Selection and optimization of spatial index (GiST, BRIN, R-Tree) - Aliyun RDS PostgreSQL Best Practice

Label PostgreSQL, Greenplum, PostGIS, GiST, R-Tree, BRIN, Relevance, Grid, BOX, K-Mean background Search requirements for spatial data usually include: 1. Plane, three-dimensional and multi-dimensional objects intersect, disjoint and adjacent in geometry. 2. The orientation judgment of plane, three-dimensional and multi-dimensional objects ( ...

Posted on Fri, 21 Dec 2018 19:06:06 -0800 by r4r4

leetcode 4——Median of Two Sorted Arrays

It's a difficult problem. I've been working on it for a day after reading other people's code. Record ideas for problem solving. The first thing is to distinguish the median, not the average! This problem is to find the median, if the sequence is odd, then directly take the middle, if even, then take the average of the two numbers in the midd ...

Posted on Thu, 20 Dec 2018 09:57:04 -0800 by bluntster

Scaffolding Template on Asp.Net Core Razor Page

Scaffolding Template Intro We know that in Asp.Net MVC, if you use EF's DBC ontext, you can add controllers containing views through the right-click solution-add controllers-add controllers in vs, and then vs will automatically generate the corresponding CURD controllers and views according to the Model you choose. This is called ASP.NET Scaffo ...

Posted on Wed, 19 Dec 2018 22:33:05 -0800 by Liam-PHP

Akka (22): Stream: Real-time Manipulation: Dynamic Pipeline Connection - MergeHub, Broadcast Hub and Partition Hub

In reality, we often encounter the scenario that there is a fixed data source Source, we want to connect any number of downstream receivers subscriber according to the running state of the program, or I need to push multiple data to a fixed data stream terminal Sink when the program runtime runs. This involves dynamically connecting the data fl ...

Posted on Wed, 19 Dec 2018 05:06:05 -0800 by gmann001

Java 8-2-Lambda Expressions Actual-Simplified Map Sorting by Value Value Values

In the previous lecture, we focused on some basic knowledge and basic use of expressions. Today, we will take a real fight to simplify the ranking of Map Value values. In the past, our approach is as follows:   /** * * Map Sort by value; * * @param map * @return */ public static <K, V extends Comparable ...

Posted on Tue, 18 Dec 2018 20:18:03 -0800 by qt4u

Using echartsjs to realize bidirectional interaction between scatter plot and table table, and to realize echarts from table data, and to customize echarts prompt content

I have been studying echarts for some time. Today I will share some tips about echarts. Although it looks simple, it is tedious to do, but it is very practical. In a large page, the table table table is on the left and echarts scatter plot is on the right. Requirement 1 implements that all scatters in echarts are taken from the data in the tabl ...

Posted on Mon, 17 Dec 2018 21:12:04 -0800 by obscurr

Canvas&Paint Knowledge Carding (2) - Canvas Preservation and Recovery

I. Signs Relating to Canvas Preservation Before we understand Canvas's preservation, let's first look at the definitions of the tags associated with preservation, which define the type of preservation. These tags are defined in Canvas.java, and there are six tags in total. /** * Restore the current matrix when restore() is called. */ ...

Posted on Mon, 17 Dec 2018 18:33:03 -0800 by riddlejk

iOS on Common Crypto Encryption II (Common Cryptor AES | DES | 3DES | CAST | BlowFish)

In the last part Summary The general content of each file in CommonCrypto is summarized in this paper. Then the concrete use and related content of the first file CommonCryptor are described in detail below. For example code, go to Github CommonCrypto Download. CommonCryptor Apple's official description of Common Cryptor files is a ...

Posted on Mon, 17 Dec 2018 17:21:04 -0800 by TransmogriBenno

You Don't Know JS (C) -- Part I

type value Native Methods Mandatory Type Conversion grammar type 1. JavaScript has seven built-in types: null, undefined, boolean, number, string, object, and symbol, which can be viewed using the typeof operator. 2. Variables are typeless, but they hold typed values. Types define the behavioral characteristics of ...

Posted on Mon, 17 Dec 2018 03:57:05 -0800 by hawleyj

bzoj2253 [2010 Beijing wc] carton stack (CDQ+dp)

Description Factory P is a factory that produces cartons. After manually inputting three parameters n p a, the carton production line can automatically produce three side lengths as follows (a mod P,a^2 mod p,a^3 mod P) (a^4 mod p,a^5 mod p,a^6 mod P) …. (a^(3n-2) mod p,a^(3n-1) mod p,a^(3n) mod p) n cartons. In order to save space, these ...

Posted on Mon, 17 Dec 2018 00:03:04 -0800 by edg322