upgrade to performance

data/2.MySQL中阶/3.聚合和分组/3.最小值/min.md

@@ -43,5 +43,5 @@ select dept, min(salary) from employee;
 ### D
 
 ```mysql
-select sum(total) from orders having deal and unit_price > 1000;
+select dept, min(total) from employee;
 ```
\ No newline at end of file

data/2.MySQL中阶/3.聚合和分组/5. 平均值/avg.json

+{
+  "type": "code_options",
+  "author": "ccat",
+  "source": "avg.md",
+  "notebook_enable": false,
+  "exercise_id": "c6ff6b73f6844327b71b6b0630fedcaa"
+}
\ No newline at end of file

data/2.MySQL中阶/3.聚合和分组/5. 平均值/avg.md

+# 平均值练习
+
+Joe 想要得到 employee 表
+
+```mysql
+create table employee
+(
+    id     serial primary key,
+    name   varchar(256),
+    dept   varchar(256),
+    salary decimal(12, 4)
+);
+```
+
+中每个部门的平均工资信息，这条查询应该怎么写？
+
+## 答案
+
+```mysql
+select dept, avg(salary) from employee group by dept;
+```
+
+## 选项
+
+### A
+
+```mysql
+select dept, avg(salary) from employee;
+```
+
+### B
+
+```mysql
+select dept, avg(salary) from employee;
+```
+
+### C
+
+```mysql
+select dept, avg(salary) from employee;
+```
+
+### D
+
+```mysql
+select dept, avg(salary) from employee ;
+```
\ No newline at end of file

data/2.MySQL中阶/3.聚合和分组/5. 平均值/config.json

@@ -2,11 +2,10 @@
   "node_id": "mysql-11462fccf9d24d17a372d5c60af90f54",
   "keywords": [],
   "children": [],
-  "export": [],
-  "keywords_must": [
-    ["mysql", "平均值"],
-    ["mysql", "avg"]
+  "export": [
+    "avg.json"
   ],
+  "keywords_must": [],
   "keywords_forbid": [],
   "group": 0
 }
\ No newline at end of file

data/3.MySQL高阶/10.应用程序优化/1.复用数据库连接/config.json

-{
-  "node_id": "mysql-769c096b229842239e2ba2f8d1c768d3",
-  "keywords": ["连接复用", "连接池"],
-  "children": [],
-  "export": [],
-  "keywords_must": [],
-  "keywords_forbid": [],
-  "group": 0
-}
\ No newline at end of file

data/3.MySQL高阶/10.应用程序优化/2.减少数据访问/config.json

-{
-  "node_id": "mysql-d7b339f2b2434e3fbd3721b7cd1abc1a",
-  "keywords": ["performance", "application", "io"],
-  "children": [],
-  "export": [],
-  "keywords_must": [],
-  "keywords_forbid": [],
-  "group": 0
-}
\ No newline at end of file

data/3.MySQL高阶/10.应用程序优化/3.开启查询缓存/config.json

-{
-  "node_id": "mysql-8973ee6a0cb045b7bcf623b4e5757baa",
-  "keywords": [],
-  "children": [],
-  "export": [],
-  "keywords_must": [],
-  "keywords_forbid": [],
-  "group": 0
-}
\ No newline at end of file

data/3.MySQL高阶/10.应用程序优化/4.使用外部缓存/config.json

-{
-  "node_id": "mysql-7f86d4e58a514a44bce09a19595f9cab",
-  "keywords": [],
-  "children": [],
-  "export": [],
-  "keywords_must": [],
-  "keywords_forbid": [],
-  "group": 0
-}
\ No newline at end of file

data/3.MySQL高阶/10.应用程序优化/5.分布式 MySQL 架构/config.json

-{
-  "node_id": "mysql-402ec368b74f4c33b33c812e9f762d3a",
-  "keywords": [],
-  "children": [],
-  "export": [],
-  "keywords_must": [],
-  "keywords_forbid": [],
-  "group": 0
-}
\ No newline at end of file

data/3.MySQL高阶/10.应用程序优化/config.json

-{
-  "node_id": "mysql-288d4606c1ae4f49a0ab79212bc0ff2b",
-  "keywords": [],
-  "keywords_must": [],
-  "keywords_forbid": [],
-  "group": 2
-}
\ No newline at end of file

data/3.MySQL高阶/5.设计优化/4.反范式设计/config.json

@@ -2,7 +2,9 @@
   "node_id": "mysql-3e4c837b471c454c90bfbc32445f2780",
   "keywords": [],
   "children": [],
-  "export": [],
+  "export": [
+    "slack.json"
+  ],
   "keywords_must": [],
   "keywords_forbid": [],
   "group": 0

