Mysql学习

一、java api 实现索引管理

1.1 创建索引

1.1.1 获取客户端

RestClientBuilder restClientBuilder = RestClient.builder(new HttpHost("113.31.112.15", 9200, "http")).setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
    @Override
    public HttpAsyncClientBuilder customizeHttpClient(HttpAsyncClientBuilder httpAsyncClientBuilder) {
        CredentialsProvider basicCredentialsProvider = new BasicCredentialsProvider();
        basicCredentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials("elastic", "zCAgwD2wXL7uDMFnVsNQ"));
        return httpAsyncClientBuilder.setDefaultCredentialsProvider(basicCredentialsProvider);
    }
});
RestHighLevelClient client = new RestHighLevelClient(restClientBuilder);

1.1.2 setting

final CreateIndexRequest my_index = new CreateIndexRequest("my_index");
my_index.settings(Settings.builder()
                .put("number_of_shards", "1")
                .put("number_of_replicas", "1")
        .build());

1.1.3 mapping

// 1.
my_index.mapping("json", XContentType.JSON);

// 2
Map<String, Object> f1 = new HashMap<>();
Map<String, Object> f2 = new HashMap<>();
f1.put("type", "text");
f2.put("type", "text");

Map<String, Object> properties = new HashMap<>();
properties.put("field1", f1);
properties.put("field2", f2);

Map<String, Object> mapping = new HashMap<>();
mapping.put("properites", properties);
my_index.mapping(mapping);

// 3
XContentBuilder builder = XContentFactory.jsonBuilder();
builder.startObject();
{
    builder.startObject("properties");
    {
        builder.startObject("field1");
        {
            builder.field("type", "text");
        }
        builder.endObject();
        builder.startObject("field2");
        {
            builder.field("type", "text");
        }
        builder.endObject();
    }
    builder.endObject();
}
builder.endObject();
my_index.mapping(builder);

1.1.4 别名

my_index.alias(new Alias("hello"));

1.1.5 其他配置

// 设置超时时间
my_index.setTimeout(TimeValue.timeValueSeconds(10));
// 主节点超时时间
my_index.setMasterTimeout(TimeValue.timeValueSeconds(5));
// 创建索引api返回相应之前等待活动分片的数量
my_index.waitForActiveShards(ActiveShardCount.from(1));

1.1.6 结果

CreateIndexResponse createIndexResponse = client.indices().create(my_index, RequestOptions.DEFAULT);

final boolean acknowledged = createIndexResponse.isAcknowledged();
final boolean shardsAcknowledged = createIndexResponse.isShardsAcknowledged();

1.1.7 异步执行

ActionListener<CreateIndexResponse> actionListener = new ActionListener<CreateIndexResponse>() {

    @Override
    public void onResponse(CreateIndexResponse createIndexResponse) {

    }

    @Override
    public void onFailure(Exception e) {

    }
};
client.indices().createAsync(my_index, RequestOptions.DEFAULT, actionListener);

1.2 删除索引

final DeleteIndexRequest my_index1 = new DeleteIndexRequest("my_index");
final AcknowledgedResponse delete = client.indices().delete(my_index1, RequestOptions.DEFAULT);
final boolean acknowledged1 = delete.isAcknowledged();

1.3 查看索引

final GetIndexRequest my_index2 = new GetIndexRequest("my_index");
// 从主节点返回本地索引信息状态
my_index2.local(true);
// 以适合人类的格式返回
my_index2.humanReadable(true);
// 是否返回每个索引的所有默认配置
my_index2.includeDefaults(false);

final boolean exists = client.indices().exists(my_index2, RequestOptions.DEFAULT);

1.4 关闭索引

final CloseIndexRequest my_index3 = new CloseIndexRequest("my_index");
final CloseIndexResponse close = client.indices().close(my_index3, RequestOptions.DEFAULT);
final boolean acknowledged2 = close.isAcknowledged();

1.5 开启索引

final OpenIndexRequest my_index4 = new OpenIndexRequest("my_index");
final OpenIndexResponse open = client.indices().open(my_index4, RequestOptions.DEFAULT);
final boolean acknowledged3 = open.isAcknowledged();

二、搜索语法入门

2.1 query string searc

无条件搜索

GET /book/_search

• took: 花费多长时间
• time_out：是否超时
• _shards：
  • total：总共分片数
  • successful：成功分片数
  • skipped：跳过分片数
  • failed：失败分片数
• total：查询总数
• max_score：就是docuemnt对于一个search的相关度的匹配分数，越相关，就越匹配，分数就越高。

2.2 传参

与http请求传参类似

GET book/_search?q=name:java&sort=price:desc

类比

select * from book where name like '%java%' order by price desc

2.3 图解timeout机制

指定每个shard只能在给定的时间内查询数据，能有几条就返回几条，返回给客户端，保住了业务。

• 请求设置

  GET book/_search?timeout=10ms

• 全局设置
  配置文件中设置search.default_search_timeout: 100ms，默认不超时。

三、multi-index多索引搜索

3.1 搜索模式

/_search                查询索引下所有数据
/index1/_search         查询指定索引下所有数据
/index1,index2/_search  查询两个索引下的数据
/index*/_search         匹配规则下的所有索引

应用场景：生产环境log可以按照日志分开。

3.2 图解简单的搜索原理

四、分页搜索

4.1 分页搜索的语法

sql: select * from book limit 1,5
size, from

例子

GET /book/_search?size=10

五、query string基础语法

六、query DSL入门

七、Fiter

八、定位错误语法和定制排序规则

九、Text字段排序问题

十、Scroll分批查询

十一、java api实现搜索

十二、tfidf算法

十三、Doc value

十四、搜索参数小结

十五、聚合查询

十六、es7 sql新特性