partitioning

Range partition skip check

别说谁变了你拦得住时间么 提交于 2019-12-06 11:36:08
We have large amount of data partitioned on year value using range partition in oracle. We have used range partition but each partition contains data only for one year. When we write a query targeting a specific year, oracle fetches the information from that partition but still checks if the year is what we have specified. Since this year column is not part of the index it fetches the year from table and compares it. We have seen that any time the query goes to fetch table data it is getting too slow. Can we somehow avoid oracle comparing the year values since we for sure know that the

Number clustering/partitioning algorithm

让人想犯罪 __ 提交于 2019-12-06 10:57:05
I have an ordered 1-D array of numbers. Both the array length and the values of the numbers in the array are arbitrary. I want to partition the array into k partitions, according to the number values, e.g. let's say I want 4 partitions, distributed as 30% / 30% / 20% / 20%, i.e. the top 30% values first, the next 30% afterwards, etc. I get to choose k and the percentages of the distribution. In addition, if the same number appears more than once in the array, it should not be contained in two different partitions. This means that the distribution percentages above are not strict, but rather

Partitioning a list of integers to minimize difference of their sums

老子叫甜甜 提交于 2019-12-06 10:21:35
问题 Given a list of integers l , how can I partition it into 2 lists a and b such that d(a,b) = abs(sum(a) - sum(b)) is minimum. I know the problem is NP-complete, so I am looking for a pseudo-polynomial time algorithm i.e. O(c*n) where c = sum(l map abs) . I looked at Wikipedia but the algorithm there is to partition it into exact halves which is a special case of what I am looking for... EDIT: To clarify, I am looking for the exact partitions a and b and not just the resulting minimum

Neo4j partition

拈花ヽ惹草 提交于 2019-12-06 08:41:29
Is the a way to physically separate between neo4j partitions? Meaning the following query will go to node1: Match (a:User:Facebook) While this query will go to another node (maybe hosted on docker) Match (b:User:Google) this is the case: i want to store data of several clients under neo4j, hopefully lots of them. now, i'm not sure about whats is the best design for that but it has to fulfill few conditions: no mixed data should be returned from a cypher query ( its really hard to make sure, that no developer will forget the ":Partition1" (for example) in a cypher query) performance of 1 client

oracle partition by group_id and subpartition monthly

若如初见. 提交于 2019-12-06 08:37:46
I want to create a table like this. create table some_data ( id number(19,0), group_id number(19,0), value float, timestamp timestamp ); For this table i would like to have the data stored like group_id=1 jan-2015 feb-2015 ... group_id=2 jan-2015 feb-2015 ... and so on. So I assume i have to create a partition by range for the group_id and then a subpartition also by range with the timestamp column, right? So it should look like this: create table some_data ( id number(19,0), group_id number(19,0), value float, timestamp timestamp ) PARTITION BY RANGE (group_id) SUBPARTITION BY RANGE (

Remotely extend a partition using WMI

一曲冷凌霜 提交于 2019-12-06 07:00:55
I'm trying to use PowerShell and WMI to remotely extend a C drive partition on Windows VMs running on VMware. These VM do not have WinRM enabled and that's not an option. What I'm trying to do is an equivalent of remotely managing an Active Directory computer object in an AD console to extend a partition, but in PowerShell. I'v already managed to pull partition informations through Win32 WMI objects but not yet the extension part. Does anyone know how to max out a C partition on a drive like that? Pre-requisites: PsExec from SysInternals Suite PowerShell 2.0 or greater for PowerShell modules

Number of all possible groupings of a set of values?

痴心易碎 提交于 2019-12-06 06:32:30
I want to find a combinatorial formula that given a certain number of integers, I can find the number of all possible groupings of these integers (such that all values belong to a single group) Say I have 3 integers, 1, 2, 3 There would be 5 groupings: 1 2 3 1|2|3| 1 2|3 1|2 3 2|1 3 I have calculated these computationally for N = 3 to 11, but I am trying to theoretically assertain. These values are: (I believe they are correct) num_integers num_groupings 3 5 4 15 5 52 6 203 7 877 8 4140 9 21147 10 115975 11 678570 The reason for doing this is to find the total number of partitionings of a

Control data locality in Impala by partitioning

浪子不回头ぞ 提交于 2019-12-06 06:31:41
问题 I would like to avoid Impala nodes unnecessarily requesting data from other nodes over the network in cases when the ideal data locality or layout is known at table creation time. This would be helpful with 'non-additive' operations where all records from a partition are needed at the same place (node) anyway (for ex. percentiles). Is it possible to tell Impala that all data in a partition should always be co-located on a single node for any HDFS replica? In Impala-SQL, I am not sure if the

Creating multiple partitions on USB using C#

血红的双手。 提交于 2019-12-06 06:09:53
问题 Iam trying to use DeviceIOControl to create multiple partiions in USB. It is always creating only one partition. Here is my source code [DllImport("kernel32.dll", SetLastError = true)] static extern IntPtr CreateFile(string lpFileName, uint dwDesiredAccess, uint dwShareMode, IntPtr lpSecurityAttributes, uint dwCreationDisposition, uint dwFlagsAndAttributes, IntPtr hTemplateFile); [DllImport("kernel32")] static extern int CloseHandle(IntPtr handle); [DllImport("kernel32")] private static

Adding partitions to Hive from a MapReduce Job

偶尔善良 提交于 2019-12-06 03:50:58
I am new to Hive and MapReduce and would really appreciate your answer and also provide a right approach. I have defined an external table logs in hive partitioned on date and origin server with an external location on hdfs /data/logs/ . I have a MapReduce job which fetches these logs file and splits them and stores under the folder mentioned above. Like "/data/logs/dt=2012-10-01/server01/" "/data/logs/dt=2012-10-01/server02/" ... ... From MapReduce job I would like add partitions to the table logs in Hive. I know the two approaches alter table command -- Too many alter table commands adding