merge

CodeMirror.MergeView

由 青春壹個敷衍的年華 提交于 2020-02-03 07:00:29
最近项目上需要实现2个文本的比较展示功能，找了一圈发现 CodeMirror.MergeView 自带这个功能，其实里面用的diff插件是Google的 diff-match-patch ，在github的星星还蛮多，就用选择这个插件了。 下面写个demo以便备忘。 安装依赖 npm install codemirror npm install diff-match-patch 完整代码 < template > < div id = " view " > </ div > </ template > < script > import CodeMirror from 'codemirror' import 'codemirror/lib/codemirror.css' import 'codemirror/addon/merge/merge.js' import 'codemirror/addon/merge/merge.css' import DiffMatchPatch from 'diff-match-patch' window . diff_match_patch = DiffMatchPatch window . DIFF_DELETE = - 1 window . DIFF_INSERT = 1 window . DIFF_EQUAL = 0 export

MapReduce——shuffle

由 喜欢而已 提交于 2020-02-03 04:20:29
Shuffle 过程是 MR 的一个核心。 简答了解 Shuffle 的作用: 需求场景： 　　在集群环境下，Map task和Reduce task运行在不同的节点上，这个情况下Reduce执行时需要跨节点从其他节点上拉取Map task的输出结果。如果集群上又很多任务在运行，会在运行时消耗很严重的网络资源（这属于正常现象），这种现象无法改变，只能最大化的减少资源的消耗。在数据拉取过程中怎么改变？ 　　1.完整的从Map task 端拉取数据到Reduce端 　　2.在跨节点拉取数据时，尽可能减少对带宽的不必要消耗 　　3.减少磁盘IO对Task的影响 shuffle在Map阶段的操作： 　　整个流程主要分四部：每个map task都有一个内存的缓冲区，存储着map的输出结果。当缓存区快满的时候需要把缓存区的数据以一个临时文件的方式存储放在 磁盘 。当整个map task结束之后再对磁盘中map task产生的文件进行合并，生成最终的输出文件，等待Reduce的拉取。 map阶段只能做 加1 的相加操作 把Map输出结果写入到文件，把key value 进行分组相加 　　内存缓存区默认 100MB 。如果 map task 的输出结果大于 100M 的时候可能会撑爆内存。所以有一定情况下把临时数据 ( 内存缓存区的数据 ) 写入到磁盘。重新利用这个这块缓存区。内存写入磁盘的过程叫

浅谈MapReduce工作机制

由 被刻印的时光 ゝ 提交于 2020-02-03 03:52:15
1.MapTask工作机制 　　整个map阶段流程大体如上图所示。简单概述：input File通过getSplits被逻辑切分为多个split文件，通通过RecordReader(默认使用lineRecordReader)按行读取内容给map(用户自己实现的map方法)，进行处理，数据被map处理结束之后交给OutputCollector收集器，对其结果key进行分区(默认使用hash分区)，然后写入buffer，每个map task 都有一个内存缓冲区，存储着map的输出结果，当缓冲区快满的时候需要将缓冲区的数据以一个临时文件的方式存放到磁盘，当整个map task结束后再对磁盘中这个map task产生的所有临时文件做合并，生成最终的正式输出文件，然后等待reduce task来拉数据。 详细步骤： 1.首先， 读取数据组件 InputFormat (默认TextInputFormat)会通过 getSplits 方法对输入目录中文件进行 逻辑切片规划 得到splits，有多少个split就对应启动多少个MapTask。split与block的对应关系可能是一对多，默认是一对一。 2.将输入文件切分为splits之后，由 RecordReader 对象(默认LineRecordReader)进行读取，以"\n"作为分隔符，读取一行数据返回<key,value>

