data-partitioning

MySQL Partitioning: Performance increase For multiple partitioned tables. Why?

由 情到浓时终转凉″ 提交于 2019-12-11 01:57:42
问题 I have implemented a benchmark which tests the permanence of reads and writes on 10 different tables. I have 10 java threads , each performs queries on its table only: Threads 1 performs operations on Table1, Threads 2 performs operations on Table2, I have compered the performance of running those threads in parallel executing multiple reads on non partitioned Table[1-10], vs the performance of the same benchmark while partitioning each TableX to 9 equal partitions (each represents a week of

How to partition an image to 64 block in matlab

由 狂风中的少年 提交于 2019-12-09 01:21:58
问题 I want to compute the Color Layout Descriptor (CLD) for each image.. this algorithm include four stages . in the First stage I must Partition each image into 64 block i(8×8)n order to compute a single representative color from each block .. I try to partition the image into 64 block by using (For loop) but I get 64 ting image. I want to get image with (8×8) block in order to complete the algorithm by apply the DCT transformation then Zigzag scanning 回答1: Here some pieces of code that I wrote

Partition a Set into k Disjoint Subset

由 爷，独闯天下 提交于 2019-12-08 09:21:28
问题 Give a Set S , partition the set into k disjoint subsets such that the difference of their sums is minimal. say, S = {1,2,3,4,5} and k = 2 , so { {3,4}, {1,2,5} } since their sums {7,8} have minimal difference. For S = {1,2,3}, k = 2 it will be {{1,2},{3}} since difference in sum is 0 . The problem is similar to The Partition Problem from The Algorithm Design Manual . Except Steven Skiena discusses a method to solve it without rearrangement. I was going to try Simulated Annealing. So i

Seeking a solution or a heursitic approxmation for the 3-partition combinatorial situation

由 ♀尐吖头ヾ 提交于 2019-12-07 20:55:49
问题 How do I distribute 48 items each with its own dollar value to each of 3 inheritors so that the value given to each is equal or nearly equal? This is a form of partitioning problem with is NP-complete (or some such) and therefore impossible to perfectly answer with 48 items. I'm looking for a practical and generally acknowledged approximate algorithm to do this. It's a problem faced by many in resolving wills and estates. Answer must be out there somewhere! The answer could be a computer

How to partition a set of values (vector) in R

由 徘徊边缘 提交于 2019-12-07 07:46:12
问题 I'm programming in R. I've got a vector containing, let's say, 1000 values. Now let's say I want to partition these 1000 values randomly into two new sets, one containing 400 values and the other containing 600. How could I do this? I've thought about doing something like this... firstset <- sample(mydata, size=400) ...but this doesn't partition the data (in other words, I still don't know which 600 values to put in the other set). I also thought about looping from 1 to 400, randomly removing

SQL Server Partition per table on Tenant ID - disk space used

由 放肆的年华 提交于 2019-12-06 13:19:08
问题 We are currently developing a Multi Tenant web application. This application stores all it's data in 1 single database. Datarows for a tenant are always with the tenant id. At the moment we are considering creating table partitions, with the tenant id as partitioning key. This makes sense because 99.9% of all queries will include the tenant id as a where clause criterium. If I understand correctly, SQL Server query optimize all such queries by eliminating the table partitions that not contain

Windows Azure table access latency Partition keys and row keys selection

由 六月ゝ 毕业季﹏ 提交于 2019-12-06 12:19:11
问题 We've got a windows azure table storage system going on where we have various entity types that report values during the day so we've got the following partition and row key scenario: There are about 4000 - 5000 entities. There are 6 entity types and the types are roughly evenly distributed. so around 800'ish each. ParitionKey: entityType-Date Row key: entityId Each row records the values for an entity for that particular day. This is currently JSON serialized. The data is quite verbose. We

Seeking a solution or a heursitic approxmation for the 3-partition combinatorial situation

由 陌路散爱 提交于 2019-12-06 07:28:34
How do I distribute 48 items each with its own dollar value to each of 3 inheritors so that the value given to each is equal or nearly equal? This is a form of partitioning problem with is NP-complete (or some such) and therefore impossible to perfectly answer with 48 items. I'm looking for a practical and generally acknowledged approximate algorithm to do this. It's a problem faced by many in resolving wills and estates. Answer must be out there somewhere! The answer could be a computer script or just a manual method. A heuristic that is "Generally Accepted" would suffice. With my programmer

Windows Azure table access latency Partition keys and row keys selection

由 时光总嘲笑我的痴心妄想 提交于 2019-12-04 19:41:13
We've got a windows azure table storage system going on where we have various entity types that report values during the day so we've got the following partition and row key scenario: There are about 4000 - 5000 entities. There are 6 entity types and the types are roughly evenly distributed. so around 800'ish each. ParitionKey: entityType-Date Row key: entityId Each row records the values for an entity for that particular day. This is currently JSON serialized. The data is quite verbose. We will periodically want to look back at the values in these partitions over a month or two months

Slice a PowerShell array into groups of smaller arrays

由 核能气质少年 提交于 2019-12-04 14:42:33
I would like to convert a single array into a group of smaller arrays, based on a variable. So, 0,1,2,3,4,5,6,7,8,9 would become 0,1,2 , 3,4,5 , 6,7,8 , 9 when the size is 3. My current approach: $ids=@(0,1,2,3,4,5,6,7,8,9) $size=3 0..[math]::Round($ids.count/$size) | % { # slice first elements $x = $ids[0..($size-1)] # redefine array w/ remaining values $ids = $ids[$size..$ids.Length] # return elements (as an array, which isn't happening) $x } | % { "IDS: $($_ -Join ",")" } Produces: IDS: 0 IDS: 1 IDS: 2 IDS: 3 IDS: 4 IDS: 5 IDS: 6 IDS: 7 IDS: 8 IDS: 9 I would like it to be: IDS: 0,1,2 IDS: 3
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