Search Results

Search found 20224 results on 809 pages for 'query optimization'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 183/809 | < Previous Page | 179 180 181 182 183 184 185 186 187 188 189 190  | Next Page >

  • Common causes of slow performing jQuery and how to optimize the code?

    - by Polaris878
    Hello, This might be a bit of a vague or general question, but I figure it might be able to serve as a good resource for other jQuery-ers. I'm interested in common causes of slow running jQuery and how to optimize these cases. We have a good amount of jQuery/JavaScript performing actions on our page... and performance can really suffer with a large number off elements. What are some obvious performance pitfalls you know of with jQuery? What are some general optimizations a jQuery-er can do to squeeze every last bit of performance out of his/her scripts? One example: a developer may use a selector to access an element that is slower than some other way. Thanks

    Read the article

  • Controlling read and write access width to memory mapped registers in C

    - by srking
    I'm using and x86 based core to manipulate a 32-bit memory mapped register. My hardware behaves correctly only if the CPU generates 32-bit wide reads and writes to this register. The register is aligned on a 32-bit address and is not addressable at byte granularity. What can I do to guarantee that my C (or C99) compiler will only generate full 32-bit wide reads and writes in all cases? For example, if I do a read-modify-write operation like this: volatile uint32_t* p_reg = 0xCAFE0000; *p_reg |= 0x01; I don't want the compiler to get smart about the fact that only the bottom byte changes and generate 8-bit wide read/writes. Since the machine code is often more dense for 8-bit operations on x86, I'm afraid of unwanted optimizations. Disabling optimizations in general is not an option.

    Read the article

  • How can I optimize this loop?

    - by Moshe
    I've got a piece of code that returns a super-long string that represents "search results". Each result is represented by a double HTML break symbol. For example: Result1<br><br>Result 2<br><br>Result3 I've got the following loop that takes each result and puts it into an array, stripping out the break indicator, "kBreakIndicator" (<br><br>). The problem is that this lopp takes way too long to execute. With a few results it's fine, but once you hit a hundred results, it's about 20-30 seconds slower. It's unacceptable performance. What can I do to improve performance? Here's my code: content is the original NSString. NSMutableArray *results = [[NSMutableArray alloc] init]; //Loop through the string of results and take each result and put it into an array while(![content isEqualToString:@""]){ NSRange rangeOfResult = [content rangeOfString:kBreakIndicator]; NSString *temp = (rangeOfResult.location != NSNotFound) ? [content substringToIndex:rangeOfResult.location] : nil; if (temp) { [results addObject:temp]; content = [[[content stringByReplacingOccurrencesOfString:[NSString stringWithFormat:@"%@%@", temp, kBreakIndicator] withString:@""] mutableCopy] autorelease]; }else{ [results addObject:[content description]]; content = [[@"" mutableCopy] autorelease]; } } //Do something with the results array. [results release];

    Read the article

  • how can i substitute a NULL value for a 0 in an SQL Query result

    - by Name.IsNullOrEmpty
    SELECT EmployeeMaster.EmpNo, Sum(LeaveApplications.LeaveDaysTaken) AS LeaveDays FROM EmployeeMaster FULL OUTER JOIN LeaveApplications ON EmployeeMaster.id = LeaveApplications.EmployeeRecordID INNER JOIN LeaveMaster ON EmployeeMaster.id = LeaveMaster.EmpRecordID GRoup BY EmployeeMaster.EmpNo order by LeaveDays Desc with the above query, if an employee has no leave application record in table LeaveApplications, then their Sum(LeaveApplications.LeaveDaysTaken) AS LeaveDays column returns NULL. What i would like to do is place a value of 0 (Zero) instead of NULL. I want to do this because i have a calculated column in the same query whose formular depends on the LeaveDays returned and when LeaveDays is NULL, the formular some how fails. Is there away i can put 0 for NULL such that that i can get my desired result.

    Read the article

  • Composite primary keys in N-M relation or not?

    - by BerggreenDK
    Lets say we have 3 tables (actually I have 2 at the moment, but this example might illustrate the thought better): [Person] ID: int, primary key Name: nvarchar(xx) [Group] ID: int, primary key Name: nvarchar(xx) [Role] ID: int, primary key Name: nvarchar(xx) [PersonGroupRole] Person_ID: int, PRIMARY COMPOSITE OR NOT? Group_ID: int, PRIMARY COMPOSITE OR NOT? Role_ID: int, PRIMARY COMPOSITE OR NOT? Should any of the 3 ID's in the relation PersonGroupRole be marked as PRIMARY key or should they all 3 be combined into one composite?? whats the real benefit of doing it or not? I can join anyways as far as I know, so Person JOIN PersonGroupRole JOIN Group gives me which persons are in which Groups etc. I will be using LINQ/C#/.NET on top of SQL-express and SQL-server, so if there is any reasons regarding language/SQL that might make the choice more clear, thats the platform I ask about. Looking forward to see what answers pops up, as I have thought of these primary keys/indexes many times when making combined ones.

