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什么是ETag？ETag作用有哪些

ETag是HTTP头的一部分，它是一个字符串标识一个web资源的特定版本。它由web服务器生成，用于标识文件的实体标签。ETag可以用来确定同一资源是否已被修改，这在缓存和验证客户端缓存文件是否过期时很有用。ETag的作用如下： 1.缓存控制：在HTTP响应头部中包含ETag可以帮助浏览器缓存和验证资源。如果资源没有发生任何改变，浏览器可以直接从本地缓存中获取资源，而不需要重新从服务器获取。 2.资源验证：如果浏览器的缓存过期或需要更新，它可以使用请求头中的ETag来验证资源是否已被修改。如果资源没有被修改，服务器可以发送一个响应代码为304的响应，告诉浏览器它可以继续使用缓存中的资源。 3.负载均衡：在使用多个Web服务器负载均衡时，ETag可以确保客户端的请求被重定向到与其之前请求相同的服务器。如果不使用ETag，则可能会发生客户端请求一个资源，但它需要从新的服务器获取，即使其他服务器已经有缓存。

Public @ 2023-06-10 23:50:20

百度智能小程序搜索结果出图上线

1.搜索结果出图权益介绍搜索结果中展现图片，一方面可以让搜索用户有更好的浏览体验，同时也可以为搜索结果带来更多点击。现在面对智能小程序推出搜索结果出图权益，允许开发者推荐智能小程序在搜索结果中展示的图片。搜索结果出图的图片样式共分两种，一图样式和三图样式，现阶段一图样式已全量开放，三图样式内测逐渐开放中。2.如何配置搜索结果出图？①代码改造在智能小程序页面开发工具中，在【API】>【开放接口

Public @ 2021-02-12 16:02:02

百度搜索资源平台-提交APP信息，资本冬天不再寒冷

百度搜索资源平台拥有丰富的数据资源和可供提交的APP信息，支持根据业务要求添加APP信息的记录，有助于企业发掘市场，建立新的营销渠道，扩大企业影响力。此外，百度搜索资源平台正在不断提供新的功能支持，可通过资本冬天的帮助来实现不受冷清影响，可以更好的提升企业营收能力，促进企业实现可持续发展。

Public @ 2023-02-24 14:12:17

我的 Sitemap 可以有多大？

单个Sitemap 应该小于 10MB（10,485,759字节），所包含的网址数最多为 50,000 个。如果您网站包含的网址超过 50,000 个或您的 Sitemap 超过 10MB，则需要创建多个 Sitemap 文件，并且需要使用 Sitemap 索引文件。Sitemap 索引文件应该小于 10MB（10,485,759字节），且最多可以包含1000个sitemap。

Public @ 2009-06-06 16:11:56

什么是ETag？ETag作用有哪些

ETag是HTTP协议提供的一种用于判断资源是否发生变化的机制。ETag是一个字符串，由服务器生成，在资源被更新时会发生变化。客户端请求资源时，服务器会将资源的ETag值一起返回，客户端可以缓存资源，并记录ETag值。当客户端再次请求该资源时，会将上次记录的ETag值一同发送给服务器。如果此时服务器返回的ETag值与客户端记录的值相同，就说明资源没有变化，客户端可以直接使用缓存的资源，减少网络请求

