【Neo4j查询优化系列】在ORDER BY中使用节点属性索引提高排序性能

用Multisim仿真AD630锁定放大器:从2012年电赛A题实战到避坑指南 本文详细介绍了如何使用Multisim仿真AD630锁定放大器,从2012年电赛A题实战出发,提供完整的电路搭建、参数优化及避坑指南。重点解析AD630的开关调制架构和双相位检测的工程实现,帮助读者在强噪声背景下有效提取微弱信号,提升电子设计竞赛和工程实践中的信号处理能力。 阅读详情

在neo4j 3.5版本中,增加了对ORDER BY的优化,可以通过本地数据库索引(Native Index)提高排序效率。对于有百万或更多节点的集合,排序性能提高会很显著。

在查询中,若要利用这一特性,具体方法如下:

1、为节点属性定义本地索引: CREATE INDEX ON :LABEL(Property)

属性值的类型可以是任何基本类型,但是Point类型除外。

2、在Cypher查询中对建立索引的节点属性显式使用下面任何过滤条件之一:

  • 相等 =
  • 区间:> 或 <
  • STARTS WITH或ENDS WITH
  • 包含:CONTAINS 注意:过滤条件中必须包含有类型的值,这样Cypher编译器才会查找是否有数据库索引可以使用。具体例子见下文。

3、在ORDER BY中对建立索引的节点属性进行排序。

如果Cypher编译器能够使用索引对ORDER BY进行优化,那么EXPLAIN时会看到相应的操作符(operator):

  • NodeIndexContainsScan
  • NodeIndexSeekByRange 而不会再看到Sort、Top操作符。

否则,只会看到在内存中排序相关的操作符:

  • Sort
  • Top

例子如下。模型是只包含一种标签Account的节点,其属性有acctid, acctNo, id和ifsc(无索引)。

// 查看已创建的索引

Indexes

    ON :Account(acctNo) ONLINE
    ON :Account(acctid) ONLINE
    ON :Account(id) ONLINE

/

An example: 2D immersed boundary lattice Boltzmann method code--By Timm Krüger.2011. //谢谢Timm Krüger大佬的代码。 还是老样子,有啥问题Feel free to tell us~毕竟群众力量大嘛~QQ群:293267908。 // 话不多说,上干货! // ISBN 978-3-319-44649-3 (Electronic) // 978-3-319-44647-9 (Print) // http://www.springer.c... 阅读详情

相关推荐

多元相关性分析_PAST:最简便易用的统计学分析软件教程目录

欢迎来到PAST的世界!本教程并不是将PAST的所有功能均进行详细介绍,而只是挑选与生物、医学、微生物研究相关的统计学分析内容进行讲述。根据PAST内各项分析的标签分类,将该教程具体设置如下:PAST软件介绍PAST的基本信息数据的输入和修改数据的转换和标准化图像绘制 (Plot标签)点线图和直方图散点图条形图和箱须图饼图堆叠条形图三元相图气泡图单变量统计学分析 (Univariate标...

weixin_39605706的博客 3155

从镜头到像素:深入解析Camera、Sensor与V4L2的协同工作流

本文深入解析了摄像头从物理成像到软件控制的完整工作流。详细介绍了镜头、传感器(Sensor)与V4L2框架的协同机制,涵盖光电转换、同步信号、ISP图像处理等核心环节,并通过实战演示了如何使用v4l2-ctl工具进行调试,为嵌入式开发和驱动调试提供系统指南。

weixin_29230805的博客 389

计算机网络自顶向下(第八版)第一章课后习题

电路交换网络具有以下优点:资源独占性,在建立连接时,电路交换网络为通信双方独占一条物理路径,不会受到其他用户的影响。低时延,由于建立了专用路径,数据传输时延较小,适合对时延敏感的应用,如实时语音和视频通信。数据链路层:提供节点之间可靠的数据传输,主要任务是错误检测和纠正,以及数据帧的传输和访问控制。移动蜂窝网络:如4G LTE和5G,通过移动基站提供的无线信号实现移动设备的互联网接入。网络层:负责数据包的路由和转发,主要任务是通过网络选择最佳路径,进行流量控制和拥塞控制。手机,服务器,路由器,电脑;

hiahiakk的博客 2255

目标检测数据集 第069期-基于yolo标注格式的玻璃清洁状态检测数据集(含免费分享)