    Read the article

  • Query to update rowNum

    - by BrokeMyLegBiking
    Can anyone help me write this query more efficiently? I have a table that captures TCP traffic, and I'd like to update a column called RowNumForFlow which is simly the sequential number of the IP packet in that flow. The code below works fine, but it is slow. declare @FlowID int declare @LastRowNumInFlow int declare @counter1 int set @counter1 = 0 while (@counter1 < 1) BEGIN set @counter1 = @counter1 + 1 -- 1) select top 1 @FlowID = t.FlowID from Traffic t where t.RowNumInFlow is null if (@FlowID is null) break -- 2) set @LastRowNumInFlow = null select top 1 @LastRowNumInFlow = RowNumInFlow from Traffic where FlowID=@FlowID and RowNumInFlow is not null order by ID desc if @LastRowNumInFlow is null set @LastRowNumInFlow = 1 else set @LastRowNumInFlow = @LastRowNumInFlow + 1 update Traffic set RowNumInFlow = @LastRowNumInFlow where ID = (select top 1 ID from Traffic where flowid = @FlowID and RowNumInFlow is null) END Example table values after query has run: ID FlowID RowNumInFlow 448923 44 1 448924 44 2 448988 44 3 448989 44 4 448990 44 5 448991 44 6 448992 44 7 448993 44 8 448995 44 9 448996 44 10 449065 44 11 449063 45 1 449170 45 2 449171 45 3 449172 45 4 449187 45 5

    Read the article

  • optimize a string.Format + replace.

    - by acidzombie24
    I have this function. The visual studio profile marked the line with string.Format as hot and were i spend much of my time. How can i write this loop more efficiently? public string EscapeNoPredicate(string sz) { var s = new StringBuilder(sz); s.Replace(sepStr, sepStr + sepStr); foreach (char v in IllegalChars) { string s2 = string.Format("{0}{1:X2}", seperator, (Int16)v); s.Replace(v.ToString(), s2); } return s.ToString(); }

    Read the article

  • Why isn't the copy constructor elided here?

    - by Jesse Beder
    (I'm using gcc with -O2.) This seems like a straightforward opportunity to elide the copy constructor, since there are no side-effects to accessing the value of a field in a bar's copy of a foo; but the copy constructor is called, since I get the output meep meep!. #include <iostream> struct foo { foo(): a(5) { } foo(const foo& f): a(f.a) { std::cout << "meep meep!\n"; } int a; }; struct bar { foo F() const { return f; } foo f; }; int main() { bar b; int a = b.F().a; return 0; }

    Read the article

  • MS Access caching of reports / query results

    - by FrustratedWithFormsDesigner
    Is it possible to cache a query or report the first time it is run? It seems that opening a report will re-query the datasource. For certain queries, the data source does not change frequently enough that I'd be worried about a cache being out of date (users are notified when the database changes), and it would be much easier for the users to be able to open the report instantly rather than having to wait several minutes every time they want to see the data (though I realize if they close the file the caches will be lost - that's OK). Data comes from an ODBC connection to Oracle, using Access 2003.

    Read the article

  • Help in formulating sql query

    - by AJ
    Here is my scenario Table 1: GID || Info1 Table 2: GID || Tb1GID (refers to GID of Table1) || Info2 Table 3: GID || Info3 Table 4: GID || Tb2GID (refers to GID of Table2 || Tb3GID (refers to Table3 GID || Value Now I have to build an sql query to get the value, given a particular Info1, Info2, Info3. Essentially, I have to get the GID, of table 1 using info1, GID of table to , by mapping info2 and GID of table 1. And then get the GID of table 3 using info 3. And combine these to GIDs to get the value in table 4. What is the most optimal way of constructing an sql query for this one?

