diff --git "a/data/2.PostgreSQL\344\270\255\351\230\266/2.\346\234\215\345\212\241\347\253\257\347\274\226\347\250\213/7.DDL/config.json" "b/data/2.PostgreSQL\344\270\255\351\230\266/2.\346\234\215\345\212\241\347\253\257\347\274\226\347\250\213/7.DDL/config.json"
index 4831a2bf47658609a3a75e138d552b686b49abcd..2c27754d4f64ff8f9d47eaa9d172576c8f93d739 100644
--- "a/data/2.PostgreSQL\344\270\255\351\230\266/2.\346\234\215\345\212\241\347\253\257\347\274\226\347\250\213/7.DDL/config.json"
+++ "b/data/2.PostgreSQL\344\270\255\351\230\266/2.\346\234\215\345\212\241\347\253\257\347\274\226\347\250\213/7.DDL/config.json"
@@ -4,6 +4,6 @@
   "children": [],
   "export": [
     "create_table.json",
-    "anylze.json"
+    "analyze.json"
   ]
 }
\ No newline at end of file
diff --git "a/data/3.PostgreSQL\351\253\230\351\230\266/2.\351\253\230\347\272\247\346\225\260\346\215\256\347\261\273\345\236\213/1.\345\207\240\344\275\225\347\261\273\345\236\213\345\222\214GIS/config.json" "b/data/3.PostgreSQL\351\253\230\351\230\266/2.\351\253\230\347\272\247\346\225\260\346\215\256\347\261\273\345\236\213/1.\345\207\240\344\275\225\347\261\273\345\236\213\345\222\214GIS/config.json"
index b99d8b54997bf034899150b1cce368a47da36d3a..9a79271c48aaf466ae4c9d9602be04ec2541c51b 100644
--- "a/data/3.PostgreSQL\351\253\230\351\230\266/2.\351\253\230\347\272\247\346\225\260\346\215\256\347\261\273\345\236\213/1.\345\207\240\344\275\225\347\261\273\345\236\213\345\222\214GIS/config.json"
+++ "b/data/3.PostgreSQL\351\253\230\351\230\266/2.\351\253\230\347\272\247\346\225\260\346\215\256\347\261\273\345\236\213/1.\345\207\240\344\275\225\347\261\273\345\236\213\345\222\214GIS/config.json"
@@ -1,6 +1,6 @@
 {
   "node_id": "pg-3bbe12c0a19d4cb7a61dc0a20624ed89",
-  "keywords": [],
+  "keywords": ["gis", "地理信息"],
   "children": [],
-  "export": []
+  "export": ["gis.json"]
 }
\ No newline at end of file
diff --git "a/data/3.PostgreSQL\351\253\230\351\230\266/2.\351\253\230\347\272\247\346\225\260\346\215\256\347\261\273\345\236\213/1.\345\207\240\344\275\225\347\261\273\345\236\213\345\222\214GIS/gis.json" "b/data/3.PostgreSQL\351\253\230\351\230\266/2.\351\253\230\347\272\247\346\225\260\346\215\256\347\261\273\345\236\213/1.\345\207\240\344\275\225\347\261\273\345\236\213\345\222\214GIS/gis.json"
new file mode 100644
index 0000000000000000000000000000000000000000..a8279b3148ff2a3845971dfdb90b71b71056ecb2
--- /dev/null
+++ "b/data/3.PostgreSQL\351\253\230\351\230\266/2.\351\253\230\347\272\247\346\225\260\346\215\256\347\261\273\345\236\213/1.\345\207\240\344\275\225\347\261\273\345\236\213\345\222\214GIS/gis.json"
@@ -0,0 +1,7 @@
+{
+  "type": "code_options",
+  "author": "刘鑫",
+  "source": "gis.md",
+  "notebook_enable": false,
+  "exercise_id": "88b033cd97c642ef9900e5e091e335ff"
+}
\ No newline at end of file
diff --git "a/data/3.PostgreSQL\351\253\230\351\230\266/2.\351\253\230\347\272\247\346\225\260\346\215\256\347\261\273\345\236\213/1.\345\207\240\344\275\225\347\261\273\345\236\213\345\222\214GIS/gis.md" "b/data/3.PostgreSQL\351\253\230\351\230\266/2.\351\253\230\347\272\247\346\225\260\346\215\256\347\261\273\345\236\213/1.\345\207\240\344\275\225\347\261\273\345\236\213\345\222\214GIS/gis.md"
new file mode 100644
index 0000000000000000000000000000000000000000..3d54b4a6af201646b00604bb8506f7076bd857ad
--- /dev/null
+++ "b/data/3.PostgreSQL\351\253\230\351\230\266/2.\351\253\230\347\272\247\346\225\260\346\215\256\347\261\273\345\236\213/1.\345\207\240\344\275\225\347\261\273\345\236\213\345\222\214GIS/gis.md"
@@ -0,0 +1,66 @@
+# 邻近查找
+
+我们有一个简化的表结构如下：
+
+```postgresql
+create table city
+(
+    id   serial8,
+    city text,
+    poi  point
+);
+create index idx_tbl_point on city using gist (poi) with (buffering = on);
+```
+
+要查找给定的点位于哪个城市，或者离哪个城市最近，应该是下列哪一项？
+
+## 答案
+
+```postgresql
+select city, poi <-> point($1, $2) dist
+from city
+where poi <-> point($1, $2) < 100
+order by poi <-> point($1, $2)
+limit 1;
+```
+
+## 选项
+
+### A
+
+```postgresql
+select city, poi <-> point($1, $2) dist
+from city
+where poi <-> point($1, $2) < 100
+order by poi <-> point($1, $2) desc
+limit 1;
+```
+
+### B
+
+```postgresql
+select *, poi <-> point($1, $2) dist
+from city
+where poi <-> point($1, $2) < 100
+limit 1;
+```
+
+### C
+
+```postgresql
+select *, poi - point($1, $2) dist
+from city
+where poi - point($1, $2) < 100
+order by poi - point($1, $2)
+limit 1;
+```
+
+### D
+
+```postgresql
+select *, abs(poi - point($1, $2)) dist
+from city
+where abs(poi - point($1, $2)) < 100
+order by abs(poi - point($1, $2))
+limit 1;
+```
\ No newline at end of file
diff --git a/data/tree.json b/data/tree.json
index 0919968dab870f481e6caae74275b7600dbdfc8f..669c8cf432ce965ef56be649aa4c295d5829edf6 100644
--- a/data/tree.json
+++ b/data/tree.json
@@ -211,7 +211,11 @@
                   {
                     "DDL": {
                       "node_id": "pg-0378bcd60ccd4dfebcfead92abbdd673",
-                      "keywords": [],
+                      "keywords": [
+                        "创建表",
+                        "授权",
+                        "ddl"
+                      ],
                       "children": []
                     }
                   }
@@ -263,7 +267,10 @@
                   {
                     "几何类型和GIS": {
                       "node_id": "pg-3bbe12c0a19d4cb7a61dc0a20624ed89",
-                      "keywords": [],
+                      "keywords": [
+                        "gis",
+                        "地理信息"
+                      ],
                       "children": []
                     }
                   },