但这类技术的落地,离不开大量标注规范、场景丰富的数据集作为算法训练的支撑,玻璃清洁状态检测数据集的出现,正是为了满足这一市场与技术需求。在高校与科研机构的计算机视觉研究中,该数据集可作为基础研究素材,用于探索物体状态识别的算法优化方向,比如针对玻璃这类透明物体的检测算法改进,或是小样本场景下的状态识别研究。通过摄像头采集车窗、挡风玻璃的图像,算法自动检测玻璃清洁度,若识别到脏污影响视线,及时提醒运维人员清洁,避免因玻璃脏污引发的安全事故,提升交通出行的安全性。

深度学习算法工程师,专注于前沿算法研究与实战应用。在这里,我将分享深度学习领域的实战经验、优质数据集资源以及最新论文解读与精度分析,旨在与广大技术爱好者共同探索人工智能的奥秘,助力技术成长与创新。 128

R语言 Chow Test

Chow 测试用于测试不同数据集上的两个不同回归模型中的系数是否相等。 该测试通常用于计量经济学领域,使用时间序列数据来确定数据在某个时间点是否存在结构性中断。 本教程提供了如何在 R 中执行 Chow 测试的分步示例 首先,我们将创建一些假数据: #create data data <- data.frame(x = c(1, 1, 2, 3, 4, 4, 5, 5, 6, 7, 7, 8, 8, 9, 10, 10, 11, 12, 12, 13,

Mrrunsen的博客 1946

AUTOSAR AP——SM模块

对AUTOSAR AP中状态管理模块SM,从模块定义、总结等多方面进行了介绍。

weixin_43627682的博客 284

innovus:像ICC2一样设置placement label

ICC2有placement label/placement rule功能,能控制各种类型cell 之间的spacing规则,包括top和bottom edge的spacing。innovus也有相同的功能,以下示例方便大家了解用法。我们需要给所有OAI* cell之间设置一个spacing rule,让他们不要上下或者挨着。效果如下图,这个spacing指的是同一边的间距,不是cell间距。我正在「拾陆楼」和朋友们讨论有趣的话题,你⼀起来吧?

m0_61544122的博客 833

SFT看这一篇就够了!万字长文:监督微调(Supervised Fine-Tuning, SFT)技术全解析【从理论到实战】

大家好,我是大 F,深耕AI算法十余年,互联网大厂技术岗。分享AI算法干货、技术心得。欢迎关注,一起探索技术的无限可能!

