diff --git a/packages/elastic/index.ts b/packages/elastic/index.ts
index 31aa77683..d33f89b55 100644
--- a/packages/elastic/index.ts
+++ b/packages/elastic/index.ts
@@ -40,16 +40,19 @@ global.Hydro.lib.problemSearch = async (domainId, q, opts) => {
     });
     let hits = res.hits.hits.map((i) => i._id);
     if (!opts.skip) {
-        const pdoc = await ProblemModel.get(domainId, +q || q, ProblemModel.PROJECTION_LIST);
+        let pdoc = await ProblemModel.get(domainId, +q || q, ProblemModel.PROJECTION_LIST);
         if (pdoc) {
             hits = hits.filter((i) => i !== `${pdoc.domainId}/${pdoc.docId}`);
             hits.unshift(`${pdoc.domainId}/${pdoc.docId}`);
+        } else if (/^P\d+$/.test(q)) {
+            pdoc = await ProblemModel.get(domainId, +q.substring(1), ProblemModel.PROJECTION_LIST);
+            if (pdoc) hits.unshift(`${pdoc.domainId}/${pdoc.docId}`);
         }
     }
     return {
         countRelation: typeof res.hits.total === 'number' ? 'eq' : res.hits.total.relation,
         total: typeof res.hits.total === 'number' ? res.hits.total : res.hits.total.value,
-        hits,
+        hits: Array.from(new Set(hits)),
     };
 };
 
diff --git a/packages/hydrooj/src/handler/problem.ts b/packages/hydrooj/src/handler/problem.ts
index a43b26f92..16408f24c 100644
--- a/packages/hydrooj/src/handler/problem.ts
+++ b/packages/hydrooj/src/handler/problem.ts
@@ -1,7 +1,7 @@
 import AdmZip from 'adm-zip';
 import { readFile, statSync } from 'fs-extra';
 import {
-    escapeRegExp, flattenDeep, intersection, pick, uniqBy,
+    escapeRegExp, flattenDeep, intersection, pick,
 } from 'lodash';
 import { Filter, ObjectId } from 'mongodb';
 import { nanoid } from 'nanoid';
@@ -34,7 +34,6 @@ import user from '../model/user';
 import {
     Handler, param, post, query, route, Types,
 } from '../service/server';
-import { buildProjection } from '../utils';
 import { ContestDetailBaseHandler } from './contest';
 
 export const parseCategory = (value: string) => value.replace(/，/g, ',').split(',').map((e) => e.trim());
@@ -53,16 +52,21 @@ function buildQuery(udoc: User) {
 
 const defaultSearch = async (domainId: string, q: string, options?: ProblemSearchOptions) => {
     const escaped = escapeRegExp(q.toLowerCase());
+    const projection: (keyof ProblemDoc)[] = ['domainId', 'docId', 'pid'];
     const $regex = new RegExp(q.length >= 2 ? escaped : `\\A${escaped}`, 'gmi');
     const filter = { $or: [{ pid: { $regex } }, { title: { $regex } }, { tag: q }] };
-    const pdocs = await problem.getMulti(domainId, filter, ['domainId', 'docId', 'pid'])
+    const pdocs = await problem.getMulti(domainId, filter, projection)
         .skip(options.skip || 0).limit(options.limit || system.get('pagination.problem')).toArray();
     if (!options.skip) {
-        const pdoc = await problem.get(domainId, +q || q, ['domainId', 'docId', 'pid', 'title']);
+        let pdoc = await problem.get(domainId, Number.isSafeInteger(+q) ? +q : q, projection);
         if (pdoc) pdocs.unshift(pdoc);
+        else if (/^P\d+$/.test(q)) {
+            pdoc = await problem.get(domainId, +q.substring(1), projection);
+            if (pdoc) pdocs.unshift(pdoc);
+        }
     }
     return {
-        hits: pdocs.map((i) => `${i.domainId}/${i.docId}`),
+        hits: Array.from(new Set(pdocs.map((i) => `${i.domainId}/${i.docId}`))),
         total: Math.max(pdocs.length, await problem.count(domainId, filter)),
         countRelation: 'eq',
     };
@@ -95,7 +99,8 @@ export class ProblemMainHandler extends Handler {
     @param('q', Types.Content, true)
     @param('limit', Types.PositiveInt, true)
     @param('pjax', Types.Boolean)
-    async get(domainId: string, page = 1, q = '', limit: number, pjax = false) {
+    @param('quick', Types.Boolean)
+    async get(domainId: string, page = 1, q = '', limit: number, pjax = false, quick = false) {
         this.response.template = 'problem_main.html';
         if (!limit || limit > this.ctx.setting.get('pagination.problem') || page > 1) limit = this.ctx.setting.get('pagination.problem');
         this.queryContext.query = buildQuery(this.user);
@@ -137,7 +142,11 @@ export class ProblemMainHandler extends Handler {
         // eslint-disable-next-line prefer-const
         let [pdocs, ppcount, pcount] = this.queryContext.fail
             ? [[], 0, 0]
-            : await problem.list(domainId, query, sort.length ? 1 : page, limit, undefined, this.user._id);
+            : await problem.list(
+                domainId, query, sort.length ? 1 : page, limit,
+                quick ? ['title', 'pid', 'domainId', 'docId'] : undefined,
+                this.user._id,
+            );
         if (total) {
             pcount = total;
             ppcount = Math.ceil(total / limit);
@@ -995,28 +1004,6 @@ export class ProblemCreateHandler extends Handler {
     }
 }
 
