deduplication

Php array element deduplication 1. remove duplicates using the array_unique method To deduplicate array elements, we usually use the array_unique method. this method can be used to deduplicate the elements in the array. 123456 Output: Array( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 [5] => 6 [6] => 7 [7] => 8 [8] => 9)123456789101112 After deduplication, the key values a

// Define an array to store the results after deduplication$ Result = array ();// Read the uid list file$ Fp = fopen('test.txt ', 'r ');While (! Feof ($ fp )){ $ Uid = fgets ($ fp );$ Uid = trim ($ uid );$ Uid = trim ($ uid ,"");$ Uid = trim ($ uid ,"");If ($ uid = ''){ Continue;} // Use uid as the key to check whether the value existsIf (empty ($ result [$ uid]){ $ Result [$ uid] = 1;} }Fclose ($ fp );// Sa

Welcome to the Linux community forum, and interact with 2 million technical staff to enter the GROUPBY statement to implement deduplication query for a certain column. Directly run the preceding statement: selectio_dev_idfromio_infowhere (Tyang1) GROUPBY1; deduplication by io_dev_id. P: add it with ORDERBY and disti. Welcome to the Linux community forum and interact with 2 million technical staff> enter the

Research on Big Data de-duplication in hive inventory table: store incremental table: inre field: 1. p_key remove duplicate primary key 2. w_sort sort by 3.info other information method 1 (unionall + row_number () over): insertoverwritetablelimao_storeselectp_key, sort_wordfrom (selecttmp1. *, row_num Research on Big Data de-duplication in hive inventory table: store incremental table: inre field: 1. p_key remove duplicate primary key 2. w_sort sorting is based on 3. other info information metho

During project development, arrays often contain a lot of repeated content, that is, dirty data removal operations. This article focuses on several methods of array deduplication. For more information, see. 1.According to the principle that keys in js objects are not repeated, the method of removing duplicates from arrays is conceived. The most common thinking is as follows: The Code is as follows: Function distinctArray (arr ){Var obj = {}, temp =

Select * From dc_restaurants; 31 Select distinct (restaurant_name), ID from dc_restaurants; 31 (deduplication will be performed based on the ID and specified ant_name) Select distinct (restaurant_name), ID from dc_restaurantsGroup by comment ant_name; 17 Select distinct ant_name, ID from dc_restaurantsGroup by comment ant_name; 17 -- Deduplication based on a field: 1. Group by (do not pay attention

Summary of deduplication methods for javascript Arrays Summary of deduplication methods for javascript Arrays Array deduplication is a common requirement. We will temporarily consider repeated arrays of the same type. It mainly aims to clarify the ideas and consider the performance. The following methods are available on the Internet. Here is a brief summary. Sum

Three methods and code examples for removing the deduplication of JavaScript Arrays This article mainly introduces three methods and code examples for de-duplicating JavaScript arrays. This article provides the instance Code directly. For more information, see There are many methods to deduplicate arrays. it is unclear which one is the best. So I tested the effect and performance of array deduplication. Tes

Hadoopmapreduce data deduplication assuming we have the following two files, we need to remove duplicate data. File0 [plain] 2012-3-1a2012-3-2b2012-3-3c2012-3-4d2012-3-5a2012-3-6b2012-3-7c2012-3-3cfile1 [plain] 2012-3-1b2012-3-2a2012-3-3b2012-3-4d2012-3- Hadoop mapreduce data deduplication assumes that we have the following two files, and we need to remove duplicate data. File0 [plain] 2012-3-1 a 2012-3-2 B

/// /// List generic deduplication/// /// /// Private void RemoveRepeaterUrl (ref List {For (int I = 0; I {For (int j = (I + 1); j {If (list [j] [ItemID] = list [I] [ItemID]){List. RemoveAt (j); // remove identical itemsI = 0; // deduplication from the beginning. If there are a large number of repeated items in the array, only one deduplication cannot solve the p

Mongodb deduplication, aggregation, query explanation, mongodb Aggregation I recently learned about mongodb and some people understand it: 1. deduplication Repeated template. getCollection (collectionName). distinct () returns the list set, which is the result after deduplication. 2. Aggregation Aggregation aggregation = Aggregation. newAggregation (Criteri

PHP two-dimensional array deduplication example analysis This article analyzes the PHP two-dimensional array deduplication method. We will share this with you for your reference. The details are as follows: We all know that the one-dimensional array is used to reuse the system function array_unique ($ arr) Then today I used a two-dimensional array, and I also want to remove duplicates. Baidu has a lot of d

: This article mainly introduces the PHP two-dimensional array deduplication method (retaining each key value while removing repeated items)-The uniqueness of the two-dimensional array, if you are interested in the PHP Tutorial, refer. Deduplicate the following two-dimensional array: $arr = array( '0'=>array( 'name'=>'james', 'age'=>30, ), '1'=>array( 'name'

PHP two-dimensional array deduplication method (preserving individual key values while removing duplicates)--uniqueness of two-dimensional arrays For the following two-dimensional arrays, it is required to be de-weighed: $arr = Array (' 0 ' =>array ( ' name ' = ' James ', ' age ' =>30, ), ' 1 ' =>array ( ' name ' = > ' Susu ', ' age ' =>2

1) Open the Add Server role and function wizard and click Next 650) This. width = 650; "Title =" clip_image002 "style =" border-top: 0px; border-Right: 0px; border-bottom: 0px; border-left: 0px; display: inline "border =" 0 "alt =" clip_image002 "src =" http://img1.51cto.com/attachment/201410/9/1559738_1412821674fued.jpg "" 558 "Height =" 395 "/> 2) Check the data deduplication function. 650) This. width = 650; "Title =" clip_image004 "style =" bor

Javascript array deduplication, javascript Array // Remove the Array of numeric elements function sortnum (a, B) {return a-B;} Array. prototype. unique1 = function () {this. sort (sortnum); var newnumbers = [this [0]; for (var I = 0; I Javascript array deduplication Arr is an array to be duplicated, and ret is a new array obtained after deduplication. hash is e

I think we should first perform array deduplication when practicing ACM in nine degrees, because most of my work is written in PHP. Code In PHP, only one array_diff () function can be used to deduplicate arrays. However, in C language, I don't have any ready-made API functions that can be called by me, So I implemented Algorithm Array deduplication, but this algorithm has obvious defects. I will first dis

String output_path= "HDFS://MASTER:9000/QUCHONG/QC";Static class Mymapper extends mapperprivate static text line=new text (); Each row as a dataprotected void Map (Object key, Text value, Context context) throws IOException, interruptedexception{Line=value;Context.write (Line,new Text (",")); Key is unique, and as a data, the implementation of deduplication}}Static class Myreduce extends reducerprotected void reduce (Text key,iterableContext.write (k

Data deduplication can reduce disk usage, but it may also increase IO if used improperly, and this feature will block the hard disk, so it is difficult to defragment when the hard disk is high, so it is sometimes necessary to disable deduplication and de-duplicate data optimization. This can be done in the following ways: (Attached: I disable it because of the various non-responsive running VirtualBox disk)

PHP array deduplication? Array deduplication $ Term = array_column ($ grade, 'condition'); $ term = array_flip ($ term); print_r ($ term ); Effect: Principle: Array_flip (): The function returns an inverted array. if the same value appears multiple times, the last key name will be used as its value, and all other key names will be lost. If the data type of the value in the original array is not a