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什么是ETag？ETag作用有哪些

ETag（Entity Tag）是HTTP协议中的一个头部字段，用于标识资源的某个版本。 ETag的作用主要有以下几点： 1. 缓存控制：当客户端请求一个资源时，服务器可以通过ETag来判断资源是否发生了变化。如果ETag与客户端提供的If-None-Match头字段一致，说明资源没有发生变化，服务器可以返回一个304 Not Modified状态码，告诉客户端可以使用本地缓存的副本，从而节省带宽和响应时间。 2. 并发控制：当多个客户端并发请求修改同一个资源时，服务器可以使用ETag来判断客户端提交的数据是否仍然是有效的，从而避免冲突和重复提交。 3. 断点续传：当客户端请求下载一个大文件时，服务器可以在响应中包含ETag，当客户端在下载过程中中断，再次请求时可以通过包含If-Match头字段以及之前获取到的ETag来恢复下载。总的来说，ETag可以帮助服务器和客户端更有效地处理缓存和并发请求，提升系统的性能和用户体验。

Public @ 2023-07-23 06:50:22

百度搜索资源平台-落地页视频转存

百度搜索资源平台是一个集成了多种搜索资源的平台，用户可以通过该平台搜索网络上的各种资源，包括网页、图片、视频、文档等等。如果您要落地页视频转存，您可以按照以下步骤进行操作： 1. 打开百度搜索资源平台的官方网站（www.baidu.com），在搜索框中输入想要下载的视频的相关关键词，点击搜索按钮。 2. 在搜索结果页面中，找到您想要下载的视频的链接，点击进入视频的详情页。 3. 在视频详情页

Public @ 2023-06-30 03:50:09

站长反馈中心6月3日-6月9日问题反馈

暂无站长反馈中心6月3日-6月9日的问题反馈。

Public @ 2023-05-30 02:00:04

XML格式中，“priority”提示会影响结果排名吗？

不会。Sitemap 中的“priority”提示只是说明该网址相对于您自己网站上其他网址的重要性，并不会影响网页在搜索结果中的排名。

Public @ 2012-07-30 16:11:53

sitemap提交后，多久能被百度抓取？

sitemap数据提交后，一般在1小时内会被百度处理。处理完成的时间视文件大小而定。

Public @ 2012-11-22 16:11:57

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基本文件流程错误 SQL 调试

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[ DB ] CONNECT:[ UseTime:0.026130s ] mysql:dbname=briline.net;host=106.14.77.182;port=3306;charset=utf8
[ SQL ] SHOW COLUMNS FROM `ob_article` [ RunTime:0.018448s ]
[ SQL ] SELECT * FROM `ob_article` WHERE `id` = 9799 LIMIT 1 [ RunTime:0.017508s ]
[ 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:0.017796s ]
[ 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:0.018053s ]
[ 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:0.018182s ]
[ 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` = 9799 LIMIT 1 [ RunTime:0.017444s ]
[ 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+2 where id=9799 [ RunTime:0.020494s ]
[ 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:0.024451s ]
[ EXPLAIN : array ( 'id' => 1, 'select_type' => 'SIMPLE', 'table' => 'ob_article', 'type' => 'ALL', 'possible_keys' => NULL, 'key' => NULL, 'key_len' => NULL, 'ref' => NULL, 'rows' => 9562, '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:0.046222s ]
[ EXPLAIN : array ( 'id' => 1, 'select_type' => 'SIMPLE', 'table' => 'ob_article', 'type' => 'ALL', 'possible_keys' => NULL, 'key' => NULL, 'key_len' => NULL, 'ref' => NULL, 'rows' => 9562, '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:0.024121s ]
[ EXPLAIN : array ( 'id' => 1, 'select_type' => 'SIMPLE', 'table' => 'ob_article', 'type' => 'ALL', 'possible_keys' => NULL, 'key' => NULL, 'key_len' => NULL, 'ref' => NULL, 'rows' => 9562, '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:0.036990s ]
[ EXPLAIN : array ( 'id' => 1, 'select_type' => 'SIMPLE', 'table' => 'ob_article', 'type' => 'ALL', 'possible_keys' => NULL, 'key' => NULL, 'key_len' => NULL, 'ref' => NULL, 'rows' => 9562, 'extra' => 'Using where; Using temporary; Using filesort', ) ]

0.503591s

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