batch-processing

问题 When building a web application, it is a standard practice to use one Unit of Work per HTTP request, and flush all the changes and commit the transaction once after handling the request. What approach is used when building a batch process? Is one Unit of Work instance used for the whole execution of the process, with transactions committed periodically at logical points? This may be more of a discussion than a factual question, but I'm hoping to find out if there is a commonly-accepted "best

问题 I have a function which basically returns the entire data from the table.How can i implement batch fetching so that the data will be returned in batches of 60,000 rows at a time. Will the following logic applicable in this scenario? http://javainnovations.blogspot.com/2008/07/batch-insertion-in-hibernate.html 回答1: In hibernate.properties , set the batch size using the parameter hibernate.jdbc.batch_size= 'your_value' 回答2: To select data in a batch, you can apply data pagination by setting the

问题 I found existing questions similar to this one that did not actually have a clear answer to the question. A normal batch preparedstatement with one sql query would look something like this: private static void batchInsertRecordsIntoTable() throws SQLException { Connection dbConnection = null; PreparedStatement preparedStatement = null; String insertTableSQL = "INSERT INTO DBUSER" + "(USER_ID, USERNAME, CREATED_BY, CREATED_DATE) VALUES" + "(?,?,?,?)"; try { dbConnection = getDBConnection();

问题 Use case: Read 10 million rows [10 columns] from database and write to a file (csv format). Which ItemReader implementation among JdbcCursorItemReader & JdbcPagingItemReader would be suggested? What would be the reason? Which would be better performing (fast) in the above use case? Would the selection be different in case of a single-process vs multi-process approach? In case of a multi-threaded approach using TaskExecutor, which one would be better & simple? 回答1: To process that kind of data

问题 I'm using NHibernate currently. I have a situation where I need to save a bunch of records to the database like this: var relatedTopics = GetRelatedTopics(topic); foreach (var relatedTopic in relatedTopics /* could be anywhere from 10 - 1000+ */) { var newRelatedTopic = new RelatedTopic { RelatedTopicUrl = relatedTopic, TopicUrl = topic.Name }; _repository.Save(newRelatedTopic); } When there are a ton of records to save this is obviously very taxing having to hit the database that many times.

问题 I need to copy a file x.dtsx from location a to location b. If x.dtsx already exists in b then I need to rename x.dtsx to x_Standby.dtsx Then, after renaming copy x.dtsx to b My current code looks like this: if exists %1 rename %1 %(should be 1_standy.extension) xcopy %1 %2 回答1: If you use the Command Processor Extensions (which is default on Windows 2000 and later) then you can use the following optional syntax: %~1 - expands %1 removing any surrounding quotes (") %~f1 - expands %1 to a

问题 I have a batch file that starts an app with a lot of command-line parameters: "C:\Program Files (x86)\Common Files\Microsoft Shared\DevServer\11.0\WebDev.WebServer40.exe" /port:1672 /path:"C:\Code.Net\My App\Iteration 6\REL_6.8.806_PerfEnhanceV\Fusion\Code\CC.Fusion\CC.Fusion.Services" /vpath:"/FusionServices" The problem is that when I run the batch file, the DOS window stays up until the command completes and I would like it to go away. So I tried using the start command, but placing it in

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 3 years ago . This has been asked before, but I don't really know if the answers help me. Here is my problem: I got a bunch of (10,000 or so) pdf files. Some were text files that were saved using adobe's print feature (so their text is perfect and I don't want to risk screwing them up). And some were scanned images (so they

问题 I am using the R package twitteR to post items to Twitter. I put everything inside of a function and it works fine. However, I would like to run the function without being prompted for a response, and I haven't figured out how to do that. Any suggestions? Here are the bare bones of my function: doit <- function(<snip>) { <snip> # connect to Twitter setup_twitter_oauth(api_key, api_secret, access_token, access_token_secret) <snip> } When I run the function from the command line, I am prompted

问题 Is there any way in Notepad++ (or even with another tool) to change the line ending automatically on multiple files in one go ? i.e. convert a mix of windows EOL ( CRLF ) and UNIX EOL ( LF ) files to be all Windows EOL ( CRLF ) 回答1: The Replace dialog can handle extended characters like EOL. Just change "Search Mode" to "Extended", and you can work with EOL (\r\n in Windows or \n in Unix), tabs (\t), etc. You can also use the Find in Files tab of the dialog to do the replace across multiple