indexed

In my application I am displaying contacts in table view with indexed list. I am displaying indexed list as follow: static NSString *letters = @"abcdefghijklmnopqrstuvwxyz#"; -(void)getAllUserInfoUsingBlock:(lclResultsArray) block { dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{ NSMutableArray *allUserInfoArray = [[NSMutableArray alloc]init]; NSLog(@"[letters length]:- %d",[letters length]); for (int i = 0; i < [letters length]; i++ ) { NSMutableDictionary *row = [[NSMutableDictionary alloc] init]; char currentLetter[2] = { toupper([letters characterAtIndex:i]),

I have a 1 TB, 600m row, table which has a misguided choice of indexed columns, specifically a clustered index on the primary key column which is never used in a select query. I want to remove the clustered index from this row and create it on a number of other rows. Table is currently like this: colA (PK, nvarchar(3)) [clustered index pt b] colB (PK, bigint) [clustered index pt a] colC (DateTime) [non-clustered index] colD (Money) [non-clustered index] colE (bit) [no index] colF (bit) [no index] colG (int) [no index] more non-indexed columns I would like to change it to look like this: colA

I have normalized tables in a database and to denormalize it, I created a view out of two tables. When I tried to create a clustered index on the view, it wouldn't let me, as the view was created with a left outer join. I used a left join because I want the null values to show up in the resulting view, much like how it was suggested in this earlier post. Question on join where one column one side is null The table structure and relationship is very much similar to what was described in the above link. I seemed to hit a wall here as I couldn't convert my left join into an inner join, as that

I'm trying to get a clear idea of when I should be using indexed arrays of OpenGL vertices, drawn with gl[Multi]DrawElements and the like, versus when I should simply use contiguous arrays of vertices, drawn with gl[Multi]DrawArrays. ( Update: The consensus in the replies I got is that one should always be using indexed vertices.) I have gone back and forth on this issue several times, so I'm going to outline my current understanding, in the hopes someone can either tell me I'm now finally more or less correct, or else point out where my remaining misunderstandings are. Specifically, I have

I want to construct some arrays that will remain in order to get fast searches. If I use something like this: let dictionary: [Int:Int] = [:] for i in 0 ..< 10000000 { dictionary[i] = 0 } Would the query: dictionary[n] == nil be performed in logarithmic time? If yes, is it the same for other types: Float, Double, String. And finally, I need it to work with the UUID type, will it work? Hamish Swift's Dictionary is implemented with a hash table , therefore lookups will typically be done in O(1) time, assuming a good hashing algorithm. As @rmaddy says , this therefore means that the type of key

i'm trying to edit the pixels of a 8bpp. Since this PixelFormat is indexed i'm aware that it uses a Color Table to map the pixel values. Even though I can edit the bitmap by converting it to 24bpp, 8bpp editing is much faster (13ms vs 3ms). But, changing each value when accessing the 8bpp bitmap results in some random rgb colors even though the PixelFormat remains 8bpp. I'm currently developing in c# and the algorithm is as follows: (C#) 1- Load original Bitmap at 8bpp 2- Create Empty temp Bitmap with 8bpp with the same size as the original 3-LockBits of both bitmaps and, using P/Invoke,