Updated on 2022-08-16 GMT+08:00

B-tree Indexes

GaussDB(DWS) supports B-tree indexes, but the position of the USING BTREE keyword in a statement is different from that in MySQL. DSC will perform adaptation based on GaussDB features during migration.

  1. Inline B-tree index

    Input

    CREATE TABLE `public`.`test_create_table03` (
    	`DEMAND_ID` INT(11) NOT NULL AUTO_INCREMENT,
    	`DEMAND_NAME` CHAR(100) NOT NULL,
    	`THEME` VARCHAR(200) NULL DEFAULT NULL,
    	`SEND_ID` INT(11) NULL DEFAULT NULL,
    	`SEND_NAME` CHAR(20) NULL DEFAULT NULL,
    	`SEND_TIME` DATETIME NULL DEFAULT NULL,
    	`DEMAND_CONTENT` TEXT NOT NULL,
    	PRIMARY KEY(`DEMAND_ID`),
    	INDEX THEME_INDEX(THEME) USING BTREE,
        INDEX NAME_INDEX USING BTREE (SEND_NAME(10))
    );

    Output

    CREATE TABLE "public"."test_create_table03"
    (
      "demand_id" SERIAL NOT NULL,
      "demand_name" CHAR(100) NOT NULL,
      "theme" VARCHAR(200) DEFAULT NULL,
      "send_id" INTEGER(11) DEFAULT NULL,
      "send_name" CHAR(20) DEFAULT NULL,
      "send_time" TIMESTAMP WITHOUT TIME ZONE DEFAULT NULL,
      "demand_content" TEXT NOT NULL,
      PRIMARY KEY ("demand_id")
    )
      WITH ( ORIENTATION = ROW, COMPRESSION = NO )
      NOCOMPRESS
      DISTRIBUTE BY HASH ("demand_id");
    CREATE INDEX "theme_index" ON "public"."test_create_table03" USING BTREE ("theme");
    CREATE INDEX "name_index" ON "public"."test_create_table03" USING BTREE ("send_name");
  2. B-tree index created by ALTER TABLE

    Input

    CREATE TABLE IF NOT EXISTS `public`.`runoob_alter_test`(
        `dataType1` int NOT NULL AUTO_INCREMENT,
        `dataType2` FLOAT(10,2),
        PRIMARY KEY(`dataType1`)
    );
    
    ALTER TABLE runoob_alter_test ADD KEY alterTable_addKey_indexType (dataType1) USING BTREE;

    Output

    CREATE TABLE "public"."runoob_alter_test"
    (
      "datatype1" SERIAL NOT NULL,
      "datatype2" FLOAT(10),
      PRIMARY KEY ("datatype1")
    )
      WITH ( ORIENTATION = ROW, COMPRESSION = NO )
      NOCOMPRESS
      DISTRIBUTE BY HASH ("datatype1");
    
    CREATE INDEX "altertable_addkey_indextype" ON "public"."runoob_alter_test" ("datatype1");
  3. B-tree index created by CREATE INDEX

    Input

    CREATE TABLE `public`.`test_create_table03` (
    	`DEMAND_ID` INT(11) NOT NULL AUTO_INCREMENT,
    	`DEMAND_NAME` CHAR(100) NOT NULL,
    	`THEME` VARCHAR(200) NULL DEFAULT NULL,
    	`SEND_ID` INT(11) NULL DEFAULT NULL,
    	`SEND_NAME` CHAR(20) NULL DEFAULT NULL,
    	`SEND_TIME` DATETIME NULL DEFAULT NULL,
    	`DEMAND_CONTENT` TEXT NOT NULL,
    	PRIMARY KEY(`DEMAND_ID`),
        INDEX CON_INDEX(DEMAND_CONTENT(100)) USING HASH ,
        INDEX SEND_INFO_INDEX USING HASH (SEND_ID,SEND_NAME(10),SEND_TIME)
    );
    
    
    CREATE TABLE `public`.`test_index_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`)
    );
    CREATE UNIQUE INDEX USER_ID_INDEX USING BTREE ON TEST_INDEX_TABLE05(USER_ID);
    CREATE INDEX USER_NAME_INDEX USING BTREE ON TEST_INDEX_TABLE05(USER_NAME(10));
    CREATE INDEX DETAIL_INDEX ON TEST_INDEX_TABLE05(DETAIL(50)) USING BTREE;
    CREATE INDEX USER_INFO_INDEX USING BTREE ON TEST_INDEX_TABLE05(USER_ID,USER_NAME(10));

    Output

    CREATE TABLE "public"."test_index_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_id_index" ON "public"."test_index_table05" ("user_id");
    CREATE INDEX "user_name_index" ON "public"."test_index_table05" USING BTREE ("user_name");
    CREATE INDEX "detail_index" ON "public"."test_index_table05" USING BTREE ("detail");
    CREATE INDEX "user_info_index" ON "public"."test_index_table05" USING BTREE ("user_id","user_name");