+	got, err := r.LoadDocProductsByDocs(context.Background(), "tenant", "kb", docIDs)
+	if err != nil {
+		t.Fatalf("compiled-only batch exceeding window must fall back to per-doc reads, not error: %v", err)
+	}
+	// Fallback must have engaged (batched path alone would error or need >2 calls).
+	if eng.searchCalls <= 2 {
+		t.Fatalf("expected fallback to per-doc reads (more than 2 Search calls), got %d", eng.searchCalls)
+	}
+	// Every compiled product returned exactly once, grouped by doc.
+	count := 0
+	seen := map[string]int{}
+	for _, ps := range got {
+		for _, p := range ps {
+			count++
+			seen[p.ID]++
+		}
+	}
+	if count != nDocs*compiledPerDoc {
+		t.Fatalf("recovered products = %d, want %d (silent truncation past window)", count, nDocs*compiledPerDoc)
+	}
+	for id, n := range seen {
+		if n != 1 {
+			t.Fatalf("product %s recovered %d times, want 1 (duplicate across pages/fallback)", id, n)
+		}
+	}
+}
+
+// TestLoadDocProductsByDocsExactlyAtWindowFallsBack is the off-by-one guard:
+// a batch whose compiled rows land exactly on MAX_RESULT_WINDOW (10000) still
+// triggers a 3rd page request (offset 10000) that plain from/size rejects, so
+// the fallback must engage here too.
+func TestLoadDocProductsByDocsExactlyAtWindowFallsBack(t *testing.T) {
+	const nDocs = 500
+	const compiledPerDoc = 20 // 500*20 = 10000 exactly
+	docIDs, chunks := buildCompiledOnlyChunks(nDocs, compiledPerDoc)
+	eng := &fakeEngine{searchChunks: chunks, windowed: true}
+	r := engineReader{eng: eng}
+	got, err := r.LoadDocProductsByDocs(context.Background(), "tenant", "kb", docIDs)
+	if err != nil {
+		t.Fatalf("exactly-at-window batch must fall back to per-doc reads, not error: %v", err)
+	}
+	if eng.searchCalls <= 2 {
+		t.Fatalf("expected fallback to per-doc reads (more than 2 Search calls), got %d", eng.searchCalls)
+	}
+	count := 0
+	seen := map[string]int{}
+	for _, ps := range got {
+		for _, p := range ps {
+			count++
+			seen[p.ID]++
+		}
+	}
+	if count != nDocs*compiledPerDoc {
+		t.Fatalf("recovered products = %d, want %d", count, nDocs*compiledPerDoc)
+	}
+	for id, n := range seen {
+		if n != 1 {
+			t.Fatalf("product %s recovered %d times, want 1", id, n)
+		}
+	}
+}
+
+// TestLoadDocProductsByDocsUnderWindowStaysBatched guards against regressing the
+// common path: a batch comfortably under the window must keep using the batched
+// IN read (2 Search calls for 8000 rows paged at 5000), never silently falling
+// back to one query per document.
+func TestLoadDocProductsByDocsUnderWindowStaysBatched(t *testing.T) {
+	const nDocs = 500
+	const compiledPerDoc = 16 // 500*16 = 8000 < MAX_RESULT_WINDOW(10000)
+	docIDs, chunks := buildCompiledOnlyChunks(nDocs, compiledPerDoc)
+	eng := &fakeEngine{searchChunks: chunks, windowed: true}
+	r := engineReader{eng: eng}
+	got, err := r.LoadDocProductsByDocs(context.Background(), "tenant", "kb", docIDs)
+	if err != nil {
+		t.Fatalf("under-window batch must not error: %v", err)
+	}
+	if eng.searchCalls != 2 {
+		t.Fatalf("expected batched path (2 Search calls), got %d (regressed to per-doc?)", eng.searchCalls)
+	}
+	count := 0
+	for _, ps := range got {
+		count += len(ps)
+	}
+	if count != nDocs*compiledPerDoc {
+		t.Fatalf("recovered products = %d, want %d", count, nDocs*compiledPerDoc)
+	}
+}
+
+// TestLoadDocProductsByDocsMixedOverflowSubBatches guards the per-sub-batch
+// scoping of the fallback: across a single call, the first 500-doc sub-batch is
+// product-dense (overflows -> falls back to per-doc) while the second 500-doc
+// sub-batch is comfortably under the window (stays batched). The overflow of one
+// sub-batch must not disable batching for the next, nor corrupt its results.
