forked from docs/doc-exports
Lu, Huayi
346ac31da9
Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com> Reviewed-by: Jiang, Beibei <beibei.jiang@t-systems.com> Co-authored-by: Lu, Huayi <luhuayi@huawei.com> Co-committed-by: Lu, Huayi <luhuayi@huawei.com>
114 lines
8.2 KiB
HTML
114 lines
8.2 KiB
HTML
<a name="EN-US_TOPIC_0000001188202552"></a><a name="EN-US_TOPIC_0000001188202552"></a>
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<h1 class="topictitle1">Unique Indexes</h1>
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<div id="body8662426"><div class="caution" id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_note49007161318"><span class="cautiontitle"><img src="public_sys-resources/caution_3.0-en-us.png"> </span><div class="cautionbody"><p id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_p790207191318">If MySQL unique indexes (constraints) and primary key constraints are used together during migration, OLAP distribution keys may become unavailable. Therefore, this scenario is not supported by DSC.</p>
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</div></div>
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<ol id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_ol12553123692615"><li id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_li15553183615265">If there is an inline unique index, DSC will delete it directly.<p id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_p135691921172717"><a name="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_li15553183615265"></a><a name="en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_li15553183615265"></a><strong id="EN-US_TOPIC_0000001188202552__en-us_topic_0237712486_b414614420426">Input</strong></p>
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<pre class="screen" id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_screen182799185276">CREATE TABLE IF NOT EXISTS `public`.`runoob_dataType_test`
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(
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`id` INT PRIMARY KEY AUTO_INCREMENT,
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`name` VARCHAR(128) NOT NULL,
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UNIQUE (id ASC)
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);</pre>
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<p id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_p77858251279"><strong id="EN-US_TOPIC_0000001188202552__en-us_topic_0237712486_b12146154215426">Output</strong></p>
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<pre class="screen" id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_screen71919285272">CREATE TABLE "public"."runoob_datatype_test"
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(
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"id" SERIAL PRIMARY KEY,
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"name" VARCHAR(128) NOT NULL
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)
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WITH ( ORIENTATION = ROW, COMPRESSION = NO )
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NOCOMPRESS
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DISTRIBUTE BY HASH ("id");</pre>
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</li><li id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_li19672194516269">If there is a unique index created by <strong id="EN-US_TOPIC_0000001188202552__en-us_topic_0237712486_b814634214426">ALTER TABLE</strong>, DSC will create a normal index based on GaussDB features.<p id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_p1287443289"><strong id="EN-US_TOPIC_0000001188202552__en-us_topic_0237712486_b7146124216427">Input</strong></p>
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<pre class="screen" id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_screen9287164132817">CREATE TABLE IF NOT EXISTS `public`.`runoob_alter_test`(
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`dataType1` int,
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`dataType2` FLOAT(10,2),
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`dataType3` DOUBLE(20,8)
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)ENGINE=InnoDB DEFAULT CHARSET=utf8;
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ALTER TABLE runoob_alter_test ADD UNIQUE idx_runoob_alter_test_datatype1(dataType1);
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ALTER TABLE runoob_alter_test ADD UNIQUE INDEX idx_runoob_alter_test_datatype1(dataType2);
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ALTER TABLE runoob_alter_test ADD UNIQUE KEY idx_runoob_alter_test_datatype1(dataType3);
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CREATE TABLE IF NOT EXISTS `public`.`runoob_alter_test`(
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`dataType1` int,
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`dataType2` FLOAT(10,2),
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`dataType3` DOUBLE(20,8),
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`dataType4` TEXT NOT NULL,
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`dataType5` YEAR NOT NULL DEFAULT '2018',
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`dataType6` DATETIME NOT NULL DEFAULT '2018-10-12 15:27:33.999999'
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)ENGINE=InnoDB DEFAULT CHARSET=utf8;
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ALTER TABLE runoob_alter_test ADD CONSTRAINT UNIQUE idx_runoob_alter_test_datatype1(dataType1);
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ALTER TABLE runoob_alter_test ADD CONSTRAINT UNIQUE INDEX idx_runoob_alter_test_datatype2(dataType2);
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ALTER TABLE runoob_alter_test ADD CONSTRAINT UNIQUE KEY idx_runoob_alter_test_datatype3(dataType3);
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ALTER TABLE runoob_alter_test ADD CONSTRAINT constraint_dataType UNIQUE idx_runoob_alter_test_datatype4(dataType4);
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ALTER TABLE runoob_alter_test ADD CONSTRAINT constraint_dataType UNIQUE INDEX idx_runoob_alter_test_datatype5(dataType5);
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ALTER TABLE runoob_alter_test ADD CONSTRAINT constraint_dataType UNIQUE KEY idx_runoob_alter_test_datatype6(dataType6);</pre>
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<p id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_p142870442811"><strong id="EN-US_TOPIC_0000001188202552__en-us_topic_0237712486_b0146114217424">Output</strong></p>
