基于Calcite的分布式多数据源查询

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发布于 2022-02-25 09:33:55

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发布于 2022-02-25 09:33:55

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在本文中，我们将实践 GBase8s 和 MySQL 的跨数据源联合查询，案例中 MySQL 数据源中存放商品信息，GBase8s 数据源中存放订单信息。整体架构如下

好了，我们开始吧。

环境准备

GBase8s

安装镜像 docker pull liaosnet/gbase8s启动容器 docker run -itd -p 19088:9088 liaosnet/gbase8s容器基本信息：

JDBC JAR：/home/gbase/gbasedbtjdbc_3.3.0_2.jar
类名：com.gbasedbt.jdbc.Driver
URL：jdbc:gbasedbt-sqli://IPADDR:19088/testdb:GBASEDBTSERVER=gbase01;DB_LOCALE=zh_CN.utf8;CLIENT_LOCALE=zh_CN.utf8;IFX_LOCK_MODE_WAIT=30;
用户：gbasedbt
密码：GBase123
其中：IPADDR为docker所在机器的IP地址，同时需要放通19088端口。

MySQL

安装镜像 docker pull liaosnet/gbase8s启动容器 docker run -p 3306:3306 --name mysql -e MYSQL_ROOT_PASSWORD=dafei1288 -d mysql

数据准备

GBase8s

CREATE TABLE order_table (
 oid INTEGER NOT NULL,
 iid INTEGER,
 icount INTEGER,
 PRIMARY KEY (oid) CONSTRAINT order_table_pk
);

INSERT INTO order_table (oid, iid, icount) VALUES(1, 1, 10);
INSERT INTO order_table (oid, iid, icount) VALUES(2, 3, 30);

MySQL

create table item
(
    i_id    int auto_increment
        primary key,
    catalog varchar(20) null,
    pname   varchar(20) null,
    price   float       null,
    constraint item_i_id_uindex
        unique (i_id)
);

INSERT INTO test.item (i_id, catalog, pname, price) VALUES (1, '游戏', '大航海时代IV', 300);
INSERT INTO test.item (i_id, catalog, pname, price) VALUES (2, '游戏', '马车8', 300);
INSERT INTO test.item (i_id, catalog, pname, price) VALUES (3, '食品', '青椒豆腐乳西瓜', 20);

工程准备

创建 maven 工程，目录如下图所示:

添加依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>calcite_multi_database</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.apache.calcite</groupId>
            <artifactId>calcite-core</artifactId>
            <version>1.29.0</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.28</version>
        </dependency>
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.8.9</version>
        </dependency>
        <dependency>
            <groupId>gbase</groupId>
            <artifactId>gbasedbt</artifactId>
            <version>330</version>
            <scope>system</scope>
            <systemPath>${project.basedir}/libs/gbasedbtjdbc_3.3.0_2_36477d.jar</systemPath>
        </dependency>
    </dependencies>
</project>

添加数据源配置文件 `multiSource.json`

{
  "defaultSchema": "gbasedbt",
  "schemas": [
    {
      "factory": "org.apache.calcite.adapter.jdbc.JdbcSchema$Factory",
      "name": "mysql",
      "operand": {
        "jdbcDriver": "com.mysql.cj.jdbc.Driver",
        "jdbcUrl": "jdbc:mysql://localhost:3306/test",
        "jdbcUser": "root",
        "jdbcPassword": "dafei1288"
      },
      "type": "custom"
    },
    {
      "factory": "org.apache.calcite.adapter.jdbc.JdbcSchema$Factory",
      "name": "gbasedbt",
      "operand": {
        "jdbcDriver": "com.gbasedbt.jdbc.Driver",
        "jdbcUrl": "jdbc:gbasedbt-sqli://localhost:19088/testdb:GBASEDBTSERVER=gbase01;DB_LOCALE=zh_CN.utf8;CLIENT_LOCALE=zh_CN.utf8;IFX_LOCK_MODE_WAIT=30;",
        "jdbcUser": "gbasedbt",
        "jdbcPassword": "GBase123"
      },
      "type": "custom"
    }
  ],
  "version": "1.0"
}

创建执行程序 `MultiSource`

使用上面的配置文件，创建 Calcite Jdbc 链接

String filepath = "E:\\working\\GBase\\writting\\calcite_multi_database_select\\calcite_multi_database\\src\\main\\resources\\multiSource.json";
Properties config = new Properties();
config.put("model",filepath);
config.put("lex", "MYSQL");

这里 config.put("lex", "MYSQL"); 用于解析外层 SQL ，所以必须保留。使用查询语句 SELECT o.oid,o.iid,o.icount,i.catalog,i.pname,i.price FROM gbasedbt.order_table AS o join mysql.item AS i on o.iid = i.i_id 进行数据查询。

除了执行结果，其实我们也会对执行的逻辑计划感兴趣，那么我们来看看如何将该 SQL 的逻辑计划打印出来

public static void printLogicPlan(String modelPath , String sql) throws Exception{

        String modelJsonStr = Files.readAllLines(Paths.get(modelPath)).stream().collect(Collectors.joining("\n"));
        HashMap map = new Gson().fromJson(modelJsonStr, HashMap.class);
        List<Map> schemas = (List<Map>) map.get("schemas");

        SchemaPlus rootSchema = Frameworks.createRootSchema(true);
        Schema gbasedbt = JdbcSchema.create(rootSchema, "gbasedbt" , (Map<String,Object>)schemas.get(1).get("operand"));
        Schema mysql = JdbcSchema.create(rootSchema, "mysql" , (Map<String,Object>)schemas.get(0).get("operand"));
        rootSchema.add("gbasedbt",gbasedbt);
        rootSchema.add("mysql",mysql);

