From 3a770f7dd30f41d7174c852e2dc8c91e895bd287 Mon Sep 17 00:00:00 2001
From: "cai.zhang" <cai.zhang@zilliz.com>
Date: Thu, 29 Sep 2022 09:32:55 +0800
Subject: [PATCH] Suport to create flat index (#19398)

Signed-off-by: cai.zhang <cai.zhang@zilliz.com>

Signed-off-by: cai.zhang <cai.zhang@zilliz.com>
---
 internal/indexcoord/const.go         | 1 +
 internal/indexcoord/index_builder.go | 6 +++---
 internal/indexcoord/task.go          | 2 +-
 internal/indexcoord/util.go          | 2 +-
 internal/proxy/task.go               | 1 +
 5 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/internal/indexcoord/const.go b/internal/indexcoord/const.go
index 5def064b8e..d6c37abed3 100644
--- a/internal/indexcoord/const.go
+++ b/internal/indexcoord/const.go
@@ -21,6 +21,7 @@ const (
 	IndexAddTaskName    = "IndexAddTask"
 	CreateIndexTaskName = "CreateIndexTask"
 
+	flatIndex    = "FLAT"
 	diskAnnIndex = "DISKANN"
 	invalidIndex = "invalid"
 )
diff --git a/internal/indexcoord/index_builder.go b/internal/indexcoord/index_builder.go
index 503ad95b8c..1eb3aa5477 100644
--- a/internal/indexcoord/index_builder.go
+++ b/internal/indexcoord/index_builder.go
@@ -212,8 +212,9 @@ func (ib *indexBuilder) process(buildID UniqueID) bool {
 			deleteFunc(buildID)
 			return true
 		}
-		if meta.NumRows < Params.IndexCoordCfg.MinSegmentNumRowsToEnableIndex {
-			log.Ctx(ib.ctx).Debug("segment num rows is too few, no need to build index", zap.Int64("buildID", buildID),
+		indexParams := ib.meta.GetIndexParams(meta.CollectionID, meta.IndexID)
+		if getIndexType(indexParams) == flatIndex || meta.NumRows < Params.IndexCoordCfg.MinSegmentNumRowsToEnableIndex {
+			log.Ctx(ib.ctx).Debug("segment does not need index really", zap.Int64("buildID", buildID),
 				zap.Int64("segID", meta.SegmentID), zap.Int64("num rows", meta.NumRows))
 			if err := ib.meta.FinishTask(&indexpb.IndexTaskInfo{
 				BuildID:        buildID,
@@ -271,7 +272,6 @@ func (ib *indexBuilder) process(buildID UniqueID) bool {
 		}
 
 		typeParams := ib.meta.GetTypeParams(meta.CollectionID, meta.IndexID)
-		indexParams := ib.meta.GetIndexParams(meta.CollectionID, meta.IndexID)
 
 		var storageConfig *indexpb.StorageConfig
 		if Params.CommonCfg.StorageType == "local" {
diff --git a/internal/indexcoord/task.go b/internal/indexcoord/task.go
index 04dc381ac1..5ee2b0d013 100644
--- a/internal/indexcoord/task.go
+++ b/internal/indexcoord/task.go
@@ -127,7 +127,7 @@ func (cit *CreateIndexTask) PreExecute(ctx context.Context) error {
 	log.Info("IndexCoord CreateIndexTask PreExecute", zap.Int64("collectionID", cit.req.CollectionID),
 		zap.Int64("fieldID", cit.req.FieldID), zap.String("indexName", cit.req.IndexName))
 	// TODO: check index type is disk index.
-	if GetIndexType(cit.req.GetIndexParams()) == diskAnnIndex && !cit.indexCoordClient.nodeManager.ClientSupportDisk() {
+	if getIndexType(cit.req.GetIndexParams()) == diskAnnIndex && !cit.indexCoordClient.nodeManager.ClientSupportDisk() {
 		return errors.New("all IndexNodes do not support disk indexes, please verify")
 	}
 	return nil
diff --git a/internal/indexcoord/util.go b/internal/indexcoord/util.go
index ac6a07ea1c..3ccffabe1a 100644
--- a/internal/indexcoord/util.go
+++ b/internal/indexcoord/util.go
@@ -74,7 +74,7 @@ func buildHandoffKey(collID, partID, segID UniqueID) string {
 	return fmt.Sprintf("%s/%d/%d/%d", util.HandoffSegmentPrefix, collID, partID, segID)
 }
 
-func GetIndexType(indexParams []*commonpb.KeyValuePair) string {
+func getIndexType(indexParams []*commonpb.KeyValuePair) string {
 	for _, param := range indexParams {
 		if param.Key == "index_type" {
 			return param.Value
diff --git a/internal/proxy/task.go b/internal/proxy/task.go
index c46990d57e..6d6e575b09 100644
--- a/internal/proxy/task.go
+++ b/internal/proxy/task.go
@@ -1191,6 +1191,7 @@ func parseIndexParams(m []*commonpb.KeyValuePair) (map[string]string, error) {
 	}
 	_, exist := indexParams["index_type"] // TODO(dragondriver): change `index_type` to const variable
 	if !exist {
+		//return nil, errors.New("there is no index_type in index params")
 		indexParams["index_type"] = indexparamcheck.IndexFaissIvfPQ // IVF_PQ is the default index type
 	}
 	return indexParams, nil