Search Results

Search found 11543 results on 462 pages for 'partition wise join'.

Page 366/462 | < Previous Page | 362 363 364 365 366 367 368 369 370 371 372 373  | Next Page >

• Composite Primary and Cardinality

  - by srini.venigalla

  I have some questions on Composite Primary Keys and the cardinality of the columns. I searched the web, but did not find any definitive answer, so I am trying again. The questions are: Context: Large (50M - 500M rows) OLAP Prep tables, not NOSQL, not Columnar. MySQL and DB2 1) Does the order of keys in a PK matter? 2) If the cardinality of the columns varies heavily, which should be used first. For example, if I have CLIENT/CAMPAIGN/PROGRAM where CLIENT is highly cardinal, CAMPAIGN is moderate, PROGRAM is almost like a bitmap index, what order is the best? 3) What order is the best for Join, if there is a Where clause and when there is no Where Clause (for views) Thanks in advance.

  Read the article

• How to keep Hibernate mapping use under control as requirements grow

  - by David Plumpton

  I've worked on a number of Java web apps where persistence is via Hibernate, and we start off with some central class (e.g. an insurance application) without any time being spent considering how to break things up into manageable chunks. Over time as features are added we add more mappings (rates, clients, addresses, etc.) and then amount of time spent saving and loading an insurance object and everything it connects to grows. In particular you get close to a go-live date and performance testing with larger amounts of data in each table is starting to demonstrate that it's all too slow. Obviously there are a number of ways that we could attempt to partition things up, e.g. map only the client classes for the client CRUD screens, etc., which would have been better to get in place earlier rather than trying to work it in at the end of the dev cycle. I'm just wondering if there are recommendations about ways to handle/mitigate this.

  Read the article

• Get a DB result with a value between two columns values

  - by vitto

  Hi, I have a database situation where I'd like to get a user profile row by a user age range. this is my db: table_users username age email url pippo 15 [email protected] http://example.com pluto 33 [email protected] http://example.com mikey 78 [email protected] http://example.com table_profiles p_name start_age_range stop_age_range young 10 29 adult 30 69 old 70 inf I use MySQL and PHP but I don't know if there is some specific tacnique to do this and of course if it's possible. # so something like: SELECT * FROM table_profiles AS profiles INNER JOIN table_users AS users # can I do something like this? ON users.age IS BETWEEN profiles.start_age_range AND profiles.stop_age_range

  Read the article

• How to manually verify a user against the asp.net memberhip database

  - by Ekk

  I would like to know how I can verify a user's credential against an existing asp.net membership database. The short story is that we want provide single sign on access. So what I've done is to connect directly to the membership database and tried to run a sql query against the aspnet_Membership table: private bool CanLogin(string userName, string password) { // Check DB to see if the credential is correct try { string passwordHash = FormsAuthentication.HashPasswordForStoringInConfigFile(password, "SHA1"); string sql = string.Format("select 1 from aspnet_Users a inner join aspnet_Membership b on a.UserId = b.UserId and a.applicationid = b.applicationid where a.username = '{0}' and b.password='{1}'", userName.ToLowerInvariant(), passwordHash); using (SqlConnection sqlConn = new SqlConnection(ConfigurationManager.ConnectionStrings["LocalSqlServer"].ConnectionString)) using (SqlCommand sqlCmd = new SqlCommand(sql, sqlConn)) { sqlConn.Open(); int count = sqlCmd.ExecuteNonQuery(); sqlConn.Close(); return count == 1; } } catch (Exception ex) { return false; } } The problem is the password value, does anyone know how the password it is hashed?

  Read the article

• Need to speed up the results of this SQL statement. Any advice?

  - by jeffself

  I've got the following SQL Statement that needs some major speed up. The problem is I need to search on two fields, where each of them is calling several sub-selects. Is there a way to join the two fields together so I call the sub-selects only once? SELECT billyr, billno, propacct, vinid, taxpaid, duedate, datepif, propdesc FROM trcdba.billspaid WHERE date(datepif) > '01/06/2009' AND date(datepif) <= '01/06/2010' AND custno in (select custno from cwdba.txpytaxid where taxpayerno in (select taxpayerno from cwdba.txpyaccts where accountno in (select accountno from rtadba.reasacct where controlno = 1234567))) OR custno2 in (select custno from cwdba.txpytaxid where taxpayerno in (select taxpayerno from cwdba.txpyaccts where accountno in (select accountno from rtadba.reasacct where controlno = 1234567)))

  Read the article

• Designing a peer to peer network

  - by Varun

  I am designing a simple peer to peer network. The basic architecture will be as follows: A central server- that keeps track of all the peers. The job of this server is to keep track of all the peers that join the network. Every peer could do things: a. Download a file from it's peer b. Push a file (send a file) to it's peer. Could anybody please tell me what would be the best design for such a system? What would be the problems that i might run into and so on. I am planning to use Java as the programming language to implement. Would it be a good choice? Also, is it necessary that i would need a Linux box to develop the system? or is it fine if i use a Windows machine? Your help will be much appreciated! Thanks!