-export class ProblemPrefixListHandler extends Handler {
-    @param('prefix', Types.Name)
-    async get(domainId: string, prefix: string) {
-        const projection = ['domainId', 'docId', 'pid', 'title', 'hidden'] as const;
-        const [pdocs, pdoc, apdoc] = await Promise.all([
-            problem.getPrefixList(domainId, prefix),
-            problem.get(domainId, Number.isSafeInteger(+prefix) ? +prefix : prefix, projection),
-            /^P\d+$/.test(prefix) ? problem.get(domainId, +prefix.substring(1), projection) : Promise.resolve(null),
-        ]);
-        if (apdoc) pdocs.unshift(apdoc);
-        if (pdoc) pdocs.unshift(pdoc);
-        if (pdocs.length < 20) {
-            const search = global.Hydro.lib.problemSearch || defaultSearch;
-            const result = await search(domainId, prefix, { limit: 20 - pdocs.length });
-            const docs = await problem.getMulti(domainId, { docId: { $in: result.hits.map((i) => +i.split('/')[1]) } })
-                .project<ProblemDoc>(buildProjection(projection)).toArray();
-            pdocs.push(...docs);
-        }
-        this.response.body = uniqBy(pdocs, 'docId');
-    }
-}
-
 export async function apply(ctx: Context) {
     ctx.Route('problem_main', '/p', ProblemMainHandler, PERM.PERM_VIEW_PROBLEM);
     ctx.Route('problem_random', '/problem/random', ProblemRandomHandler, PERM.PERM_VIEW_PROBLEM);
@@ -1033,7 +1020,6 @@ export async function apply(ctx: Context) {
     ctx.Route('problem_solution_reply_raw', '/p/:pid/solution/:psid/:psrid/raw', ProblemSolutionRawHandler, PERM.PERM_VIEW_PROBLEM);
     ctx.Route('problem_statistics', '/p/:pid/stat', ProblemStatisticsHandler, PERM.PERM_VIEW_PROBLEM);
     ctx.Route('problem_create', '/problem/create', ProblemCreateHandler, PERM.PERM_CREATE_PROBLEM);
-    ctx.Route('problem_prefix_list', '/problem/list', ProblemPrefixListHandler, PERM.PERM_VIEW_PROBLEM);
     ctx.inject(['api'], ({ api }) => {
         api.value('FileInfo', [
             ['_id', 'String!'],
diff --git a/packages/hydrooj/src/model/problem.ts b/packages/hydrooj/src/model/problem.ts
index 55e0d1357..2401995ab 100644
--- a/packages/hydrooj/src/model/problem.ts
+++ b/packages/hydrooj/src/model/problem.ts
@@ -162,7 +162,8 @@ export class ProblemModel {
         if (Number.isSafeInteger(+pid)) pid = +pid;
         const res = typeof pid === 'number'
             ? await document.get(domainId, document.TYPE_PROBLEM, pid, projection)
-            : (await document.getMulti(domainId, document.TYPE_PROBLEM, { sort: sortable(pid), pid }).toArray())[0];
+            : (await document.getMulti(domainId, document.TYPE_PROBLEM, { sort: sortable(pid), pid })
+                .project(buildProjection(projection)).limit(1).toArray())[0];
         if (!res) return null;
         try {
             if (!rawConfig) res.config = await parseConfig(res.config);
diff --git a/packages/ui-default/components/autocomplete/components/ProblemSelectAutoComplete.tsx b/packages/ui-default/components/autocomplete/components/ProblemSelectAutoComplete.tsx
index e0c1b26de..64468884a 100644
--- a/packages/ui-default/components/autocomplete/components/ProblemSelectAutoComplete.tsx
+++ b/packages/ui-default/components/autocomplete/components/ProblemSelectAutoComplete.tsx
@@ -8,7 +8,10 @@ const ProblemSelectAutoComplete = forwardRef<AutoCompleteHandle<ProblemDoc>, Aut
   <AutoComplete<ProblemDoc>
     ref={ref as any}
     cacheKey={`problem-${UiContext.domainId}`}
-    queryItems={(query) => request.get(`/d/${UiContext.domainId}/problem/list`, { prefix: query })}
+    queryItems={async (query) => {
+      const { pdocs } = await request.get(`/d/${UiContext.domainId}/p`, { q: query, quick: true });
+      return pdocs;
+    }}
     fetchItems={(ids) => api(gql`
       problems(ids: ${ids.map((i) => +i)}) {
         docId