+func TestLoadDocProductsByDocsMixedOverflowSubBatches(t *testing.T) {
+	const densePerDoc = 30  // first 500 docs -> 15000 compiled rows > window
+	const sparsePerDoc = 16 // next 500 docs -> 8000 compiled rows < window
+	const nDocs = 1000
+	docIDs := make([]string, 0, nDocs)
+	chunks := make([]map[string]interface{}, 0, nDocs*densePerDoc)
+	for i := 0; i < nDocs; i++ {
+		id := fmt.Sprintf("d%d", i)
+		docIDs = append(docIDs, id)
+		perDoc := sparsePerDoc
+		if i < 500 {
+			perDoc = densePerDoc
+		}
+		for j := 0; j < perDoc; j++ {
+			chunks = append(chunks, map[string]interface{}{
+				"id":                  fmt.Sprintf("c_%d_%d", i, j),
+				"doc_id":              id,
+				"compile_kwd":         "wiki_page",
+				"available_int":       1,
+				"content_with_weight": "c",
+			})
+		}
+	}
+	eng := &fakeEngine{searchChunks: chunks, windowed: true}
+	r := engineReader{eng: eng}
+	got, err := r.LoadDocProductsByDocs(context.Background(), "tenant", "kb", docIDs)
+	if err != nil {
+		t.Fatalf("mixed sub-batches must not error: %v", err)
+	}
+	// 502 calls for the dense (overflow) sub-batch + 2 for the sparse sub-batch.
+	if eng.searchCalls != 504 {
+		t.Fatalf("expected 504 Search calls (502 fallback + 2 batched), got %d", eng.searchCalls)
+	}
+	count := 0
+	seen := map[string]int{}
+	for _, ps := range got {
+		for _, p := range ps {
+			count++
+			seen[p.ID]++
+		}
+	}
+	want := 500*densePerDoc + 500*sparsePerDoc
+	if count != want {
+		t.Fatalf("recovered products = %d, want %d", count, want)
+	}
+	for id, n := range seen {
+		if n != 1 {
+			t.Fatalf("product %s recovered %d times, want 1", id, n)
+		}
+	}
+}
diff --git a/internal/ingestion/knowledge_compile/pr7_window_fix_test.go b/internal/ingestion/knowledge_compile/pr7_window_fix_test.go
new file mode 100644
index 0000000000..2aef88050f
--- /dev/null
+++ b/internal/ingestion/knowledge_compile/pr7_window_fix_test.go
@@ -0,0 +1,164 @@
+//  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
+//
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+
+package knowledge_compile
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+	"testing"
+
+	kccommon "ragflow/internal/ingestion/component/knowledge_compiler/common"
+)
+
+// TestLoadDocProductsByDocsSendsNoSearchAfterOrderBy guards the fix for PR
+// #22241 review findings: the batched reader must NOT rely on OrderBy: Asc("id")
+// to drive search_after deep pagination. On OpenSearch parseOrderByExpr drops the
+// "id" field (no sort emitted), so useSearchAfter opens with a nil cursor and the
+// read silently re-reads the first page (truncation + duplicates); on Elasticsearch
+// 8.x the id-> _id translation is rejected by default (indices.id_field_data off),
+// so the whole read fails. A 500-document batch never approaches the result window
+// in practice, so plain from/size paging is correct and safe. The reader must
+// therefore send NO OrderBy.
+func TestLoadDocProductsByDocsSendsNoSearchAfterOrderBy(t *testing.T) {
+	eng := &fakeEngine{searchChunks: []map[string]interface{}{
+		{"id": "p1", "doc_id": "d1", "compile_kwd": "wiki_page", "available_int": 1, "content_with_weight": "c1"},
+	}}
+	r := engineReader{eng: eng}
+	if _, err := r.LoadDocProductsByDocs(context.Background(), "tenant", "kb", []string{"d1"}); err != nil {
+		t.Fatalf("LoadDocProductsByDocs: %v", err)
+	}
+	if eng.lastSearchReq == nil {
+		t.Fatalf("expected a SearchRequest to be captured")
+	}
+	if eng.lastSearchReq.OrderBy != nil && len(eng.lastSearchReq.OrderBy.Fields) > 0 {
+		t.Fatalf("LoadDocProductsByDocs must not send an OrderBy (would drive broken search_after); got %#v", eng.lastSearchReq.OrderBy)
+	}
+}
+
+// TestLoadDocProductsByDocsReadsAllRowsWithinWindow is the happy-path guard: a
+// batch whose aggregated rows stay under the backend max_result_window must return
+// every product exactly once, paged with plain from/size (no search_after).
