更新时间:2022-06-13 GMT+08:00

普通索引和前缀索引

GaussDB(DWS) 不支持前缀索引,也不支持内联普通索引。DSC工具迁移时会根据GaussDB的特性将其迁移为普通索引。

  1. 内联普通(前缀)索引

    输入示例

    CREATE TABLE IF NOT EXISTS `public`.`runoob_dataType_test`
    (
      `id` INT PRIMARY KEY AUTO_INCREMENT,
      `name` VARCHAR(128) NOT NULL,
      INDEX index_single(name(10))
    );

    输出示例

    CREATE TABLE "public"."runoob_datatype_test"
    (
      "id" SERIAL PRIMARY KEY,
      "name" VARCHAR(128) NOT NULL
    )
      WITH ( ORIENTATION = ROW, COMPRESSION = NO )
      NOCOMPRESS
      DISTRIBUTE BY HASH ("id");
    CREATE INDEX "index_single" ON "public"."runoob_datatype_test" USING BTREE ("name");
  2. ALTER TABLE创建普通(前缀)索引

    输入示例

    CREATE TABLE `public`.`test_create_table05` (
     `ID` INT(11) NOT NULL AUTO_INCREMENT,
     `USER_ID` INT(20) NOT NULL,
     `USER_NAME` CHAR(20) NULL DEFAULT NULL,
     `DETAIL` VARCHAR(100) NULL DEFAULT NULL,
     PRIMARY KEY (`ID`)
    );
    
    ALTER TABLE TEST_CREATE_TABLE05 ADD INDEX USER_NAME_INDEX_02(USER_NAME(10));

    输出示例

    CREATE TABLE "public"."test_create_table05"
    (
      "id" SERIAL NOT NULL,
      "user_id" INTEGER(20) NOT NULL,
      "user_name" CHAR(20) DEFAULT NULL,
      "detail" VARCHAR(100) DEFAULT NULL,
      PRIMARY KEY ("id")
    )
      WITH ( ORIENTATION = ROW, COMPRESSION = NO )
      NOCOMPRESS
      DISTRIBUTE BY HASH ("id");
    
    CREATE INDEX "user_name_index_02" ON "public"."test_create_table05" ("user_name");
  3. CREATE INDEX创建普通(前缀)索引

    输入示例

    CREATE TABLE IF NOT EXISTS `public`.`customer`(
        `name` varchar(64) primary key,
    	id integer,
    	id2 integer
    );
    
    CREATE INDEX part_of_name ON customer (name(10));

    输出示例

    CREATE TABLE "public"."customer"
    (
      "name" VARCHAR(64) PRIMARY KEY,
      "id" INTEGER,
      "id2" INTEGER
    )
      WITH ( ORIENTATION = ROW, COMPRESSION = NO )
      NOCOMPRESS
      DISTRIBUTE BY HASH ("name");
    
    CREATE INDEX "part_of_name" ON "public"."customer" USING BTREE ("name");