data/3.MySQL高阶/5.设计优化/4.反范式设计/slack.json

+{
+  "type": "code_options",
+  "author": "ccat",
+  "source": "slack.md",
+  "notebook_enable": false,
+  "exercise_id": "d62e33f550494f849f87b62acdcf9d0a"
+}
\ No newline at end of file

data/3.MySQL高阶/5.设计优化/4.反范式设计/slack.md

+# 反范式设计
+
+反范式优化的主要动机和思路是：
+
+1. 通过适当增加冗余字段，减少连接查询的次数和复杂度
+2. 对于经常发生的聚合计算，如果对实时正确性要求不高，可以缓存中间结果，减少实时的聚合计算压力
+3. 用适度的写冗余，换取读操作的大幅优化
+4. 适当的放宽索引，可以优化局限于少数字段的查询性能
+
+## 答案
+
+全部都是
+
+## 选项
+
+### A
+
+全部都不对
+
+### B
+
+```
+1, 2, 3
+```
+
+### C
+
+```
+2, 3, 4
+```
+
+### D
+
+```
+2, 3
+```
+
+### E
+
+```
+3, 4
+```
\ No newline at end of file

data/3.MySQL高阶/5.设计优化/5.清理重复索引和冗余索引/config.json

-{
-  "node_id": "mysql-06bc5338054a40fc90b24333ee2b9125",
-  "keywords": [],
-  "children": [],
-  "export": [],
-  "keywords_must": [],
-  "keywords_forbid": [],
-  "group": 0
-}
\ No newline at end of file

data/3.MySQL高阶/5.设计优化/8.检查数据表/config.json → data/3.MySQL高阶/5.设计优化/7.检查数据表/config.json

 {
   "node_id": "mysql-fbcc654d6a86452aa349d2ed6003adb6",
-  "keywords": [],
+  "keywords": ["show profile"],
   "children": [],
   "export": [],
   "keywords_must": [],

data/3.MySQL高阶/8.写优化/1.插入优化/bulk_insert.json

+{
+  "type": "code_options",
+  "author": null,
+  "source": "bulk_insert.md",
+  "notebook_enable": false,
+  "exercise_id": "936ee1ecbd4a4b9aa795fa537e24f659"
+}
\ No newline at end of file

data/3.MySQL高阶/8.写优化/1.插入优化/bulk_insert.md

+# 批量写入
+
+Joe 需要为数据组准备一个离线数据库，这个数据库的数据量很大。
+下面这些措施中有哪些可以帮助 Joe 更快的写入这些数据？
+
+1. 使用`ALTER TABLE t_table_name DISABLE KEYS;`禁用索引，完成工作后用`ALTER TABLE t_table_name ENABLE KEYS;`启用索引
+2. 使用`SET UNIQUE_CHECKS = 0;`禁用唯一性检查，完成工作后用`SET UNIQUE_CHECKS = 1;`恢复唯一性检查
+3. 使用`SET foreign_key_checks = 0;`禁用外键检查，完成工作后`SET foreign_key_checks = 1;`恢复外键检查
+4. 使用`insert values(...),(...),(...)...`批量插入数据
+5. 使用`LOAD DATA INFILE ‘data_file_path’ INTO TABLE table_name;`批量导入数据
+6. 对 InnoDB 表使用 `SET autocommit = 0;` 禁用自动事务，完成工作后用 `SET autocommit = 1;`
+
+## 答案
+
+全部都对
+
+## 选项
+
+### A
+
+```
+1, 2, 3, 4, 5
+```
+
+### B
+
+```
+2, 3, 4, 5
+```
+
+### C
+
+```
+2, 3, 4, 6
+```
+
+### D
+
+```
+1, 2, 3, 4
+```
+
+### D
+
+```
+3, 4, 5, 6
+```
+
+### E
+
+```
+3, 4
+```
\ No newline at end of file

data/3.MySQL高阶/8.写优化/1.插入优化/config.json

@@ -2,7 +2,9 @@
   "node_id": "mysql-4e93793f51a24f0eb00f7824ecc8929b",
   "keywords": [],
   "children": [],
-  "export": [],
+  "export": [
+    "bulk_insert.json"
+  ],
   "keywords_must": [],
   "keywords_forbid": [],
   "group": 0