+func TestLoadDocProductsByDocsReadsAllRowsWithinWindow(t *testing.T) {
+	const nDocs = 500
+	const perDoc = 16 // 500 * 16 = 8000 rows (< MAX_RESULT_WINDOW 10000)
+	docIDs := make([]string, 0, nDocs)
+	chunks := make([]map[string]interface{}, 0, nDocs*perDoc)
+	for i := 0; i < nDocs; i++ {
+		id := fmt.Sprintf("d%d", i)
+		docIDs = append(docIDs, id)
+		for j := 0; j < perDoc; j++ {
+			chunks = append(chunks, map[string]interface{}{
+				"id":                  fmt.Sprintf("p_%d_%d", i, j),
+				"doc_id":              id,
+				"compile_kwd":         "wiki_page",
+				"available_int":       1,
+				"content_with_weight": "c",
+			})
+		}
+	}
+	eng := &fakeEngine{searchChunks: chunks, windowed: true}
+	r := engineReader{eng: eng}
+	got, err := r.LoadDocProductsByDocs(context.Background(), "tenant", "kb", docIDs)
+	if err != nil {
+		t.Fatalf("LoadDocProductsByDocs: %v", err)
+	}
+	count := 0
+	for _, ps := range got {
+		count += len(ps)
+	}
+	if count != nDocs*perDoc {
+		t.Fatalf("recovered products = %d, want %d (silent truncation past the result window)", count, nDocs*perDoc)
+	}
+	// no duplicates: each (doc, product id) must appear once.
+	seen := map[string]int{}
+	for _, ps := range got {
+		for _, p := range ps {
+			seen[p.ID]++
+		}
+	}
+	for id, n := range seen {
+		if n != 1 {
+			t.Fatalf("product %s recovered %d times, want 1 (duplicate across pages)", id, n)
+		}
+	}
+}
+
+// TestRecoverDocVariantsBatchChunksBounded guards review finding #1:
+// RebuildDataset must not hold the entire KB's compiled products (including
+// vectors) in memory at once. recoverDocVariantsBatch walks docs in
+// docProductsBatchSize chunks, so each LoadDocProductsByDocs call stays bounded
+// and the in-flight product set is released after each chunk.
+func TestRecoverDocVariantsBatchChunksBounded(t *testing.T) {
+	const nDocs = 1200
+	docs := make([]string, 0, nDocs)
+	products := make([]kccommon.Product, 0, nDocs)
+	for i := 0; i < nDocs; i++ {
+		id := fmt.Sprintf("d%d", i)
+		docs = append(docs, id)
+		products = append(products, kccommon.Product{DocID: id, Kind: "structure"})
+	}
+	fr := &fakeReader{products: products}
+	c := &Consumer{reader: fr}
+	got, err := c.recoverDocVariantsBatch(context.Background(), "t", "kb", docs)
+	if err != nil {
+		t.Fatalf("recoverDocVariantsBatch: %v", err)
+	}
+	if len(got) != nDocs {
+		t.Fatalf("recovered docs = %d, want %d", len(got), nDocs)
+	}
+	for _, id := range docs {
+		vr, ok := got[id]
+		if !ok {
+			t.Fatalf("missing recovery for %s", id)
+		}
+		if !reflect.DeepEqual(vr.variants, []string{string(kccommon.VariantStructure)}) {
+			t.Fatalf("%s variants = %v, want [structure]", id, vr.variants)
+		}
+	}
+	// Memory-bounding: every batch read must stay within docProductsBatchSize.
+	for i, sz := range fr.batchSizes {
+		if sz > docProductsBatchSize {
+			t.Fatalf("batch %d size = %d, exceeds docProductsBatchSize %d (unbounded read)", i, sz, docProductsBatchSize)
+		}
+	}
+	// 1200 docs chunked at 500 => exactly 3 calls (500 + 500 + 200).
+	if len(fr.batchSizes) != 3 {
+		t.Fatalf("batch calls = %d, want 3 (chunked into docProductsBatchSize)", len(fr.batchSizes))
+	}
+	if fr.batchSizes[0] != docProductsBatchSize || fr.batchSizes[1] != docProductsBatchSize || fr.batchSizes[2] != 200 {
+		t.Fatalf("batch sizes = %v, want [500 500 200]", fr.batchSizes)
+	}
+}
+
+// TestRecoverDocVariantsBatchDocWithoutProducts ensures a document with no
+// compiled products yields empty variants (the caller skips it) rather than an
+// error.