    Read the article

  • Can a conforming C# compiler optimize away a local (but unused) variable if it is the only strong re

    - by stakx
    The title says it all, but let me explain: void Case_1() { var weakRef = new WeakReference(new object()); GC.Collect(); // <-- doesn't have to be an explicit call; just assume that // garbage collection would occur at this point. if (weakRef.IsAlive) ... } In this code example, I obviously have to plan for the possibility that the new'ed object is reclaimed by the garbage collector; therefore the if statement. (Note that I'm using weakRef for the sole purpose of checking if the new'ed object is still around.) void Case_2() { var unusedLocalVar = new object(); var weakRef = new WeakReference(unusedLocalVar); GC.Collect(); // <-- doesn't have to be an explicit call; just assume that // garbage collection would occur at this point. Debug.Assert(weakReferenceToUseless.IsAlive); } The main change in this code example from the previous one is that the new'ed object is strongly referenced by a local variable (unusedLocalVar). However, this variable is never used again after the weak reference (weakRef) has been created. Question: Is a conforming C# compiler allowed to optimize the first two lines of Case_2 into those of Case_1 if it sees that unusedLocalVar is only used in one place, namely as an argument to the WeakReference constructor? i.e. is there any possibility that the assertion in Case_2 could ever fail?

    Read the article

  • How can I speed up line by line reading of an ASCII file? (C++)

    - by Jon
    Here's a bit of code that is a considerable bottleneck after doing some measuring: //----------------------------------------------------------------------------- // Construct dictionary hash set from dictionary file //----------------------------------------------------------------------------- void constructDictionary(unordered_set<string> &dict) { ifstream wordListFile; wordListFile.open("dictionary.txt"); string word; while( wordListFile >> word ) { if( !word.empty() ) { dict.insert(word); } } wordListFile.close(); } I'm reading in ~200,000 words and this takes about 240 ms on my machine. Is the use of ifstream here efficient? Can I do better? I'm reading about mmap() implementations but I'm not understanding them 100%. The input file is simply text strings with *nix line terminations.

    Read the article

  • How can I store large amount of data from a database to XML (speed problem, part three)?

    - by Andrija
    After getting some responses, the current situation is that I'm using this tip: http://www.ibm.com/developerworks/xml/library/x-tipbigdoc5.html (Listing 1. Turning ResultSets into XML), and XMLWriter for Java from http://www.megginson.com/downloads/ . Basically, it reads date from the database and writes them to a file as characters, using column names to create opening and closing tags. While doing so, I need to make two changes to the input stream, namely to the dates and numbers. // Iterate over the set while (rs.next()) { w.startElement("row"); for (int i = 0; i < count; i++) { Object ob = rs.getObject(i + 1); if (rs.wasNull()) { ob = null; } String colName = meta.getColumnLabel(i + 1); if (ob != null ) { if (ob instanceof Timestamp) { w.dataElement(colName, Util.formatDate((Timestamp)ob, dateFormat)); } else if (ob instanceof BigDecimal){ w.dataElement(colName, Util.transformToHTML(new Integer(((BigDecimal)ob).intValue()))); } else { w.dataElement(colName, ob.toString()); } } else { w.emptyElement(colName); } } w.endElement("row"); } The SQL that gets the results has the to_number command (e.g. to_number(sif.ID) ID ) and the to_date command (e.g. TO_DATE (sif.datum_do, 'DD.MM.RRRR') datum_do). The problems are that the returning date is a timestamp, meaning I don't get 14.02.2010 but rather 14.02.2010 00:00:000 so I have to format it to the dd.mm.yyyy format. The second problem are the numbers; for some reason, they are in database as varchar2 and can have leading zeroes that need to be stripped; I'm guessing I could do that in my SQL with the trim function so the Util.transformToHTML is unnecessary (for clarification, here's the method): public static String transformToHTML(Integer number) { String result = ""; try { result = number.toString(); } catch (Exception e) {} return result; } What I'd like to know is a) Can I get the date in the format I want and skip additional processing thus shortening the processing time? b) Is there a better way to do this? We're talking about XML files that are in the 50 MB - 250 MB filesize category.

    Read the article

  • Tree iterator, can you optimize this any further?

    - by Ron
    As a follow up to my original question about a small piece of this code I decided to ask a follow up to see if you can do better then what we came up with so far. The code below iterates over a binary tree (left/right = child/next ). I do believe there is room for one less conditional in here (the down boolean). The fastest answer wins! The cnt statement can be multiple statements so lets make sure this appears only once The child() and next() member functions are about 30x as slow as the hasChild() and hasNext() operations. Keep it iterative <-- dropped this requirement as the recursive solution presented was faster. This is C++ code visit order of the nodes must stay as they are in the example below. ( hit parents first then the children then the 'next' nodes). BaseNodePtr is a boost::shared_ptr as thus assignments are slow, avoid any temporary BaseNodePtr variables. Currently this code takes 5897ms to visit 62200000 nodes in a test tree, calling this function 200,000 times. void processTree (BaseNodePtr current, unsigned int & cnt ) { bool down = true; while ( true ) { if ( down ) { while (true) { cnt++; // this can/will be multiple statesments if (!current->hasChild()) break; current = current->child(); } } if ( current->hasNext() ) { down = true; current = current->next(); } else { down = false; current = current->parent(); if (!current) return; // done. } } }