  Read the article

• Alternative to NOT EXISTS

  - by Dave Colwell

  Hi all, I have two tables linked by an ID column, lets call them Table A and table B. My goal is to find all the records in table A that have no record in table B. For instance: Table A: ID----Value 1-----value1 2-----value2 3-----value3 4-----value4 Table B ID----Value 1-----x 2-----y 4-----z 4-----l As you can see, record with ID = 3 does not exist in table B, so i want a query that will give me record 3 from table A. the way i am currently doing this is by saying AND NOT EXISTS (SELECT ID FROM TableB) but since the tables are huge, the performance on this is terrible. Also, when i tried using a Left Join where TableB.ID is null, it didnt work. Can anyone suggest an alternative?

  Read the article

• Casting to specific class in HQL

  - by bungrudi

  My situation is like this.. (note: for those who work with JBPM might already familiar with following data structures and HB mapping) Class LongInstance extends from VariableInstance, with the mapping for field "value" overridden in LongInstance. The mapping for VariableInstance is here and for LongInstance here. VariableInstance is polymorphically mapped to a collection in TokenVariableMap, the mapping is here. The question: how can I query the polymorphic collection using specific/overridden property of the member class? I'm looking for something like this "... from TokenVariableMaps tvm left join fetch tvm.variableInstances tvi where cast(tvi as LongInstance).value in(:vars)"

  Read the article

• Storage drives is causting system crash

  - by Chad

  I'm running Centos 5.4 with 750GB(ntfs) and 2TB drives for storage. Originally I installed the 750, everything seemed fine and then I installed the 2TB drive with NTFS already partitioned. I noticed when I would copy a lot of videos it would crash (no mouse or response from server) about 20min into it. After doing some troubleshooting I noticed the 750 would also crash when doing the same task so I decided that NTFS may be the problem. I unmounted the 2TB drive and tried to partition and format it using ext2 but when using parted it would crash at this point "writing inode tables". Looking at the dmesg logs I believe this is the error "mtrr: type mismatch for e0000000,10000000 old: write-back new: write-combining". Any idea as to what could be causing this?

  Read the article

• socket.error: [Errno 10054]

  - by C0d3r

  import socket, sys if len(sys.argv) !=3 : print "Usage: ./supabot.py <host> <port>" sys.exit(1) irc = sys.argv[1] port = int(sys.argv[2]) sck = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sck.connect((irc, port)) sck.send('NICK supaBOT\r\n') sck.send('USER supaBOT supaBOT supaBOT :supaBOT Script\r\n') sck.send('JOIN #darkunderground' + '\r\n') data = '' while True: data = sck.recv(1024) if data.find('PING') != -1: sck.send('PONG ' + data.split() [1] + '\r\n') print data elif data.find('!info') != -1: sck.send('PRIVMSG #darkunderground supaBOT v1.0 by sourD' + '\r\n') print sck.recv(1024) when I run this code I get this error.. socket.error: [Errno 10054] An existing connection was forcibly closed by the remote host it says that the error is in line 16, in data = sck.recv(1024)

  Read the article

• Writing a query to find MAX number in PL/SQL

  - by user2461116

  I am suppose to Write a query that will display the largest number of movies rented by one member and that member's name. Give the output column a meaningful name such as MAXIMUM NUMBER. This is what I have. select max(maximum_movies) from (select count(*)maximum_movies from mm_member join mm_rental on mm_rental.member_id = mm_member.member_id group by first, last); I got the maximum number but the output should be like this. First Last Maximum_movies John Doe 4 But the output is Maximum_movies 4 Any suggestions?