+func TestRecoverDocVariantsBatchDocWithoutProducts(t *testing.T) {
+	fr := &fakeReader{products: []kccommon.Product{
+		{DocID: "d1", Kind: "structure"},
+	}}
+	c := &Consumer{reader: fr}
+	got, err := c.recoverDocVariantsBatch(context.Background(), "t", "kb", []string{"d1", "d2"})
+	if err != nil {
+		t.Fatalf("recoverDocVariantsBatch: %v", err)
+	}
+	if vr, ok := got["d2"]; !ok || len(vr.variants) != 0 {
+		t.Fatalf("d2 must recover empty variants, got %#v", vr)
+	}
+	if !reflect.DeepEqual(got["d1"].variants, []string{string(kccommon.VariantStructure)}) {
+		t.Fatalf("d1 variants = %v, want [structure]", got["d1"].variants)
+	}
+}
diff --git a/internal/ingestion/knowledge_compile/reader.go b/internal/ingestion/knowledge_compile/reader.go
index 940190e1e0..90ee1752a9 100644
--- a/internal/ingestion/knowledge_compile/reader.go
+++ b/internal/ingestion/knowledge_compile/reader.go
@@ -18,6 +18,7 @@ package knowledge_compile
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"strconv"
 	"strings"
@@ -47,6 +48,10 @@ type Reader interface {
 	// document (doc_id == source_doc). Bounded by one document, never the whole
 	// KB.
 	LoadDocProducts(ctx context.Context, tenant, kb, docID string) ([]kccommon.Product, error)
+	// LoadDocProductsByDocs returns the per-document compiled rows for many
+	// documents in one query, grouped by doc_id. It is the batch form of
+	// LoadDocProducts used to avoid one query per document.
+	LoadDocProductsByDocs(ctx context.Context, tenant, kb string, docIDs []string) (map[string][]kccommon.Product, error)
 
 	// SearchSimilar runs a dense (KNN) search over the existing merged rows of
 	// the given variant and returns the single most-similar row whose score is
@@ -152,6 +157,30 @@ var wikiSelectFields = []string{
 // LoadDocProducts pages until the engine returns fewer than a full page.
 const loadDocProductsLimit = 5000
 
+// pageThrough issues req against eng, paging with plain from/size, and invokes
+// visit for every page's chunks. It stops after the final (short) page so a
+// result set larger than one page is read completely without silent
+// truncation or looping. req.Offset is advanced on each iteration; callers must
+// not set it beforehand. req.Limit is left to the caller (typically
+// loadDocProductsLimit).
+func pageThrough(ctx context.Context, eng engine.DocEngine, req *types.SearchRequest, limit int, visit func(chunks []map[string]interface{}) error) error {
+	for offset := 0; ; offset += limit {
+		req.Offset = offset
+		res, err := eng.Search(ctx, req)
+		if err != nil {
+			return err
+		}
+		if res != nil {
+			if err := visit(res.Chunks); err != nil {
+				return err
+			}
+		}
+		if len(res.Chunks) < limit {
+			return nil
+		}
+	}
+}
+
 // LoadDocProducts returns the per-document compiled rows for a single document.
 // It is bounded to one document, so the consumer never loads the whole KB. The
 // results are paged so a document with more than loadDocProductsLimit rows is
@@ -162,20 +191,15 @@ func (r engineReader) LoadDocProducts(ctx context.Context, tenant, kb, docID str
 	}
 	eng := r.eng
 	var out []kccommon.Product
-	offset := 0
-	for {
-		res, err := eng.Search(ctx, &types.SearchRequest{
-			IndexNames:   []string{fmt.Sprintf("ragflow_%s", tenant)},
-			KbIDs:        []string{kb},
-			Filter:       map[string]interface{}{"doc_id": docID},
-			SelectFields: append(append([]string(nil), compiledSelectFields...), wikiSelectFields...),
-			Limit:        loadDocProductsLimit,
-			Offset:       offset,
-		})
-		if err != nil {
-			return nil, err
-		}
-		for _, c := range res.Chunks {
+	req := &types.SearchRequest{
+		IndexNames:   []string{fmt.Sprintf("ragflow_%s", tenant)},
+		KbIDs:        []string{kb},
+		Filter:       map[string]interface{}{"doc_id": docID},
+		SelectFields: append(append([]string(nil), compiledSelectFields...), wikiSelectFields...),
+		Limit:        loadDocProductsLimit,
+	}
+	if err := pageThrough(ctx, eng, req, loadDocProductsLimit, func(chunks []map[string]interface{}) error {
+		for _, c := range chunks {
 			// Only compiled products carry compile_kwd; skip ordinary source chunks.
 			if _, ok := c["compile_kwd"]; !ok || types.IsNavigationRow(c) {
 				continue
@@ -190,32 +214,155 @@ func (r engineReader) LoadDocProducts(ctx context.Context, tenant, kb, docID str
 				out = append(out, p)
 			}
 		}
-		if len(res.Chunks) < loadDocProductsLimit {
-			break
-		}
-		offset += loadDocProductsLimit
+		return nil
+	}); err != nil {
+		return nil, err
 	}
 	// Diagnostics: count how many loaded per-doc products carry an embedding
 	// and report the (deduped) vector dimensions. If this shows 0/empty while
 	// per-doc rows in ES do have q_<dim>_vec, VectorFromChunkMap is failing to
-	// restore the vector and the merged rows will end up embedding-less.