    Read the article

  • SQL server 2005 query not running

    - by Aayushi
    Hi, Before posting this question, I have tried so many things but that was not helpful for me. I want to rename the column of table at sql server 2005, following query I have run at sql server2005: 1) ALTER TABLE Details RENAME COLUMN AccountID TO UID; but it gives me the error: Incorrect syntax near the keyword 'COLUMN'. 2)I have added one new column in the table by query: ALTER TABLE Details ADD BID uniqueidentifier; and then I want to set the coulmn property to not null . How can i do that? Thanks in advance AS

    Read the article

  • Counting context switches per thread

    - by Sarmun
    Is there a way to see how many context switches each thread generates? (both in and out if possible) Either in X/s, or to let it run and give aggregated data after some time. (either on linux or on windows) I have found only tools that give aggregated context-switching number for whole os or per process. My program makes many context switches (50k/s), probably a lot not necessary, but I am not sure where to start optimizing, where do most of those happen.

    Read the article

  • Scalably processing large amount of comlpicated database data in PHP, many times a day.

    - by Eph
    I'm soon to be working on a project that poses a problem for me. It's going to require, at regular intervals throughout the day, processing tens of thousands of records, potentially over a million. Processing is going to involve several (potentially complicated) formulas and the generation of several random factors, writing some new data to a separate table, and updating the original records with some results. This needs to occur for all records, ideally, every three hours. Each new user to the site will be adding between 50 and 500 records that need to be processed in such a fashion, so the number will not be steady. The code hasn't been written, yet, as I'm still in the design process, mostly because of this issue. I know I'm going to need to use cron jobs, but I'm concerned that processing records of this size may cause the site to freeze up, perform slowly, or just piss off my hosting company every three hours. I'd like to know if anyone has any experience or tips on similar subjects? I've never worked at this magnitude before, and for all I know, this will be trivial to the server and not pose much of an issue. As long as ALL records are processed before the next three hour period occurs, I don't care if they aren't processed simultaneously (though, ideally, all records belonging to a specific user should be processed in the same batch), so I've been wondering if I should process in batches every 5 minutes, 15 minutes, hour, whatever works, and how best to approach this (and make it scalable in a way that is fair to all users)?

    Read the article

  • Specific template for the first element.

    - by Kalinin
    I have a template: <xsl:template match="paragraph"> ... </xsl:template> I call it: <xsl:apply-templates select="paragraph"/> For the first element I need to do: <xsl:template match="paragraph[1]"> ... <xsl:apply-templates select="."/><!-- I understand that this does not work --> ... </xsl:template> How to call <xsl:apply-templates select="paragraph"/> (for the first element paragraph) from the template <xsl:template match="paragraph[1]">? So far that I have something like a loop. I solve this problem so (but I do not like it): <xsl:for-each select="paragraph"> <xsl:choose> <xsl:when test="position() = 1"> ... <xsl:apply-templates select="."/> ... </xsl:when> <xsl:otherwise> <xsl:apply-templates select="."/> </xsl:otherwise> </xsl:choose> </xsl:for-each>

    Read the article

  • Compile Flex application without debug? Optimisation options for flex compiler?

    - by maoanz
    I have created a simple test application with the following code var i : int; for (i=0; i<3000000; i++){ trace(i); } When I run the application, it's very slow to load, which means the "trace" is running. I check the flash player by right-clicking, the debugger option is not enable. So I wonder if there is an option to put in compiler to exclude the trace. Otherwise, I have to remove manually all the trace in the program. Are there any other options of compiler to optimize the flex application in a maximum way? Thanks

    Read the article

  • Passing values for multi-value parameter in SSRS query string

    - by Andy Xufuris
    I have two reports built using SSRS 2005. The first report is set to navigate to the second when a specific field is clicked. There is a multi-value parameter on the second report. I need to pass multiple values for this parameter in the URL query string when calling this report. Is there a way to pass multiple values for a parameter in the query string of a report? Or can you pass a parameter that will cause the Select All value to be selected?

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 179 180 181 182 183 184 185 186 187 188 189 190  | Next Page >