  Read the article

• Resource placement (optimal strategy)

  - by blackened

  I know that this is not exactly the right place to ask this question, but maybe a wise guy comes across and has the solution. I'm trying to write a computer game and I need an algorithm to solve this question: The game is played between 2 players. Each side has 1.000 dollars. There are three "boxes" and each player writes down the amount of money he is going to place into those boxes. Then these amounts are compared. Whoever placed more money in a box scores 1 point (if draw half point each). Whoever scores more points wins his opponents 1.000 dollars. Example game: Player A: [500, 500, 0] Player B: [333, 333, 334] Player A wins because he won Box A and Box B (but lost Box C). Question: What is the optimal strategy to place the money? I have more questions to ask (algorithm related, not math related) but I need to know the answer to this one first. Update (1): After some more research I've learned that these type of problems/games are called Colonel Blotto Games. I did my best and found few (highly technical) documents on the subject. Cutting it short, the problem I have (as described above) is called simple Blotto Game (only three battlefields with symmetric resources). The difficult ones are the ones with, say, 10+ battle fields with non-symmetric resources. All the documents I've read say that the simple Blotto game is easy to solve. The thing is, none of them actually say what that "easy" solution is.

  Read the article

• SQL Server uncorrelated subquery very slow

  - by brianberns

  I have a simple, uncorrelated subquery that performs very poorly on SQL Server. I'm not very experienced at reading execution plans, but it looks like the inner query is being executed once for every row in the outer query, even though the results are the same each time. What can I do to tell SQL Server to execute the inner query only once? The query looks like this: select * from Record record0_ where record0_.RecordTypeFK='c2a0ffa5-d23b-11db-9ea3-000e7f30d6a2' and ( record0_.EntityFK in ( select record1_.EntityFK from Record record1_ join RecordTextValue textvalues2_ on record1_.PK=textvalues2_.RecordFK and textvalues2_.FieldFK = '0d323c22-0ec2-11e0-a148-0018f3dde540' and (textvalues2_.Value like 'O%' escape '~') ) )

  Read the article

• Whats the most common waste of computing power in javascipt

  - by qwertymk

  We've all seen people who do this jQuery('a').each(function(){ jQuery(this)[0].innerHTML += ' proccessed'; }); function letsPoluteNS() { polute = ''; for (morePolution = 0; morePolution < arguments.length; morePolution++) polute.join(arguments[morePolution]); return polute; } and so on. I was wondering what people have seen the most common javascript/jQuery technique that is slowing down the page and/or wasting time for the javascript engine. PS I know that this question may not seem to fit into whats an accepted question, yet I'm asking for what the most common accepted waste is

  Read the article

• Including associations optimization in Rails

  - by Vitaly

  Hey, I'm looking for help with Ruby optimization regarding loading of associations on demand. This is simplified example. I have 3 models: Post, Comment, User. References are: Post has many comments and Comment has reference to User (:author). Now when I go to the post page, I expect to see post body + all comments (and their respective authors names). This requires following 2 queries: select * from Post -- to get post data (1 row) select * from Comment inner join User -- to get comment + usernames (N rows) In the code I have: Post.find(params[:id], :include => { :comments => [:author] } But it doesn't work as expected: as I see in the back end, there're still N+1 hits (some of them are cached though). How can I optimize that?

  Read the article

• Rails 4.2: "Assets should not be requested directly without their digests"

  - by Nowaker

  On Rails 4.2.0.beta1 I get an error: Assets should not be requested directly without their digests: Use the helpers in ActionView::Helpers to request fonts/source-sans-pro.woff The stylesheet: @font-face { font-family: 'Source Sans Pro'; font-style: normal; font-weight: 400; src: local('Source Sans Pro'), local('SourceSansPro-Regular'), url(/assets/source-sans-pro.woff) format('woff'); } The configuration is: config.serve_static_assets = true config.assets.js_compressor = :uglifier config.assets.compile = true config.assets.digest = true config.assets.version = '1.0' config.assets.paths << Rails.root.join('app', 'assets', 'fonts') config.assets.precompile += %w(.svg .eot .woff .ttf) Sure I can disable digests and it works again, but I'm interested in using them. Therefore, how do I make use of digests when I need to request source-sans-pro.woff? Please note that I place the fonts in assets/fonts directory, not the public/ directory. I don't see a difference between images and fonts, so I want to keep them under the same directory - app/assets.

  Read the article

• CakePHP: Using two tables for a single model

  - by mwaterous

  I'm just picking up development in CakePHP right now so forgive me if this seems obvious; it did to me when I first read about has, belongsTo, hasMany, etc. The problem is I would like to associate two tables with a single model, and was wondering if there was a way to configure this so that when CakePHP did it's queries it automatically performed a join on the two tables. I don't want to create a separate model for the second table as it is merely a meta information table - the master table will contain the primary information required, the meta table will be populated with secondary information that is not required and therefore may or may not be set for every row of the master table.

  Read the article

• What are good resources for computer graphics basics?