data/3.MySQL高阶/8.写优化/2.删除优化/config.json

 {
   "node_id": "mysql-ff4222264013437da2214ff77ca92961",
-  "keywords": [],
+  "keywords": ["delete", "performance", "优化", "删除"],
   "children": [],
-  "export": [],
+  "export": [
+    "performance_delete.json"
+  ],
   "keywords_must": [],
   "keywords_forbid": [],
   "group": 0

data/3.MySQL高阶/8.写优化/2.删除优化/performance_delete.json

+{
+  "type": "code_options",
+  "author": null,
+  "source": "performance_delete.md",
+  "notebook_enable": false,
+  "exercise_id": "105bda06ce03418aaad1422b61767cb6"
+}
\ No newline at end of file

data/3.MySQL高阶/8.写优化/2.删除优化/performance_delete.md

+# 快速删除
+
+Joe 需要删除数据分析库中 orders 表的数据，orders按时间分区，因为是分析部门离线使用，不需要考虑并发，下列哪些操作可以更快的删除这些数据？
+
+1. 使用 `truncate from orders`;
+2. 可以执行 `ALTER TABLE orders DROP PARTITION partition_name;` 删除指定分区
+3. 去掉唯一约束然后 `delete from orders where 1=1`
+4. 使用可写游标，一次一万行滚动删除
+5. `drop table orders` 删除后重建
+
+## 答案
+
+```
+1, 2, 5
+```
+
+## 选项
+
+### A
+
+全部选项都可以
+
+### B
+
+```
+1, 2, 3, 4
+```
+
+### C
+
+```
+3, 4
+```
+
+### D
+
+```
+2, 3
+```
+
+### E
+
+```
+2, 3， 4
+```
\ No newline at end of file

data/3.MySQL高阶/9.服务器优化/1.硬件配置/config.json

-{
-  "node_id": "mysql-f2a76883814745b9979541ed4117754f",
-  "keywords": [],
-  "children": [],
-  "export": [],
-  "keywords_must": [],
-  "keywords_forbid": [],
-  "group": 0
-}
\ No newline at end of file

data/3.MySQL高阶/9.服务器优化/3.配置项优化/config.json → data/3.MySQL高阶/9.服务器优化/1.配置项优化/config.json

@@ -2,7 +2,9 @@
   "node_id": "mysql-6d4f4d7aecfb4546a8163256859562e1",
   "keywords": [],
   "children": [],
-  "export": [],
+  "export": [
+    "configuration.json"
+  ],
   "keywords_must": [],
   "keywords_forbid": [],
   "group": 0

data/3.MySQL高阶/9.服务器优化/1.配置项优化/configuration.json

+{
+  "type": "code_options",
+  "author": null,
+  "source": "configuration.md",
+  "notebook_enable": false,
+  "exercise_id": "b90270843de54822a1556cb47ca49394"
+}
\ No newline at end of file

data/3.MySQL高阶/9.服务器优化/1.配置项优化/configuration.md

+# 配置项优化
+
+Joe 要帮助开发部优化交易数据库的性能，下面哪些优化是可能有帮助的？
+
+1. 适当增大MySQL的最大连接数 max_connections， 提高并发响应能力。
+2. 适当增大 table_cache，提高同时打开表的个数。此参数需根据业务需要有节制的上调
+3. 适当增大 table_open_cache，提高数据表的缓存数量。
+4. 适当调整 innodb_buffer_pool_size：此配置项决定着InnoDB存储引擎的数据表的数据和索引数据的最大缓冲区大小。一般可以分配80%的物理内存。
+5. 适当增加 innodb_log_buffer_size，减少频繁的日志写操作。
+6. 如果存在较多的排序操作，调整 sort_buffer_size：排序缓冲区的大小。
+7. read_buffer_size：数据表的读缓冲区。适当增加此配置项的值，能够提高MySQL的并发读能力。
+8. back_log：如果MySQL服务器需要在短时间内处理大量的连接请求，则可以适当增大此配置项的值。
+9. thread_cache_size：MySQL缓存的数据库服务线程的最大线程数。当有大量客户端连接MySQL时，可以适当增大此配置项的值。
+10. innodb_lock_wait_timeout：InnoDB存储引擎等待行锁的时间，默认值为50ms。对于实时要求高的应用，可以将此配置项的值适当调小。
+
+## 答案
+
+全部都是
+
+## 选项
+
+### A
+
+```
+1, 2, 3, 4, 5
+```
+
+### B
+
+```
+1, 2, 3, 4, 5, 6, 7, 8
+```
+
+### C
+
+```
+1, 2, 3, 4, 5, 6, 7, 8
+```
+
+### D
+
+```
+4, 5, 6, 7, 8
+```
+
+
+

data/3.MySQL高阶/9.服务器优化/4.performance_schema/config.json → data/3.MySQL高阶/9.服务器优化/2.performance_schema/config.json