-	vecCount := 0
-	dims := map[int]int{}
-	for _, p := range out {
-		if dim := len(p.Vector); dim > 0 {
-			vecCount++
-			dims[dim]++
+	// restore the vector and the merged rows will end up embedding-less. Gated to
+	// debug: the map construction below allocates even in quiet production.
+	if common.IsDebugEnabled() {
+		vecCount, dims := computeDocProductsVectorAudit(out)
+		common.Info("knowledge_compile: LoadDocProducts vector audit",
+			zap.String("kb_id", kb),
+			zap.String("doc_id", docID),
+			zap.Int("products", len(out)),
+			zap.Int("with_vector", vecCount),
+			zap.Any("vector_dims", dims))
+	}
+	return out, nil
+}
+
+// docProductsBatchSize bounds how many doc_ids are sent in a single IN filter so a
+// batch read over a large KB does not build an unbounded query.
+const docProductsBatchSize = 500
+
+// LoadDocProductsByDocs returns the per-document compiled products for many
+// documents in one query (doc_id IN [...]) instead of one query per document.
+// Results are grouped by doc_id; documents with no compiled rows map to an empty
+// (non-nil) slice so callers can distinguish "no products" from "missing".
+//
+// Each doc_id IN sub-batch is read with a single bounded query. Because plain
+// from/size cannot page past the engine result window (MAX_RESULT_WINDOW), a
+// sub-batch whose aggregated compiled rows would force a page beyond the window
+// falls back to one bounded per-document read per document (the pre-PR behavior)
+// instead of erroring — a product-dense large KB must not lose or mis-read
+// merged state during a rebuild.
+func (r engineReader) LoadDocProductsByDocs(ctx context.Context, tenant, kb string, docIDs []string) (map[string][]kccommon.Product, error) {
+	if r.eng == nil {
+		return nil, errEngineNotConfigured
+	}
+	if len(docIDs) == 0 {
+		return map[string][]kccommon.Product{}, nil
+	}
+	out := make(map[string][]kccommon.Product, len(docIDs))
+	for _, docID := range docIDs {
+		out[docID] = nil // ensure every requested doc has an entry
+	}
+	fields := append(append([]string(nil), compiledSelectFields...), wikiSelectFields...)
+	for start := 0; start < len(docIDs); start += docProductsBatchSize {
+		end := start + docProductsBatchSize
+		if end > len(docIDs) {
+			end = len(docIDs)
+		}
+		batch := docIDs[start:end]
+		local, overflow, err := r.loadDocProductsBatch(ctx, tenant, kb, batch, fields)
+		if err != nil {
+			return nil, err
+		}
+		if overflow {
+			// The sub-batch's compiled rows exceed the engine result window, so a
+			// single doc_id IN read cannot page past it without erroring. Fall
+			// back to one bounded per-document read per document: each document
+			// is bounded to itself and never aggregates to the window, so the
+			// read stays correct for product-dense batches.
+			for _, docID := range batch {
+				ps, perr := r.LoadDocProducts(ctx, tenant, kb, docID)
+				if perr != nil {
+					return nil, perr
+				}
+				out[docID] = ps
+			}
+			continue
+		}
+		for docID, ps := range local {
+			out[docID] = ps
 		}
 	}
-	common.Info("knowledge_compile: LoadDocProducts vector audit",
-		zap.String("kb_id", kb),
-		zap.String("doc_id", docID),
-		zap.Int("products", len(out)),
-		zap.Int("with_vector", vecCount),
-		zap.Any("vector_dims", dims))
 	return out, nil
 }
 
+// errBatchOverflow is returned by loadDocProductsBatch's paging visitor to signal
+// that the next page would exceed the engine result window; the caller falls
+// back to per-document reads instead of letting the engine reject the query.
+var errBatchOverflow = errors.New("knowledge_compile: batch read reached result window")
+
+// loadDocProductsBatch reads the compiled products for a slice of doc_ids with a
+// single doc_id IN query, paging with plain from/size. It returns the products
+// grouped by doc_id. If the aggregate result set is large enough that the next
+// page would require offset+limit > MAX_RESULT_WINDOW (which the engine rejects
+// for plain from/size), it stops paging early and reports overflow=true so the
+// caller can fall back to per-document reads rather than erroring.
