1

我有一个你可能很容易回答的问题

我在下面有一个图像表

一张图片可以有多种尺寸——三个表格是不是更好的做法

一个图像详细信息表将 image_details 连接到 image_paths 的另一个表和连接到图像路径的另一个 table-image_sizes 。

或者最好将所有图像尺寸放在图像表中。实际上，我有一张图像，但尺寸不同。寻找优化的最佳选择。所有图像都将具有每种图像尺寸，因此对于某些没有特定尺寸的图像，将来不会有冗余。我不确定是否最好使用另一张桌子，以防我们添加其他尺寸。但是我可以在图像表中添加另一列以获得新的图像大小

图像表

CREATE  TABLE IF NOT EXISTS `warrington_main`.`image` (  
  `id` MEDIUMINT(8) UNSIGNED NOT NULL AUTO_INCREMENT ,  
  `user_id` BIGINT(20) UNSIGNED NOT NULL ,  
  `alias_title` VARCHAR(255) NOT NULL ,  
  `address_id` BIGINT(20) NULL ,  
  `geolocation_id` BIGINT(20) NULL ,  
  `camera_id` MEDIUMINT(8) NULL ,  
  `title` VARCHAR(100) NOT NULL ,  
  `description` VARCHAR(2000) NOT NULL ,  
  `main_image` VARCHAR(50) NOT NULL ,  
  `thumbnail_image` VARCHAR(50) NOT NULL ,  
  `thumbnail_image_medium` VARCHAR(50) NOT NULL ,  
  `thumbnail_image_small` VARCHAR(50) NOT NULL ,  
  `thumbnail_image_gallery` VARCHAR(50) NOT NULL ,  
  `hits` BIGINT(20) UNSIGNED NOT NULL DEFAULT '0' ,  
  `show_comment` ENUM('0','1') NOT NULL ,  
  `feature_in_gallery` ENUM('0','1') NOT NULL ,  
  `created_on` DATETIME NOT NULL DEFAULT '0000-00-00 00:00:00' ,  
  `date_taken` DATETIME NOT NULL DEFAULT '0000-00-00 00:00:00' ,  
  `updated_on` DATETIME NOT NULL DEFAULT '0000-00-00 00:00:00' ,  
  `updated_by` BIGINT(20) UNSIGNED NOT NULL ,  
  `approved` ENUM('Inprocess','Yes','No') NOT NULL DEFAULT 'Inprocess' ,  
  `visible` ENUM('0','1') NOT NULL DEFAULT '0' ,  
  `account_type_created` ENUM('S','Y', 'G', 'FL', 'FB') NOT NULL ,  
  PRIMARY KEY (`id`) ,  
  UNIQUE INDEX `alias_title` (`alias_title` ASC) ,  
  INDEX `title` (`title` ASC) ,  
  INDEX `approved` (`approved` ASC) ,  
  INDEX `visible` (`visible` ASC) ,  
  INDEX `feature_in_gallery` (`feature_in_gallery` ASC) ,  
  INDEX `fk_image_image_user1_idx` (`user_id` ASC) ,  
  INDEX `fk_image_camera1_idx` (`camera_id` ASC) ,  
  INDEX `fk_image_address1_idx` (`address_id` ASC) ,  
  INDEX `fk_image_geolocation1_idx` (`geolocation_id` ASC) ,  
  INDEX `fk_image_user1_idx` (`updated_by` ASC) ,  
  CONSTRAINT `fk_image_image_user1`  
    FOREIGN KEY (`user_id` )  
    REFERENCES `warrington_main`.`user` (`id` )  
    ON DELETE NO ACTION  
    ON UPDATE NO ACTION,  
  CONSTRAINT `fk_image_camera1`  
    FOREIGN KEY (`camera_id` )    
    REFERENCES `warrington_main`.`camera` (`id` )  
    ON DELETE NO ACTION  
    ON UPDATE NO ACTION,  
  CONSTRAINT `fk_image_address1`  
    FOREIGN KEY (`address_id` )  
    REFERENCES `warrington_main`.`address` (`id` )
    ON DELETE NO ACTION  
    ON UPDATE NO ACTION,
  CONSTRAINT `fk_image_geolocation1`  
    FOREIGN KEY (`geolocation_id` )  
    REFERENCES `warrington_main`.`geolocation` (`id` )  
    ON DELETE NO ACTION  
    ON UPDATE NO ACTION,  
  CONSTRAINT `fk_image_user1`    
    FOREIGN KEY (`updated_by` )    
    REFERENCES `warrington_main`.`user` (`id` )    
    ON DELETE NO ACTION    
    ON UPDATE NO ACTION)    
ENGINE = InnoDB    
AUTO_INCREMENT = 23162    
DEFAULT CHARACTER SET = utf8
4

3 回答 3

1

一个图像详细信息表将 image_details 连接到 image_paths 的另一个表和连接到图像路径的另一个 table-image_sizes 。

This is not normalization and is referred to as Vertical Partitioning where you want the primary details of an object to be present in one table and the auxiliary details that occupy more space (in general) and are not part of general filtering criteria are moved to a different table. This is done to reduce the size of each record of the first table so that there will be more number of records in each database page and hence less number of pages to go through during filtering, less IO and faster search ability.

In your case, it seems fine to retain all attributes of an image in a single table.

于 2012-09-15T18:27:25.383 回答
0

好吧，您应该在使用多个表的情况下进行规范化，并且不要将相同的信息存储在多个地方。这种冗余避免了任何应用程序生命周期后期的数据问题。

因此，在您的情况下IMAGE_SIZE，应该是另一个IMAGE_ID定义为外键的表。

IMAGE
    ID
    IMAGE_ATTRIBUTES

IMAGE_SIZE
    ID
    IMAGE_ID
    SIZE_ATTRIBUTES 

 IMAGE_PATH
    IMAGE_ID or IMAGE_SIZE_ID (depends)
    PATH
于 2012-09-15T18:22:27.103 回答
0

在这种情况下，一张桌子可能是处理它的方法。如果所有图像 X 都有所有尺寸，并且您可能不太可能添加大量不同尺寸。

三张表也可以，但是当您并没有真正获得太多收益时，为什么还要处理联接。

Images
    ImageDetailsId (PK)
    ImageSizeId (PK)
    URL
    ...

Image_Details
   ImageDetailsId
   ...

Image_Sizes (where this table is relatively static - small, medium, large..)
   ImageSizeID
   ... (width? height? etc?)
于 2012-09-15T18:24:43.123 回答