data domain deduplication

Tags: mysql database go heavyBecause the work needs to carry on the data to weigh, therefore does the record, actually is very small white question ....In fact, in terms of data deduplication, the best thing is to design the program and database when the data redundancy is considered, do not insert duplicate

questions raised: M (such as 1 billion int integer, where the number of n is repeated, read into memory, and delete the repeating integer. Problem Analysis: we would have thought about opening up an array of M int integers in computer memory, one bye to read an array of M int, then a one by one comparison value, and finally the deduplication of the data. This is, of course, feasible in dealing with small-sc

Data Deduplication in mysql and bitsCN.com optimization Data Deduplication and optimization in mysql After you change the primary key uid of user_info to the auto-increment id, you forget to set the original primary key uid attribute to unique. as a result, duplicate uid records are generated. To this end, you need t

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 wa

After data deduplication and Optimization in mysql changes the primary key uid of table user_info to the auto-increment id, you forget to set the original primary key uid attribute to unique. As a result, duplicate uid records are generated. To this end, you need to clear the records that are inserted later. You can refer to the attached documents for the basic method. However, because mysql does not suppor

Recently installed a Veeam server, you need to restore some file server information, but the implementation of the task of the following error occurred650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M02/3E/58/wKiom1PHQqOSDTh1AAFT6Q3u6hs815.png "title=" error. PNG "alt=" Wkiom1phqqosdth1aaft6q3u6hs815.png "/>After some research, it is found that this problem is caused by the use of data deduplication

); } } //reduce copies the key from the input to the key of the output data and outputs it directly, paying attention to the type and number of parameters Public Static classReduceextendsReducer{ //Note the type and number of parameters Public voidReduce (Text key, iterablethrowsioexception,interruptedexception{System.out.println ("Reducer ..."); System.out.println ("Key:" +key+ "values:" +values); Context.write (Key,N

1.Data deduplicationSOLR supports data deduplication through the types of Method Describe Md5signature The 128-bit hash is used for replica detection resolution. Lookup3signature A 64-bit hash is used for replica detection resolution. Faster than MD5, with smaller indexes. Textprofilesig

Recently, the de-duplication of data arrays is always encountered during the project process. After multiple modifications to the program, the following is a summary: Data deduplication The Code is as follows: Var zdata = [];Cityaname = result. aname;Isp_cityname = $ ('. isp_cityname' + monitorip_arr[num]).html ();If (zdata [cityanam

Detailed description of MySQL Data deduplication instances Detailed description of MySQL deduplication instances There are two Repeated Records. One is a completely repeated record, that is, all fields are duplicated, and the other is a record with some fields repeated. For the first type of repetition, it is easy to solve. You only need to use the distinct keywo

, original)) {Servlets.writehtml (Response, "true");Return}Check if the database has duplicate namesBoolean exist = service.emailexist (email);if (!exist) {Servlets.writehtml (Response, "true");} else {Servlets.writehtml (response, "false");}*/}Yuan Sheng Backstage:protected void doget (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException {Response.setcontenttype ("Text/html:charset=utf-8");Response.setcharacterencoding ("Utf-8");PrintWriter out= Respons

Tag: equals code uses element delete to perform dev repeat hashTo insert into the database go to weight: 1. Iterate through the list you have read 2. Get the data you need to query before you insert the method into the database, execute the Query method 1 devlist=devicedao.finddevice (Device.getrfid ()); 2 if (Devlist.size () >0) { 3 messagestr = "Duplicate data, please r

)Create Tabletmp_relationship_id as(Select min(ID) asId fromRelationshipGroup bySource,target having Count(*)>1)Create an indexAlter Table Add index name (field name)DeleteDelete from Relationship where not inch (Select from tmp_relationship_id) and inch (Select from relationship)2.2 Quick MethodIn practice, it is found that the above method of removing field duplication, because there is no way to rebuild the index for multiple fields, resulting in large

");3. Test situationTest methodFirst time (unit ms)First time (unit ms)15214ms5735ms2299ms290Ms359ms28ms426ms26msIii. Conclusion1, using ExecuteSQL delete the fastest, the database is the most efficient.2, Deletesearchedrows and ExecuteSQL belong to bulk Delete, better performance.3, the query results deleted, the slowest, if you use this method, set up you immediately modify your program, because you are wasting time.4.The number of small data record

Let's say we have a MongoDB collection, Take this simple set as an example, we need to include how many different mobile phone numbers in the collection, the first thought is to use the DISTINCT keyword, Db.tokencaller.distinct (' Caller '). length If you want to see specific and different phone numbers, then you can omit the length property, since Db.tokencaller.distinct (' Caller ') returns an array of all the mobile phone numbers. However, this approach is sufficient for all situations.

. Rows.Add (_DR. ItemArray); Console.WriteLine ("--------------------table with duplicate data originally----------------------"); _dt. AsEnumerable (). ToList (). ForEach (M={Console.WriteLine (m["ID"]. ToString () +" "+ m["name"]. ToString () +" "+ m["Address"]. ToString ()); }); Console.WriteLine ("--------------------Remove the duplicate table----------------------"); var_compresult = _dt. AsEnumerable (). D

name,address, which requires the result set to be unique for both fieldsSelect Identity (int,1,1) as Autoid, * into #Tmp from TableNameSelect min (autoid) as autoid into #Tmp2 from #Tmp Group by name,autoidSELECT * from #Tmp where autoid on (select Autoid from #tmp2) The last select is the result set that name,address not duplicate (but one more autoid field that can be written when actually writing Omit this column in the SELECT clause) (iv) Duplication of queriesSELECT * FROM tablename where