+func (r engineReader) loadDocProductsBatch(ctx context.Context, tenant, kb string, batch []string, fields []string) (map[string][]kccommon.Product, bool, error) {
+	local := make(map[string][]kccommon.Product, len(batch))
+	req := &types.SearchRequest{
+		IndexNames:   []string{fmt.Sprintf("ragflow_%s", tenant)},
+		KbIDs:        []string{kb},
+		Filter:       map[string]interface{}{"doc_id": docIDInterfaceSlice(batch), "exists": "compile_kwd"},
+		SelectFields: fields,
+		Limit:        loadDocProductsLimit,
+	}
+	overflow := false
+	err := pageThrough(ctx, r.eng, req, loadDocProductsLimit, func(chunks []map[string]interface{}) error {
+		// The next page would land at offset+limit, and that fetch needs
+		// (offset+limit)+limit <= MAX_RESULT_WINDOW. If it would not, stop now
+		// and let the caller fall back to per-document reads for this batch.
+		// A next page (offset+limit) is only fetched when this page is full, and
+		// only then could a deep page exceed the engine result window. Signal
+		// overflow only in that case, so a short final page never triggers the
+		// per-document fallback.
+		if len(chunks) == loadDocProductsLimit && req.Offset+2*loadDocProductsLimit > common.MAX_RESULT_WINDOW {
+			overflow = true
+			return errBatchOverflow
+		}
+		for _, c := range chunks {
+			// Only compiled products carry compile_kwd; skip ordinary source chunks.
+			if _, ok := c["compile_kwd"]; !ok || types.IsNavigationRow(c) {
+				continue
+			}
+			rowVariant, verr := KwdToVariant(asString(c["compile_kwd"]))
+			if verr != nil {
+				continue
+			}
+			if p, ok := productFromChunkMap(c, tenant, rowVariant); ok {
+				if docID, _ := c["doc_id"].(string); docID != "" {
+					local[docID] = append(local[docID], p)
+				}
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		if errors.Is(err, errBatchOverflow) {
+			return local, true, nil
+		}
+		return nil, false, err
+	}
+	return local, overflow, nil
+}
+
+// docIDInterfaceSlice converts a string doc_id list into the []interface{} form
+// the engine's IN filter expects.
+func docIDInterfaceSlice(docIDs []string) []interface{} {
+	out := make([]interface{}, len(docIDs))
+	for i, d := range docIDs {
+		out[i] = d
+	}
+	return out
+}
+
 func (r engineReader) LoadMergedProduct(ctx context.Context, tenant, kb, id string) (kccommon.Product, error) {
 	if r.eng == nil {
 		return kccommon.Product{}, errEngineNotConfigured
@@ -248,30 +395,22 @@ func (r engineReader) LoadMergedWikiPages(ctx context.Context, tenant, kb string
 		return nil, errEngineNotConfigured
 	}
 	eng := r.eng
-	filter := map[string]interface{}{"available_int": 1, "scope_kwd": "dataset", "type_kwd": compileKwdWikiPage}
 	var pages []kccommon.Product
-	for offset := 0; ; offset += loadDocProductsLimit {
-		res, err := eng.Search(ctx, &types.SearchRequest{
-			IndexNames: []string{fmt.Sprintf("ragflow_%s", tenant)}, KbIDs: []string{kb},
-			Limit: loadDocProductsLimit, Offset: offset,
-			OrderBy:      (&types.OrderByExpr{}).Asc("id"),
-			SelectFields: append(append([]string(nil), compiledSelectFields...), wikiSelectFields...),
-			Filter:       filter,
-		})
-		if err != nil {
-			return nil, err
-		}
-		if res == nil || len(res.Chunks) == 0 {
-			break
-		}
-		for _, row := range res.Chunks {
+	req := &types.SearchRequest{
+		IndexNames: []string{fmt.Sprintf("ragflow_%s", tenant)}, KbIDs: []string{kb},
+		Limit:        loadDocProductsLimit,
+		SelectFields: append(append([]string(nil), compiledSelectFields...), wikiSelectFields...),
+		Filter:       map[string]interface{}{"available_int": 1, "scope_kwd": "dataset", "type_kwd": compileKwdWikiPage},
+	}
+	if err := pageThrough(ctx, eng, req, loadDocProductsLimit, func(chunks []map[string]interface{}) error {
+		for _, row := range chunks {
 			if product, ok := productFromChunkMap(row, tenant, kccommon.VariantWiki); ok && kccommon.MetaString(product.Meta, "kind") == "page" {
 				pages = append(pages, product)
 			}
 		}
-		if len(res.Chunks) < loadDocProductsLimit {
-			break
-		}
+		return nil
+	}); err != nil {
+		return nil, err
 	}
 	return pages, nil
 }
@@ -300,28 +439,21 @@ func (r engineReader) LoadDocumentWikiPagesBySlugs(ctx context.Context, tenant,