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<pre class="screen" id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_screen19288648288">CREATE TABLE "public"."runoob_alter_test"
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(
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"datatype1" INTEGER,
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"datatype2" FLOAT(10),
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"datatype3" FLOAT(20)
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)
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WITH ( ORIENTATION = ROW, COMPRESSION = NO )
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NOCOMPRESS
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DISTRIBUTE BY HASH ("datatype1");
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CREATE INDEX "idx_runoob_alter_test_datatype1" ON "public"."runoob_alter_test" ("datatype1");
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CREATE INDEX "idx_runoob_alter_test_datatype1" ON "public"."runoob_alter_test" ("datatype2");
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CREATE INDEX "idx_runoob_alter_test_datatype1" ON "public"."runoob_alter_test" ("datatype3");
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CREATE TABLE "public"."runoob_alter_test"
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(
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"datatype1" INTEGER,
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"datatype2" FLOAT(10),
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"datatype3" FLOAT(20),
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"datatype4" TEXT NOT NULL,
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"datatype5" VARCHAR(4) NOT NULL DEFAULT '2018',
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"datatype6" TIMESTAMP WITHOUT TIME ZONE NOT NULL DEFAULT '2018-10-12 15:27:33.999999'
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)
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WITH ( ORIENTATION = ROW, COMPRESSION = NO )
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NOCOMPRESS
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DISTRIBUTE BY HASH ("datatype1");
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CREATE INDEX "idx_runoob_alter_test_datatype1" ON "public"."runoob_alter_test" ("datatype1");
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CREATE INDEX "idx_runoob_alter_test_datatype2" ON "public"."runoob_alter_test" ("datatype2");
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CREATE INDEX "idx_runoob_alter_test_datatype3" ON "public"."runoob_alter_test" ("datatype3");
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CREATE INDEX "idx_runoob_alter_test_datatype4" ON "public"."runoob_alter_test" ("datatype4");
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CREATE INDEX "idx_runoob_alter_test_datatype5" ON "public"."runoob_alter_test" ("datatype5");
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CREATE INDEX "idx_runoob_alter_test_datatype6" ON "public"."runoob_alter_test" ("datatype6");</pre>
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</li><li id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_li1937655815268">If there is a unique index created by <strong id="EN-US_TOPIC_0000001188202552__en-us_topic_0237712486_b5147842204215">CREATE INDEX</strong>, DSC will create a normal index based on GaussDB features.<p id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_p15863552819"><strong id="EN-US_TOPIC_0000001188202552__en-us_topic_0237712486_b514714218424">Input</strong></p>
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<pre class="screen" id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_screen758620572815">CREATE TABLE `public`.`test_index_table01` (
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`TABLE01_ID` INT(11) NOT NULL,
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`TABLE01_THEME` VARCHAR(100) NULL DEFAULT NULL,
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`AUTHOR_NAME` CHAR(10) NULL DEFAULT NULL,
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`AUTHOR_ID` INT(11) NULL DEFAULT NULL,
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`CREATE_TIME` INT NULL DEFAULT NULL,
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PRIMARY KEY(`TABLE01_ID`)
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);
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CREATE UNIQUE INDEX AUTHOR_INDEX ON `test_index_table01`(AUTHOR_ID);</pre>
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<p id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_p35869514281"><strong id="EN-US_TOPIC_0000001188202552__en-us_topic_0237712486_b61471428425">Output</strong></p>
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<pre class="screen" id="EN-US_TOPIC_0000001188202552__en-us_topic_0238518442_en-us_topic_0237362414_en-us_topic_0214164547_screen8586145162813">CREATE TABLE "public"."test_index_table01"
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(
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"table01_id" INTEGER(11) NOT NULL,
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"table01_theme" VARCHAR(100) DEFAULT NULL,
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"author_name" CHAR(10) DEFAULT NULL,
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"author_id" INTEGER(11) DEFAULT NULL,
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"create_time" INTEGER DEFAULT NULL,
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PRIMARY KEY ("table01_id")
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)
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WITH ( ORIENTATION = ROW, COMPRESSION = NO )
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NOCOMPRESS
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DISTRIBUTE BY HASH ("table01_id");
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CREATE INDEX "author_index" ON "public"."test_index_table01" ("author_id");</pre>
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</li></ol>
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</div>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="dws_sct_0013.html">MySQL Syntax Migration</a></div>
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</div>
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</div>
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