Merge data based on nearest date R

由 雨燕双飞 提交于 2020-02-03 03:00:20
问题 How do I jeft.join 2 data frames based on the nearest date? I currently have the script written so that it joins by the exact date, but I would prefer to do it by nearest date in case there is not an exact match. This is what I currently have: MASTER_DATABASE <- left_join(ptnamesMID, CTDB, by = c("LAST_NAME", "FIRST_NAME", "Measure_date" = "VISIT_DATE")) 回答1: The rolling joins in the data.table have a parameter roll = "nearest" which does propably what the OP expects. Unfortunately, the OP

Merge data based on nearest date R

由 我的梦境 提交于 2020-02-03 02:58:10
问题 How do I jeft.join 2 data frames based on the nearest date? I currently have the script written so that it joins by the exact date, but I would prefer to do it by nearest date in case there is not an exact match. This is what I currently have: MASTER_DATABASE <- left_join(ptnamesMID, CTDB, by = c("LAST_NAME", "FIRST_NAME", "Measure_date" = "VISIT_DATE")) 回答1: The rolling joins in the data.table have a parameter roll = "nearest" which does propably what the OP expects. Unfortunately, the OP

OCaml mergesort and time

由 白昼怎懂夜的黑 提交于 2020-02-02 18:19:47
问题 I created a function (mergesort) in ocaml but when I use it, the list is inverted. In addition, I want to calculate the time the system takes to do the calculation, how can I do it? let rec merge l x y = match (x,y) with | ([],_) -> y | (_,[]) -> x | (h1::t1, h2::t2) -> if l h1 h2 then h1::(merge l t1 y) else h2::(merge l x t2);; let rec split x y z = match x with | [] -> (y,z) | x::resto -> split resto z (x::y);; let rec mergesort l x = match x with | ([] | _::[]) -> x | _ -> let (pri,seg) =

OCaml mergesort and time

由 孤人 提交于 2020-02-02 18:19:05
问题 I created a function (mergesort) in ocaml but when I use it, the list is inverted. In addition, I want to calculate the time the system takes to do the calculation, how can I do it? let rec merge l x y = match (x,y) with | ([],_) -> y | (_,[]) -> x | (h1::t1, h2::t2) -> if l h1 h2 then h1::(merge l t1 y) else h2::(merge l x t2);; let rec split x y z = match x with | [] -> (y,z) | x::resto -> split resto z (x::y);; let rec mergesort l x = match x with | ([] | _::[]) -> x | _ -> let (pri,seg) =

Oracle 11g: In PL/SQL is there any way to get info about inserted and updated rows after MERGE DML statement?

由 孤街醉人 提交于 2020-02-02 13:22:40
问题 I would like to know is there any way to receive information in PL/SQL how many rows have been updated and how many rows have been inserted while my PL/SQL script using MERGE DML statement. Let's use Oracle example of merge described here: MERGE example This functionality is used in my function but also I'd like to log information how many rows has beed updated and how many rows have been inserted. 回答1: There is a not a built-in way to get separate insert and update counts, no. SQL%ROWCOUNT

Oracle 11g: In PL/SQL is there any way to get info about inserted and updated rows after MERGE DML statement?

由 若如初见. 提交于 2020-02-02 13:16:55
问题 I would like to know is there any way to receive information in PL/SQL how many rows have been updated and how many rows have been inserted while my PL/SQL script using MERGE DML statement. Let's use Oracle example of merge described here: MERGE example This functionality is used in my function but also I'd like to log information how many rows has beed updated and how many rows have been inserted. 回答1: There is a not a built-in way to get separate insert and update counts, no. SQL%ROWCOUNT

How to merge pandas on string contains?

由 心不动则不痛 提交于 2020-02-02 12:28:43
问题 I have 2 dataframes that I would like to merge on a common column. However the column I would like to merge on are not of the same string, but rather a string from one is contained in the other as so: import pandas as pd df1 = pd.DataFrame({'column_a':['John','Michael','Dan','George', 'Adam'], 'column_common':['code','other','ome','no match','word']}) df2 = pd.DataFrame({'column_b':['Smith','Cohen','Moore','K', 'Faber'], 'column_common':['some string','other string','some code','this code',
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