  - by Hanno Fietz

  During Flex programming, I recently ran into several questions (about box models, ways to join lines and misaligning pixels [on doctype]) regarding computer graphics and layout, where I felt that I lacked some basic background on things like concepts like the box model approaches mapping real numbers to a pixel raster (like font anti-aliasing) conventions found across drawing engines, like do you count y coordinates from top or bottom, and why I feel that reading some basic Wikipedia articles, books or tutorials on these subjects might help in phrasing my questions more specifically and debugging my code more systematically. I have repeatedly found myself writing tiny test apps in Flex, just to find out how the APIs do very basic stuff. My assumption would be that if I knew the right vocabulary and some general concepts, I could solve these questions much faster.

  Read the article

• Performance of a get unique elements/group by operation on an IEnumerable<T>.

  - by tolism7

  I was wondering how could I improve the performance of the following code: public class MyObject { public int Year { get; set; } } //In my case I have 30000 IEnumerable<MyObject> data = MethodThatReturnsManyMyObjects(); var groupedByYear = data.GroupBy(x => x.Year); //Here is the where it takes around 5 seconds foreach (var group in groupedByYear) //do something here. The idea is to get a set of objects with unique year values. In my scenario there are only 6 years included in the 30000 items in the list so the foreach loop will be executed 6 times only. So we have many items needing to be grouped in a few groups. Using the .Distinct() with an explicit IEqualityComparer would be an alternative but somehow I feel that it wont make any difference. I can understand if 30000 items is too much and that i should be happy with the 5 seconds I get, but I was wondering if the above can be imporved performance wise. Thanks.

  Read the article

• Partioning the Table into .net - Creating columner database.

  - by Omky

  Hello Geeks, I am developing some tool for BI. There are terms like Fact, Dimensions and Measures. My application will connect to the normal database and read the data from that table. Now, I want to convert all this data into columnar database. That is all the columns from this table will be transfer into 3 tables each. Consider below table:- ID Product 1 XYZ 2 ABC 3 ABC Now, I want to convert the Product column i.e. dimension into 3 tables. dim_product_table:- ID Product 1 XYZ 2 ABC dim_product_fmk(fact map by key):- Where we will store key-value pair of Key Row 1 1 1 2 2 3 dim_product_fmr(fact map by row):- The above table will be reversed. Row Key 1 1 2 1 3 2 The another requirement is all above table should be generated dynamically and I should be able to JOIN all those. Can anybody help me? Thanks in advance.

  Read the article

• Is Amazon SQS the right choice here? Rails performance issue.

  - by ole_berlin

  I'm close to releasing a rails app with the common networking features (messaging, wall, etc.). I want to use some kind of background processing (most likely Bj) for off-loading tasks from the request/response cycle. This would happen when users invite friends via email to join and for email notifications. I'm not sure if I should just drop these invites and notifications in my Database, using a model and then just process it with a worker process every x minutes or if I should go for Amazon SQS, storing the messages and invites there and let my worker retrieve it from Amazon SQS for processing (sending the invites / notifications). The Amazon approach would get load off my Database but I guess it is slower to retrieve messages from there. What do you think?

  Read the article

• concatenate multi values in one record without duplication

  - by mikehjun

  I have a dbf table like below which is the result of one to many join from two tables. I want to have unique zone values from one Taxlot id field. table name: input table tid ----- zone 1 ------ A 1 ------ A 1 ------ B 1 ------ C 2 ------ D 2 ------ E 3 ------ C Desirable output table table name: input table tid ----- zone 1 ------ A, B, C 2 ------ D, E 3 ------ C I got some help but couldn't make it to work. inputTbl = r"C:\temp\input.dbf" taxIdZoningDict = {} searchRows = gp.searchcursor(inputTbl) searchRow = searchRows.next() while searchRow: if searchRow.TID in taxIdZoningDict: taxIdZoningDict[searchRow.TID].add(searchRow.ZONE) else: taxIdZoningDict[searchRow.TID] = set() #a set prevents dulpicates! taxIdZoningDict[searchRow.TID].add(searchRow.ZONE) searchRow = searchRows.next() outputTbl = r"C:\temp\output.dbf" gp.CreateTable_management(r"C:\temp", "output.dbf") gp.AddField_management(outputTbl, "TID", "LONG") gp.AddField_management(outputTbl, "ZONES", "TEXT", "", "", "20") tidList = taxIdZoningDict.keys() tidList.sort() #sorts in ascending order insertRows = gp.insertcursor(outputTbl) for tid in tidList: concatString = "" for zone in taxIdZoningDict[tid] concatString = concatString + zone + "," insertRow = insertRows.newrow() insertRow.TID = tid insertRow.ZONES = concatString[:-1] insertRows.insertrow(insertRow) del insertRow del insertRows

  Read the article

• Dynamic order by without using dynamic sql ?