 {
   "node_id": "mysql-36d638345c1949f7bb032baf8d9f996e",
-  "keywords": [],
+  "keywords": [
+    "performance",
+    "performance schema",
+    "优化"
+  ],
   "children": [],
-  "export": [],
+  "export": [
+    "performance_schema.json"
+  ],
   "keywords_must": [],
   "keywords_forbid": [],
   "group": 0

data/3.MySQL高阶/9.服务器优化/2.performance_schema/performance_schema.json

+{
+  "type": "code_options",
+  "author": null,
+  "source": "performance_delete.md",
+  "notebook_enable": false,
+  "exercise_id": "cea8e3db523b4f1fb9a502e1d9c27d7b"
+}
\ No newline at end of file

data/3.MySQL高阶/9.服务器优化/2.performance_schema/performance_schema.md

+# # Performance Schema
+
+Joe 为交易库开启了 Performance Schema 配置。那么对于交易数据库的优化，哪些是他应该关注的？
+
+1. 从 `performance_schema.events_waits_current` 活跃线程的执行操作
+2. 从 `performance_schema.file_summary_by_event_name` 获取被频繁使用的文件，特别是经常需要等待的文件
+3. 从 `performance.events_statements_summary_by_diges` 获取 MySQL 的统计信息
+
+## 答案
+
+所有都是。
+
+## 选项
+
+### A
+
+所有都不是，performance_schema 中不包含这些信息，它们来自 Sys 数据库。
+
+### B
+
+```
+1, 2
+```
+
+### C
+
+```
+2, 3
+```
\ No newline at end of file

data/3.MySQL高阶/9.服务器优化/2.系统内核/config.json

-{
-  "node_id": "mysql-4a1bb52626b04dabac78af8eafea868e",
-  "keywords": [],
-  "children": [],
-  "export": [],
-  "keywords_must": [],
-  "keywords_forbid": [],
-  "group": 0
-}
\ No newline at end of file

data/3.MySQL高阶/9.服务器优化/5.sys数据库/config.json → data/3.MySQL高阶/9.服务器优化/3.sys数据库/config.json

@@ -2,7 +2,9 @@
   "node_id": "mysql-3d5c8647b1674de18c8348454d16fee5",
   "keywords": [],
   "children": [],
-  "export": [],
+  "export": [
+    "sys.json"
+  ],
   "keywords_must": [],
   "keywords_forbid": [],
   "group": 0

data/3.MySQL高阶/9.服务器优化/3.sys数据库/sys.json

+{
+  "type": "code_options",
+  "author": null,
+  "source": "sys.md",
+  "notebook_enable": false,
+  "exercise_id": "ed53fabf084c4ceb99952f5196412b49"
+}
\ No newline at end of file

data/3.MySQL高阶/9.服务器优化/3.sys数据库/sys.md

+# Sys 数据库
+
+Joe 计划从交易数据库服务器的 sys 系统库获取一些优化线索，下列哪些操作是他需要关注的？
+
+1. 通过 `SELECT * FROM sys.schema_unused_indexes` 找到未使用的索引
+2. 通过 `SELECT * FROM sys.schema_redundant_indexes` 找到冗余索引
+3. 通过 `SELECT * FROM sys.user_summary` 观察每用户资源消耗
+4. 通过 `SELECT * FROM sys.host_summary` 观察每连接消耗
+
+提示：交易数据库仅由DBA和应用程序连接，应用程序使用大量相同配置和登录信息的连接访
+问数据库，交易系统访问数据库时，希望尽可能的快速、高并发、每个查询的时间尽可能短。
+
+## 答案
+
+```
+1, 2, 4
+```
+
+## 选项
+
+### A
+
+所有都是
+
+### B
+
+```
+3
+```
+
+### C
+
+```
+1, 3, 4
+```
+
+### C
+
+```
+2, 3, 4
+```
\ No newline at end of file

data/3.MySQL高阶/9.服务器优化/6.资源组/config.json

-{
-  "node_id": "mysql-715cc1f656df4b099d952145a53dd006",
-  "keywords": [],
-  "children": [],
-  "export": [],
-  "keywords_must": [],
-  "keywords_forbid": [],
-  "group": 0
-}
\ No newline at end of file