oracle11g - Oracle: performance about filtering results from remote view -

-

I have a remote database that has a view v_myview. I am working on a local database, Usage is done to access v_myview on the database A. If I ask it like this: 

  choose * v_myview to @ dblink;   
 This gives half a million lines, I just want to get some specific rows from the view, e.g., to get the lines with id = 123, my query  
  select v_myview @ dblink where id = 123;   
 This question comes to me when I run this query, then the remote database will generate the first half-million lines, before id = 123 To find the rows together? Or remote visualization is applied to your filter first, then the first question to DB is to retrieve half a million lines without first? How do I know that. Thanks!   
 
 
 Oracle is free to do either. You will need to see the query plan to see if filtering is done locally or remotely.  
 Probably, in any case you are presenting, the adapter expects that it will be more to send the filter to the remote server rather than filtering only five lakh lines locally This calculation can be different if the optifier expects that the unfiltered query will need to return a line rather than half a million lines and it is different So if the query becomes more complicated to do and time to call the function to include the local table or a local server.

Comments

Post a Comment

Popular posts from this blog

excel vba - How to delete Solver(SOLVER.XLAM) code -

-
After opening several examples of macro / code written, I suddenly get stuck with a code that seems safe. Solver (SOLVER.XLAM) is doing this notation and I would like to remove it from my system. I do not think this is a relativant code. Can anyone tell me what should I do? I have already installed something to remove the password but Solver is still asking for password and I can not get rid of it! itemprop = "text"> Solver Excel is add-in If you want to delete it, then Excel Application & gt; Options & gt; Add-ins & gt; Search for 'Go to' button and gt; Uncheck the solver on the list like press something (I can not give you the exact path because I have the Polish version of Excel). Trying to open Solver's VBA code is not good because it There is allegedly copyright. Besides, I do not think Solver creates any disadvantages while working with Excel or VBA.
Read more

github - Teamcity & Git - PR merge builds - anyway to get HEAD commit hash? -

-
I have a team city build project with Gitbab VCS route, I have been triggered for both / head on PR and / Merge the referee. The annoying thing is that you can not do anything useful with the merged hash - it is not present in Gitobb. I want to exclude newsgate packages with head in gutub comet situations in the version number along with Hewash (Newsaging 7) for the music build, but against head hash. However, I can not see a way to get the head hashes while constructing that merge. I just want to head because it's useless - we only care about merge. (PR - Pull Request) This command works reliably while running One on / merge is git log --no-merge -1 ---- = '% h'
Read more

ios - Replace text in UITextView run slowly -

-
I have a UITextView and I change a word like the code at the end of UITextView.text: - (void) Replace TexttechWitWord: (NSString *) word {NSString * currentTextViewText = self.textView.text; CurrentTextViewText = [currentTextViewText stringByReplacingCharactersInRange: NSMakeRange ([self.textView.text length] - [word length], [word length]) withString: word; Self.textView.text = currentTextViewText; } Replacement work is fine, but it runs very slowly and very slowly when the textView now lengthens Is there any better way? I try the replacement range: with text for a week but still stuck. Not to know how to use it to replace it in your case. Please guide! Thanks in advance! This is an important job. As you are using an irreversible string and you are creating a very long string and before Assigned to NSString created from. NSString will be used instead of NSMutableString . - (UITableViewCell *) TableView: (UITableView *) Table View CellForOutPath: (NSIndex...
Read more