 		filter["doc_id"] = enabledIDs
 	}
 	var pages []kccommon.Product
-	for offset := 0; ; offset += loadDocProductsLimit {
-		res, err := eng.Search(ctx, &types.SearchRequest{
-			IndexNames: []string{fmt.Sprintf("ragflow_%s", tenant)}, KbIDs: []string{kb},
-			Limit: loadDocProductsLimit, Offset: offset,
-			OrderBy:      (&types.OrderByExpr{}).Asc("id"),
-			SelectFields: append(append([]string(nil), compiledSelectFields...), wikiSelectFields...),
-			Filter:       filter,
-		})
-		if err != nil {
-			return nil, err
-		}
-		if res == nil || len(res.Chunks) == 0 {
-			break
-		}
-		for _, row := range res.Chunks {
+	req := &types.SearchRequest{
+		IndexNames: []string{fmt.Sprintf("ragflow_%s", tenant)}, KbIDs: []string{kb},
+		Limit:        loadDocProductsLimit,
+		SelectFields: append(append([]string(nil), compiledSelectFields...), wikiSelectFields...),
+		Filter:       filter,
+	}
+	if err := pageThrough(ctx, eng, req, loadDocProductsLimit, func(chunks []map[string]interface{}) error {
+		for _, row := range chunks {
 			if product, ok := productFromChunkMap(row, tenant, kccommon.VariantWiki); ok && kccommon.MetaString(product.Meta, "kind") == "page" {
 				pages = append(pages, product)
 			}
 		}
-		if len(res.Chunks) < loadDocProductsLimit {
-			break
-		}
+		return nil
+	}); err != nil {
+		return nil, err
 	}
 	return pages, nil
 }
diff --git a/internal/ingestion/knowledge_compile/rebuild_variants_test.go b/internal/ingestion/knowledge_compile/rebuild_variants_test.go
index 639719e055..26d656cdc6 100644
--- a/internal/ingestion/knowledge_compile/rebuild_variants_test.go
+++ b/internal/ingestion/knowledge_compile/rebuild_variants_test.go
@@ -8,70 +8,50 @@ import (
 	kccommon "ragflow/internal/ingestion/component/knowledge_compiler/common"
 )
 
-// fakeReader is a Reader double that returns a canned product set for
-// recoverDocTypes tests.
+// fakeReader is a Reader double that returns a canned product set for the
+// recoverDocVariantsBatch tests.
 type fakeReader struct {
 	products []kccommon.Product
+	// batchSizes records the doc_id slice length passed to each
+	// LoadDocProductsByDocs call, so chunking tests can assert bounded batches.
+	batchSizes []int
 }
 
 func (f *fakeReader) LoadDocProducts(context.Context, string, string, string) ([]kccommon.Product, error) {
 	return f.products, nil
 }
 
+func (f *fakeReader) LoadDocProductsByDocs(_ context.Context, _, _ string, docIDs []string) (map[string][]kccommon.Product, error) {
+	f.batchSizes = append(f.batchSizes, len(docIDs))
+	out := make(map[string][]kccommon.Product, len(docIDs))
+	for _, docID := range docIDs {
+		out[docID] = nil
+	}
+	for _, p := range f.products {
+		out[p.DocID] = append(out[p.DocID], p)
+	}
+	return out, nil
+}
+
 func (f *fakeReader) SearchSimilar(context.Context, string, string, kccommon.Variant, []float64, int, float64) (kccommon.Product, float64, error) {
 	return kccommon.Product{}, 0, nil
 }
 
-// TestRecoverDocTypes_AuthoritativeKind covers B1a/O2a: the authoritative
-// Product.Kind (compilation_template_kind_kwd) is mapped through KindToVariant;
-// results are sorted/deduped.
-func TestRecoverDocVariants_AuthoritativeKind(t *testing.T) {
-	c := &Consumer{reader: &fakeReader{products: []kccommon.Product{
-		{DocID: "d1", Kind: "structure"},
-		{DocID: "d1", Kind: "tree"},
-		// duplicate variant, deduped
-		{DocID: "d1", Kind: "structure"},
-	}}}
-	got, taskTypes, err := c.recoverDocTypes(context.Background(), "t1", "kb1", "d1")
-	if err != nil {
-		t.Fatalf("recoverDocTypes error: %v", err)
-	}
-	want := []string{string(kccommon.VariantStructure), string(kccommon.VariantTree)}
-	if !reflect.DeepEqual(got, want) {
-		t.Fatalf("recoverDocTypes variants = %v, want %v", got, want)
-	}
-	if !reflect.DeepEqual(taskTypes, []string{kccommon.TaskTypeGraph, kccommon.TaskTypeTree}) {
-		t.Fatalf("recoverDocTypes task types = %v, want [Graph Tree]", taskTypes)
-	}
-}
-
-// TestRecoverDocTypes_UnknownKindHardFails covers O2a: a whitelist-out
-// authoritative kind aborts recovery (returns an error) so the rebuild does not
-// proceed with an incomplete variant set.
