From bf5fb3cd99e725d2ca0d3a9fb374d6bbf29ce6d4 Mon Sep 17 00:00:00 2001
From: wgcn <1026688210@qq.com>
Date: Mon, 31 Oct 2022 13:25:35 +0800
Subject: [PATCH] improve show collection (#20124)

Signed-off-by: wgcn <1026688210@qq.com>
---
 internal/rootcoord/meta_table.go | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/internal/rootcoord/meta_table.go b/internal/rootcoord/meta_table.go
index 50e0f3d2fe..bdf9b964ad 100644
--- a/internal/rootcoord/meta_table.go
+++ b/internal/rootcoord/meta_table.go
@@ -355,6 +355,10 @@ func (mt *MetaTable) ListCollections(ctx context.Context, ts Timestamp) ([]*mode
 	mt.ddLock.RLock()
 	defer mt.ddLock.RUnlock()
 
+	if isMaxTs(ts) {
+		return mt.listCollectionFromCache()
+	}
+
 	// list collections should always be loaded from catalog.
 	ctx1 := contextutil.WithTenantID(ctx, Params.CommonCfg.ClusterName)
 	colls, err := mt.catalog.ListCollections(ctx1, ts)
@@ -370,6 +374,16 @@ func (mt *MetaTable) ListCollections(ctx context.Context, ts Timestamp) ([]*mode
 	return onlineCollections, nil
 }
 
+func (mt *MetaTable) listCollectionFromCache() ([]*model.Collection, error) {
+	collectionFromCache := make([]*model.Collection, 0)
+	for _, meta := range mt.collID2Meta {
+		if meta.Available() {
+			collectionFromCache = append(collectionFromCache, meta)
+		}
+	}
+	return collectionFromCache, nil
+}
+
 func (mt *MetaTable) ListAbnormalCollections(ctx context.Context, ts Timestamp) ([]*model.Collection, error) {
 	mt.ddLock.RLock()
 	defer mt.ddLock.RUnlock()