Public @ 2023-03-25 23:50:19

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基本文件流程错误 SQL 调试

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[ DB ] CONNECT:[ UseTime:0.026285s ] mysql:dbname=briline.net;host=106.14.77.182;port=3306;charset=utf8
[ SQL ] SHOW COLUMNS FROM `ob_article` [ RunTime:0.018848s ]
[ SQL ] SELECT * FROM `ob_article` WHERE `id` = 8735 LIMIT 1 [ RunTime:0.017646s ]
[ EXPLAIN : array ( 'id' => 1, 'select_type' => 'SIMPLE', 'table' => 'ob_article', 'type' => 'const', 'possible_keys' => 'PRIMARY', 'key' => 'PRIMARY', 'key_len' => '4', 'ref' => 'const', 'rows' => 1, 'extra' => NULL, ) ]
[ SQL ] select * from `ob_article_tongji` where category_id=12 and mark_type='cate' order by times desc limit 15 [ RunTime:0.017880s ]
[ EXPLAIN : array ( 'id' => 1, 'select_type' => 'SIMPLE', 'table' => 'ob_article_tongji', 'type' => 'ALL', 'possible_keys' => NULL, 'key' => NULL, 'key_len' => NULL, 'ref' => NULL, 'rows' => 608, 'extra' => 'Using where; Using filesort', ) ]
[ SQL ] select * from `ob_article_tongji` where category_id=12 and mark_type='tags' order by times desc limit 100 [ RunTime:0.018004s ]
[ EXPLAIN : array ( 'id' => 1, 'select_type' => 'SIMPLE', 'table' => 'ob_article_tongji', 'type' => 'ALL', 'possible_keys' => NULL, 'key' => NULL, 'key_len' => NULL, 'ref' => NULL, 'rows' => 608, 'extra' => 'Using where; Using filesort', ) ]
[ SQL ] select * from `ob_article_tongji` where category_id=12 and mark_type='tags' order by rand() limit 30 [ RunTime:0.018417s ]
[ EXPLAIN : array ( 'id' => 1, 'select_type' => 'SIMPLE', 'table' => 'ob_article_tongji', 'type' => 'ALL', 'possible_keys' => NULL, 'key' => NULL, 'key_len' => NULL, 'ref' => NULL, 'rows' => 608, 'extra' => 'Using where; Using temporary; Using filesort', ) ]
[ SQL ] SELECT * FROM `ob_article` WHERE `id` = 8735 LIMIT 1 [ RunTime:0.017491s ]
[ EXPLAIN : array ( 'id' => 1, 'select_type' => 'SIMPLE', 'table' => 'ob_article', 'type' => 'const', 'possible_keys' => 'PRIMARY', 'key' => 'PRIMARY', 'key_len' => '4', 'ref' => 'const', 'rows' => 1, 'extra' => NULL, ) ]
[ SQL ] update `ob_article` set views=views+1 where id=8735 [ RunTime:0.020159s ]
[ SQL ] SELECT COUNT(*) AS tp_count FROM `ob_article` WHERE `category_id` = 12 AND `cate` = '威海百度搜索资源平台' AND `status` <> -1 LIMIT 1 [ RunTime:0.025070s ]
[ EXPLAIN : array ( 'id' => 1, 'select_type' => 'SIMPLE', 'table' => 'ob_article', 'type' => 'ALL', 'possible_keys' => NULL, 'key' => NULL, 'key_len' => NULL, 'ref' => NULL, 'rows' => 8035, 'extra' => 'Using where', ) ]
[ SQL ] SELECT * FROM `ob_article` WHERE `category_id` = 12 AND `cate` = '威海百度搜索资源平台' AND `status` <> -1 ORDER BY rand() LIMIT 0,2 [ RunTime:0.042657s ]
[ EXPLAIN : array ( 'id' => 1, 'select_type' => 'SIMPLE', 'table' => 'ob_article', 'type' => 'ALL', 'possible_keys' => NULL, 'key' => NULL, 'key_len' => NULL, 'ref' => NULL, 'rows' => 8035, 'extra' => 'Using where; Using temporary; Using filesort', ) ]
[ SQL ] SELECT COUNT(*) AS tp_count FROM `ob_article` WHERE `category_id` = 12 AND `tags` = '威海Sitemap' AND `status` <> -1 LIMIT 1 [ RunTime:0.025041s ]
[ EXPLAIN : array ( 'id' => 1, 'select_type' => 'SIMPLE', 'table' => 'ob_article', 'type' => 'ALL', 'possible_keys' => NULL, 'key' => NULL, 'key_len' => NULL, 'ref' => NULL, 'rows' => 8035, 'extra' => 'Using where', ) ]
[ SQL ] SELECT * FROM `ob_article` WHERE `category_id` = 12 AND `tags` = '威海Sitemap' AND `status` <> -1 ORDER BY rand() LIMIT 0,2 [ RunTime:0.036050s ]
[ EXPLAIN : array ( 'id' => 1, 'select_type' => 'SIMPLE', 'table' => 'ob_article', 'type' => 'ALL', 'possible_keys' => NULL, 'key' => NULL, 'key_len' => NULL, 'ref' => NULL, 'rows' => 8035, 'extra' => 'Using where; Using temporary; Using filesort', ) ]

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