partitioning | 易学教程

Create a Partition Function in SQL

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问题 I have created a partition function but I am not able to apply it to a table. I am not sure where I am going wrong. Here is my partition function: CREATE PARTITION FUNCTION StaticDateMonthPartition (int) AS RANGE left FOR VALUES ( 20120301, 20120401, 20120501, 20120601, 20120701, 20120801, 20120901, 20121001, 20121101, 20121201, 20130101, 20130201 ) trying to apply to this table: IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[partition_OLAP_Fact_vvv]') AND type in

Initialize and partition disk - how to prevent “you need to format disk” message from appearing?

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问题 I'm trying to initialize, partition and format a disk from application. OS is Windows Server 2008 R2. It doesn't really matter which method do I use for these tasks, but let's assume I'm using DeviceIoControl API. As soon as application initializes and creates a partition Windows would pop a message box saying "You need to format disk... " So, even though my application immediately formats this disk, message box would still be there, and user would be confused, and can actually format it

When to use which mysql partitioning model

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问题 Ok guys, just starting out with partitioning some tables in mySQL. There's a couple of different ways describing this, but what I cant find is a more practical approach. - Which type of data does each way of partitioning have the best effect on? Or doesn't it really matter? Reference: http://dev.mysql.com/tech-resources/articles/performance-partitioning.html 回答1: It depends exactly what kind of performance problem you're having. MySQL 5.1's partitioning only allows you to partition the first

How Partitions are split into Kafka Broker?

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问题 I know that partitions are split across Kafka Broker. But the split is based on what ?. For instance, if I have 3 brokers and 6 partitions, how to ensure that each broker will have 2 partitions ? How this split is currently made in Kafka ? 回答1: Assignment policy is an internal implementation detail and not documented as it can get changed at any point in time. Thus, you should not rely the this algorithms stay the same. Furthermore, there is nothing you can do to influent/configure this

Neo4j partition

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问题 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,

Insert overwrite vs Delete HDFS partition and write parquet file in spark

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问题 Is there any major performance issue for parquet in using hiveContext.sql("INSERT OVERWRITE TABLE table_name PARTITION(dt='2016-06-08', country) , select x,y,z,country from DFTmpTable"); VS DeleteHDFSfile(/table/dt='2016-06-08') DF.write().mode("append").partitionBy("dt","country").parquet("/table/dt='2016-06-08'") 来源： https://stackoverflow.com/questions/39810659/insert-overwrite-vs-delete-hdfs-partition-and-write-parquet-file-in-spark

Create a Partition Function in SQL

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I have created a partition function but I am not able to apply it to a table. I am not sure where I am going wrong. Here is my partition function: CREATE PARTITION FUNCTION StaticDateMonthPartition (int) AS RANGE left FOR VALUES ( 20120301, 20120401, 20120501, 20120601, 20120701, 20120801, 20120901, 20121001, 20121101, 20121201, 20130101, 20130201 ) trying to apply to this table: IF EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].[partition_OLAP_Fact_vvv]') AND type in (N'U')) DROP TABLE [dbo].[partition_OLAP_Fact_vvv] GO CREATE TABLE [dbo].[partition_OLAP_Fact_vvv] (

Number clustering/partitioning algorithm

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问题 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

Explanation of Hoare Partitioning algorithm

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问题 As per the pseudo-code given in many websites, I have written this Hoare partitioning algorithm, which takes an array, the start and end indexes of the sub-array to be partitioned based on the pivot given. It works fine, but can somebody explain the logic, how it does what it does? Here' the code: def hoare(arr,start,end): pivot = 4 i,j = start,end while i < j: while i < j and arr[i] <= pivot: i += 1 while j >= i and arr[j] > pivot: j -= 1 if i < j: arr[i],arr[j] = arr[j],arr[i] return j

Filtering a spark partitioned table is not working in Pyspark

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问题 I am using spark 2.3 and have written one dataframe to create hive partitioned table using dataframe writer class method in pyspark. newdf.coalesce(1).write.format('orc').partitionBy('veh_country').mode("overwrite").saveAsTable('emp.partition_Load_table') Here is my table structure and partitions information. hive> desc emp.partition_Load_table; OK veh_code varchar(17) veh_flag varchar(1) veh_model smallint veh_country varchar(3) # Partition Information # col_name data_type comment veh