大F子的智能小课 712

深度学习工具包 DeepLearningToolbox

深度学习工具包Deprecation notice.-----This toolbox is outdated and no longer maintained.There are much better tools available for deep learning than this toolbox, e.g. [Theano](http://deeplearning.net/software/theano/), [torch](http://torch.ch/) or [tensorflow](http://www.tensorflow.org/)I would suggest you use one of the tools mentioned above rather than use this toolbox.Best, Rasmus.DeepLearnToolbox================A Matlab toolbox for Deep Learning.Deep Learning is a new subfield of machine learning that focuses on learning deep hierarchical models of data.It is inspired by the human brain's apparent deep (layered, hierarchical) architecture.A good overview of the theory of Deep Learning theory is[Learning Deep Architectures for AI](http://www.iro.umontreal.ca/~bengioy/papers/ftml_book.pdf)For a more informal introduction, see the following videos by Geoffrey Hinton and Andrew Ng.* [The Next Generation of Neural Networks](http://www.youtube.com/watch?v=AyzOUbkUf3M) (Hinton, 2007)* [Recent Developments in Deep Learning](http://www.youtube.com/watch?v=VdIURAu1-aU) (Hinton, 2010)* [Unsupervised Feature Learning and Deep Learning](http://www.youtube.com/watch?v=ZmNOAtZIgIk) (Ng, 2011)If you use this toolbox in your research please cite [Prediction as a candidate for learning deep hierarchical models of data](http://www2.imm.dtu.dk/pubdb/views/publication_details.php?id=6284)```@MASTERSTHESIS\{IMM2012-06284, author = "R. B. Palm", title = "Prediction as a candidate for learning deep hierarchical models of data", year = "2012",}```Contact: rasmusbergpalm at gmail dot comDirectories included in the toolbox-----------------------------------`NN/` - A library for Feedforward Backpropagation Neural Networks`CNN/` - A library for Convolutional Neural Networks`DBN/` - A library for Deep Belief Networks`SAE/` - A library for Stacked Auto-Encoders`CAE/` - A library for Convolutional Auto-Encoders`util/` - Utility functions used by the libraries`data/` - Data used by the examples`tests/` - unit tests to verify toolbox is workingFor references on each library check REFS.mdSetup-----1. Download.2. addpath(genpath('DeepLearnToolbox'));Example: Deep Belief Network---------------------```matlabfunction test_example_DBNload mnist_uint8;train_x = double(train_x) / 255;test_x = double(test_x) / 255;train_y = double(train_y);test_y = double(test_y);%% ex1 train a 100 hidden unit RBM and visualize its weightsrand('state',0)dbn.sizes = [100];opts.numepochs = 1;opts.batchsize = 100;opts.momentum = 0;opts.alpha = 1;dbn = dbnsetup(dbn, train_x, opts);dbn = dbntrain(dbn, train_x, opts);figure; visualize(dbn.rbm{1}.W'); % Visualize the RBM weights%% ex2 train a 100-100 hidden unit DBN and use its weights to initialize a NNrand('state',0)%train dbndbn.sizes = [100 100];opts.numepochs = 1;opts.batchsize = 100;opts.momentum = 0;opts.alpha = 1;dbn = dbnsetup(dbn, train_x, opts);dbn = dbntrain(dbn, train_x, opts);%unfold dbn to nnnn = dbnunfoldtonn(dbn, 10);nn.activation_function = 'sigm';%train nnopts.numepochs = 1;opts.batchsize = 100;nn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.10, 'Too big error');```Example: Stacked Auto-Encoders---------------------```matlabfunction test_example_SAEload mnist_uint8;train_x = double(train_x)/255;test_x = double(test_x)/255;train_y = double(train_y);test_y = double(test_y);%% ex1 train a 100 hidden unit SDAE and use it to initialize a FFNN% Setup and train a stacked denoising autoencoder (SDAE)rand('state',0)sae = saesetup([784 100]);sae.ae{1}.activation_function = 'sigm';sae.ae{1}.learningRate = 1;sae.ae{1}.inputZeroMaskedFraction = 0.5;opts.numepochs = 1;opts.batchsize = 100;sae = saetrain(sae, train_x, opts);visualize(sae.ae{1}.W{1}(:,2:end)')% Use the SDAE to initialize a FFNNnn = nnsetup([784 100 10]);nn.activation_function = 'sigm';nn.learningRate = 1;nn.W{1} = sae.ae{1}.W{1};% Train the FFNNopts.numepochs = 1;opts.batchsize = 100;nn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.16, 'Too big error');```Example: Convolutional Neural Nets---------------------```matlabfunction test_example_CNNload mnist_uint8;train_x = double(reshape(train_x',28,28,60000))/255;test_x = double(reshape(test_x',28,28,10000))/255;train_y = double(train_y');test_y = double(test_y');%% ex1 Train a 6c-2s-12c-2s Convolutional neural network %will run 1 epoch in about 200 second and get around 11% error. %With 100 epochs you'll get around 1.2% errorrand('state',0)cnn.layers = { struct('type', 'i') %input layer struct('type', 'c', 'outputmaps', 6, 'kernelsize', 5) %convolution layer struct('type', 's', 'scale', 2) %sub sampling layer struct('type', 'c', 'outputmaps', 12, 'kernelsize', 5) %convolution layer struct('type', 's', 'scale', 2) %subsampling layer};cnn = cnnsetup(cnn, train_x, train_y);opts.alpha = 1;opts.batchsize = 50;opts.numepochs = 1;cnn = cnntrain(cnn, train_x, train_y, opts);[er, bad] = cnntest(cnn, test_x, test_y);%plot mean squared errorfigure; plot(cnn.rL);assert(er<0.12, 'Too big error');```Example: Neural Networks---------------------```matlabfunction test_example_NNload mnist_uint8;train_x = double(train_x) / 255;test_x = double(test_x) / 255;train_y = double(train_y);test_y = double(test_y);% normalize[train_x, mu, sigma] = zscore(train_x);test_x = normalize(test_x, mu, sigma);%% ex1 vanilla neural netrand('state',0)nn = nnsetup([784 100 10]);opts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samples[nn, L] = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.08, 'Too big error');%% ex2 neural net with L2 weight decayrand('state',0)nn = nnsetup([784 100 10]);nn.weightPenaltyL2 = 1e-4; % L2 weight decayopts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex3 neural net with dropoutrand('state',0)nn = nnsetup([784 100 10]);nn.dropoutFraction = 0.5; % Dropout fraction opts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex4 neural net with sigmoid activation functionrand('state',0)nn = nnsetup([784 100 10]);nn.activation_function = 'sigm'; % Sigmoid activation functionnn.learningRate = 1; % Sigm require a lower learning rateopts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex5 plotting functionalityrand('state',0)nn = nnsetup([784 20 10]);opts.numepochs = 5; % Number of full sweeps through datann.output = 'softmax'; % use softmax outputopts.batchsize = 1000; % Take a mean gradient step over this many samplesopts.plot = 1; % enable plottingnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex6 neural net with sigmoid activation and plotting of validation and training error% split training data into training and validation datavx = train_x(1:10000,:);tx = train_x(10001:end,:);vy = train_y(1:10000,:);ty = train_y(10001:end,:);rand('state',0)nn = nnsetup([784 20 10]); nn.output = 'softmax'; % use softmax outputopts.numepochs = 5; % Number of full sweeps through dataopts.batchsize = 1000; % Take a mean gradient step over this many samplesopts.plot = 1; % enable plottingnn = nntrain(nn, tx, ty, opts, vx, vy); % nntrain takes validation set as last two arguments (optionally)[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');```[![Bitdeli Badge](https://d2weczhvl823v0.cloudfront.net/rasmusbergpalm/deeplearntoolbox/trend.png)](https://bitdeli.com/free "Bitdeli Badge")

复分析 阿尔福斯(Ahlfors) 第三版答案 英文

答案分为十章,有部分习题没有答案,全英文复分析阿尔福斯(Ahlfors) 第三版答案

迈瑞BS系列全自动生化分析仪LIS协议接口手册(内含HL7和ASTM)

迈瑞BS系列全自动生化分析仪LIS协议接口手册,内含HL7和ASTM)

ssm框架搭建

这个是一个在idea上成功跑起来的ssm框架项目,保存在这里方便以后使用直接下载

上一篇: Gartner 2019年关于数据分析和数据库的最新预测:图数据库未来年增长率会在100%
下一篇: 【Neo4j查询优化系列】如何快速统计节点的关系数
俞博士
俞博士 领域专家: 数据库技术领域 领域专家: 数据库技术领域 业界专家认证 业界专家认证
博客等级 码龄9年 2326粉丝 72原创
评论
成就一亿技术人!
拼手气红包6.0元
还能输入1000个字符
 
 条评论被折叠 查看
添加红包

请填写红包祝福语或标题

个

红包个数最小为10个

元

红包金额最低5元

当前余额3.43元 前往充值 >
需支付:10.00元
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付元
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值