        SqlParser.Config insensitiveParser = SqlParser.configBuilder()
                .setCaseSensitive(false)
                .build();

        FrameworkConfig config = Frameworks.newConfigBuilder()
                .parserConfig(insensitiveParser)
                .defaultSchema(rootSchema)
                .build();

        Planner planner = Frameworks.getPlanner(config);
        SqlNode sqlNode = planner.parse(sql);
        SqlNode sqlNodeValidated = planner.validate(sqlNode);
        RelRoot relRoot = planner.rel(sqlNodeValidated);
        RelNode relNode = relRoot.project();

        System.out.println(sqlNode.toSqlString(MysqlSqlDialect.DEFAULT));
        System.out.println();
        System.out.println(relNode.explain());
}

下面是逻辑计划打印的结果，我们不难看出，这里是使用了2个全表扫描，然后再通过 Join 算子，然后进行 project算子的。其实这个执行不能说效率很高吧，只能说非常慢，如果想做优化，我们以后再开一篇文章。

LogicalProject(OID=[$0], IID=[$1], ICOUNT=[$2], CATALOG=[$4], PNAME=[$5], PRICE=[$6])
  LogicalJoin(condition=[=($1, $3)], joinType=[inner])
    JdbcTableScan(table=[[gbasedbt, order_table]])
    JdbcTableScan(table=[[mysql, item]])

SQL 查询结果如下

oid iid icount catalog pname price 
1 1 10 游戏 大航海时代IV 300.0 
2 3 30 食品 青椒豆腐乳西瓜 20.0

执行截图

完整代码清单：

package wang.datahub;

import com.google.gson.Gson;
import org.apache.calcite.adapter.jdbc.JdbcSchema;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.RelRoot;
import org.apache.calcite.rel.RelWriter;
import org.apache.calcite.rel.externalize.RelWriterImpl;
import org.apache.calcite.schema.Schema;
import org.apache.calcite.schema.SchemaPlus;
import org.apache.calcite.sql.SqlExplainLevel;
import org.apache.calcite.sql.SqlNode;
import org.apache.calcite.sql.dialect.MysqlSqlDialect;
import org.apache.calcite.sql.parser.SqlParser;
import org.apache.calcite.tools.FrameworkConfig;
import org.apache.calcite.tools.Frameworks;
import org.apache.calcite.tools.Planner;


import java.io.PrintWriter;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.sql.*;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.stream.Collectors;

public class MultiSource {
    public static void main(String[] args)  throws Exception{
        String filepath = "E:\\working\\GBase\\writting\\calcite_multi_database_select\\calcite_multi_database\\src\\main\\resources\\multiSource.json";
        Properties config = new Properties();
        config.put("model",filepath);
        config.put("lex", "MYSQL");
        String sql =
                "SELECT o.oid,o.iid,o.icount,i.catalog,i.pname,i.price FROM gbasedbt.order_table AS o join mysql.item AS i on o.iid = i.i_id";

        try (Connection con = DriverManager.getConnection("jdbc:calcite:", config)) {
            try (Statement stmt = con.createStatement()) {
                try (ResultSet rs = stmt.executeQuery(sql)) {
                    //打印逻辑计划
                    printLogicPlan(filepath,sql);
                    //打印查询结果
                    printRs(rs);
                }
            }
        }

    }

    public static void printRs(ResultSet rs) throws Exception {
        ResultSetMetaData rsmd = rs.getMetaData();
        int count = rsmd.getColumnCount();

        for(int i = 1; i <= count; i++){
            System.out.print(rsmd.getColumnName(i)+"\t");
        }
        System.out.println();

        while(rs.next()){
            for(int i = 1; i <= count; i++){
                System.out.print(rs.getString(i)+"\t");
            }
            System.out.println();
        }
    }

    public static void printLogicPlan(String modelPath , String sql) throws Exception{

        String modelJsonStr = Files.readAllLines(Paths.get(modelPath)).stream().collect(Collectors.joining("\n"));
        HashMap map = new Gson().fromJson(modelJsonStr, HashMap.class);
        List<Map> schemas = (List<Map>) map.get("schemas");

        SchemaPlus rootSchema = Frameworks.createRootSchema(true);
        Schema gbasedbt = JdbcSchema.create(rootSchema, "gbasedbt" , (Map<String,Object>)schemas.get(1).get("operand"));
        Schema mysql = JdbcSchema.create(rootSchema, "mysql" , (Map<String,Object>)schemas.get(0).get("operand"));
        rootSchema.add("gbasedbt",gbasedbt);
        rootSchema.add("mysql",mysql);

        SqlParser.Config insensitiveParser = SqlParser.configBuilder()
                .setCaseSensitive(false)
                .build();

        FrameworkConfig config = Frameworks.newConfigBuilder()
                .parserConfig(insensitiveParser)
                .defaultSchema(rootSchema)
                .build();

        Planner planner = Frameworks.getPlanner(config);
        SqlNode sqlNode = planner.parse(sql);
        SqlNode sqlNodeValidated = planner.validate(sqlNode);
        RelRoot relRoot = planner.rel(sqlNodeValidated);
        RelNode relNode = relRoot.project();

        System.out.println(sqlNode.toSqlString(MysqlSqlDialect.DEFAULT));
        System.out.println();
        System.out.println(relNode.explain());
    }
}

好了，现在我们初步完成了基于 GBase8s 的跨数据源查询工作，下一篇文章我们来说说查询优化。提前祝广大读者朋友，新春快乐，虎虎生威 ...

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