  - by Rohit

  I have the following stored procedure which can be sorted ascending and descending on TemplateName,CreatedOn and UploadedBy. The following SP when runs doesnot sort records.if i replace 2,3,4 by columnname, i got an error message "Conversion failed when converting the nvarchar value 'Test Template' to data type int.".Please suggest how to achieve sorting. CREATE PROCEDURE [dbo].[usp_SEL_GetRenderingTemplate] ( @facilityID INT, @sortOrder VARCHAR(5), @sortExpression VARCHAR(100), @errorCode INT OUTPUT ) AS BEGIN SET NOCOUNT ON ; BEGIN TRY SET @sortOrder = CASE @sortOrder WHEN 'Ascending' THEN 'ASC' WHEN 'Descending' THEN 'DESC' ELSE 'ASC' END SELECT TemplateID, TemplateName, CreatedOn, ( [user].LastName + ' ' + [user].FirstName ) AS UploadedBy FROM Templates INNER JOIN [user] ON [user].UserID = Templates.CreatedBy WHERE facilityid = @facilityID ORDER BY CASE WHEN @sortExpression = 'TemplateName' AND @sortOrder = 'ASC' THEN 2 WHEN @sortExpression = 'CreatedOn' AND @sortOrder = 'ASC' THEN 3 WHEN @sortExpression = 'UploadedBy' AND @sortOrder = 'ASC' THEN 4 END ASC, CASE WHEN @sortExpression = 'TemplateName' AND @sortOrder = 'DESC' THEN 2 WHEN @sortExpression = 'CreatedOn' AND @sortOrder = 'DESC' THEN 3 WHEN @sortExpression = 'UploadedBy' AND @sortOrder = 'DESC' THEN 4 END DESC SET @errorCode = 0 END TRY BEGIN CATCH SET @errorCode = -1 DECLARE @errorMsg AS VARCHAR(MAX) DECLARE @utcDate AS DATETIME SET @errorMsg = CAST(ERROR_MESSAGE() AS VARCHAR(MAX)) SET @utcDate = CAST(GETUTCDATE() AS DATETIME) EXEC usp_INS_LogException 'usp_SEL_GetFacilityWorkTypeList', @errorMsg, @utcDate END CATCH END

  Read the article

• Get the count of A -> B and B->A without duplicates

  - by TomGasson

  I have a table like so: index|from | to ------------------ 1 | ABC | DEF 2 | ABC | GHI 3 | ABC | GHI 4 | ABC | JKL 5 | ABC | JKL 6 | ABC | JKL 7 | DEF | ABC 8 | DEF | GHI 9 | DEF | JKL 10 | GHI | ABC 11 | GHI | ABC 12 | GHI | ABC 13 | JKL | DEF And I need to count how the total times between the points (regardless of direction) to get the result: A | B | count ----------------- ABC | DEF | 2 ABC | GHI | 5 ABC | JKL | 3 DEF | GHI | 1 DEF | JKL | 2 So far I can get: SELECT `a`.`from` as `A`, `a`.`to` as `B`, (`a`.`count` + `b`.`count`) as `count` FROM (SELECT `from`, `to`, count(*) as `count` FROM `table` GROUP BY 1,2) `a` LEFT OUTER JOIN (SELECT `from`,`to`, count(*) as `count` FROM `table` GROUP BY 1,2) `b` ON `a`.`from` = `b`.`to` AND `a`.`to` = `b`.`from` But I'm unsure how to remove the A/B swapped duplicates.

  Read the article

• How to Split a Cell Part of a Row and Keep the Rest of the Rows - Google Spreadsheets

  - by user3527095

  I am trying to do the following: I have row 1. I have values A1, B1, and C1. A1 contains a few names separated by a comma. I want to split A1 by these names while copying over the values from B1 and C1 into the split columns of A1. For example, I have this: (A1 B1 C1) bob,sam,bill 99 10 I want to have this: bob 99 10 sam 99 10 bill 99 10 I am also doing this on Google Sheets, I tried using combinations of Split, Join, and Transpose but can't seem to figure it out. Any help would be appreciated, thanks. EDIT: any updates? EDIT: still trying to figure this out.

  Read the article

< Previous Page | 362 363 364 365 366 367 368 369 370 371 372 373  | Next Page >