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How to speed up insertion performance in PostgreSQL

... If you happend to insert colums with UUIDs (which is not exactly your case) and to add to @Dennis answer (I can't comment yet), be advise than using gen_random_uuid() (requires PG 9.4 and pgcrypto module) is (a lot) faster than uuid_generate_v4() =# explain anal...
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内存管理内幕:动态分配选择、折衷和实现 - C/C++ - 清泛网 - 专注C/C++及内核技术

...版本非常类似基本结构,但是它加入了索引,这使得搜索速度更快,并且可以将多个没有被使用块组合为一个大块。它还支持缓存,以便更快地再次使用最近释放内存。 ptmalloc 是 Doug Lea Malloc 一个扩展版本,支持多...
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“21天教你学会C++” - 创意 - 清泛网 - 专注C/C++及内核技术

...,而只需要几天甚至几小时。我在Amazon.com上进行了如下搜索: pubdate: after 1992 and title: days and (title: learn or title: teach yourself) (出版日期:1992年后 and 书名:天 and (书名:学会 or 书名:无师自通)) 我一共得到了248个搜索...
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Rails 4: List of available datatypes

... For Postgres there is additionally a uuid type which can be used as normal field like t.uuid :name... or as primary key like create_table :users, id: :uuid do... or e.g. t.primary_key :id, :uuid, :default => 'uuid_generate_v1()' – TNT ...
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Boost.Asio简单使用(Timer,Thread,Io_service类) - C/C++ - 清泛网 - 专注C/C++及内核技术

...造出void(const boost::asio::error&)形式函数. 注意,这里没有指定boost::asio::placeholders::error占位符,因为这个print成员函数没有接受一个error对象作为参数. timer_.async_wait(boost::bind(&printer::print, this)); 在类折构函数中我们输出最后一...
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Vsphere 6 集群上 安装 oracle rac 遇到共享磁盘故障 - 数据库(内核) - ...

...示 不能访问物理存储 第一次死机 对比互联网上搜索方法对比 发现SCSI总线不一样。 参考文档http://www.doc88.com/p-5416264066182.html 按照网上方法,修改SCSI 控制1总线为LSI Logic 并行。修改好后,开启虚拟机电源...
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Mocking static methods with Mockito

...ception occurred while fetching localhost address", e); return UUID.randomUUID().toString(); } } } My test class: @RunWith(PowerMockRunner.class) @PrepareForTest(SmokeRouteBuilder.class) public class SmokeRouteBuilderTest { @Test public void testSmokeMessageId_exce...
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Add a reference column migration in Rails 4

...cument if someone has the same problem... In my situation I've been using :uuid fields, and the above answers does not work to my case, because rails 5 are creating a column using :bigint instead :uuid: add_reference :uploads, :user, index: true, type: :uuid Reference: Active Record Postgresql UUID...
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从源代码剖析Mahout推荐引擎 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术

...考用户。 近邻算法分为2种: NearestNUserNeighborhood:指定N个数,比如,选出前10最相似用户。 ThresholdUserNeighborhood:指定比例,比如,选择前10%最相似用户。 6. 推荐算法工具集 推荐算法是以Recommender作为基础父类...
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Getting MAC Address

... Python 2.5 includes an uuid implementation which (in at least one version) needs the mac address. You can import the mac finding function into your own code easily: from uuid import getnode as get_mac mac = get_mac() The return value is the mac...