-func TestRecoverDocVariants_UnknownKindHardFails(t *testing.T) {
-	c := &Consumer{reader: &fakeReader{products: []kccommon.Product{
-		{DocID: "d1", Kind: "structure"},
-		{DocID: "d1", Kind: "garbage"},
-	}}}
-	if _, _, err := c.recoverDocTypes(context.Background(), "t1", "kb1", "d1"); err == nil {
-		t.Fatal("recoverDocTypes must hard-fail on an unknown authoritative kind (O2a)")
-	}
-}
-
-// TestRecoverDocTypes_FallbackVariant covers B1a: a product without an
-// authoritative kind falls back to its reverse-mapped variant.
-func TestRecoverDocVariants_FallbackVariant(t *testing.T) {
-	c := &Consumer{reader: &fakeReader{products: []kccommon.Product{
+// TestRecoverDocTypesFromFallbackVariant covers B1a: a product without an
+// authoritative kind falls back to its reverse-mapped variant. This is the
+// branch the deleted recoverDocTypes wrapper used to exercise; it now lives on
+// the shared recoverDocTypesFrom helper used by the rebuild batch path.
+func TestRecoverDocTypesFromFallbackVariant(t *testing.T) {
+	got, taskTypes, err := recoverDocTypesFrom([]kccommon.Product{
 		{DocID: "d1", Variant: kccommon.VariantWiki},
-	}}}
-	got, taskTypes, err := c.recoverDocTypes(context.Background(), "t1", "kb1", "d1")
+	})
 	if err != nil {
-		t.Fatalf("recoverDocTypes error: %v", err)
+		t.Fatalf("recoverDocTypesFrom error: %v", err)
 	}
 	if len(got) != 1 || got[0] != string(kccommon.VariantWiki) {
-		t.Fatalf("recoverDocTypes fallback = %v, want [wiki]", got)
+		t.Fatalf("recoverDocTypesFrom fallback = %v, want [wiki]", got)
 	}
 	if !reflect.DeepEqual(taskTypes, []string{kccommon.TaskTypeWiki}) {
-		t.Fatalf("recoverDocTypes fallback task types = %v, want [Wiki]", taskTypes)
+		t.Fatalf("recoverDocTypesFrom fallback task types = %v, want [Wiki]", taskTypes)
 	}
 }
diff --git a/internal/ingestion/knowledge_compile/wiki_contribution.go b/internal/ingestion/knowledge_compile/wiki_contribution.go
index 2f29a53e49..6e1fc78d24 100644
--- a/internal/ingestion/knowledge_compile/wiki_contribution.go
+++ b/internal/ingestion/knowledge_compile/wiki_contribution.go
@@ -305,18 +305,28 @@ func (c *Consumer) prepareWikiContributionDiff(ctx context.Context, tenantID, da
 		affectedSlugs: map[string]struct{}{},
 	}
 	completedByDoc := make(map[string]BacklogEntry, len(completed))
+	completedDocIDs := make([]string, 0, len(completed))
+	seenDoc := make(map[string]struct{})
 	for _, entry := range completed {
-		completedByDoc[entry.DocID] = entry
-		products, err := c.reader.LoadDocProducts(ctx, tenantID, datasetID, entry.DocID)
-		if err != nil {
-			return wikiContributionDiffResult{}, err
+		completedByDoc[entry.DocID] = entry // last entry per doc wins, as before
+		if _, ok := seenDoc[entry.DocID]; !ok {
+			seenDoc[entry.DocID] = struct{}{}
+			completedDocIDs = append(completedDocIDs, entry.DocID)
 		}
-		result.productsByDoc[entry.DocID] = products
+	}
+	// One query for every completed document instead of one query per document.
+	productsByDocAll, err := c.reader.LoadDocProductsByDocs(ctx, tenantID, datasetID, completedDocIDs)
+	if err != nil {
+		return wikiContributionDiffResult{}, err
+	}
+	for docID, entry := range completedByDoc {
+		products := productsByDocAll[docID]
+		result.productsByDoc[docID] = products
 		wikiProducts := products
 		if len(entry.Variants) > 0 && !variantsContain(entry.Variants, "wiki") {
 			wikiProducts = nil
 		}
-		result.currentByDoc[entry.DocID] = buildWikiDocumentContribution(entry.DocID, wikiProducts)
+		result.currentByDoc[docID] = buildWikiDocumentContribution(docID, wikiProducts)
 	}
 
 	allDocIDs := make([]string, 0, len(completed)+len(deleted))