partitioning

来源： https://stackoverflow.com/questions/58806481/what-is-the-maximum-replication-factor-for-a-partition-of-kafka-topic

问题 I am new to Spark, and am working on creating a DataFrame from a Postgres database table via JDBC, using spark.read.jdbc . I am a bit confused about the partitioning options, in particular partitionColumn , lowerBound , upperBound , and numPartitions . The documentation seems to indicate that these fields are optional. What happens if I don't provide them? How does Spark know how to partition the queries? How efficient will that be? If I DO specify these options, how do I ensure that the

问题 Within a bash script i need to get the total disk size and the currently used size of the complete disk. I know i can get the total disk size without needed to be root with this command: cat /sys/block/sda/size This command will output the count of blocks on device SDA. Multiply it with 512 and you'll get the amount of bytes on this device. This is sufficient with the total disk size. Now for the currently used space. I want to get this value without being root. I can assume the device name

问题 Let me explain the context first : I am building a visit tracker, with PHP and MySQL. So when a user visit a certain URL, his informations will be registered, then he will be redirected to a page. Then, when he will click on a link, I will register the information then redirect the user to his destination. So I need to WRITE informations in the database at the moment of the visit. And I need to READ and WRITE informations at the moment of the click. My problem is that I will have many many

问题 Let me explain the context first : I am building a visit tracker, with PHP and MySQL. So when a user visit a certain URL, his informations will be registered, then he will be redirected to a page. Then, when he will click on a link, I will register the information then redirect the user to his destination. So I need to WRITE informations in the database at the moment of the visit. And I need to READ and WRITE informations at the moment of the click. My problem is that I will have many many

问题 Let me explain the context first : I am building a visit tracker, with PHP and MySQL. So when a user visit a certain URL, his informations will be registered, then he will be redirected to a page. Then, when he will click on a link, I will register the information then redirect the user to his destination. So I need to WRITE informations in the database at the moment of the visit. And I need to READ and WRITE informations at the moment of the click. My problem is that I will have many many

问题 We are using Cosmos DB SQL API and here's a collection XYZ with: Size: Unlimited Throughput: 50000 RU/s PartitionKey: Hashed We are inserting 200,000 records each of size ~2.1 KB and having same value for a partition key column. Per our knowledge all the docs with same partition key value are stored in the same logical partition, and a logical partition should not exceed 10 GB limit whether we are on fixed or unlimited sized collection. Clearly our total data is not even 0.5 GB. However, in

问题 I want to partition a dataframe "df1" on 3 columns. This dataframe has exactly 990 unique combinaisons for those 3 columns: In [17]: df1.createOrReplaceTempView("df1_view") In [18]: spark.sql("select count(*) from (select distinct(col1,col2,col3) from df1_view) as t").show() +--------+ |count(1)| +--------+ | 990| +--------+ In order to optimize the processing of this dataframe, I want to partition df1 in order to get 990 partitions, one for each key possibility: In [19]: df1.rdd

问题 I am trying to bring the partitioned data back into the original table. But getting the following error. I swapped the partitioned data into AR_TBCAM.BKP_COST_EVENT_P2016 table via this command ALTER TABLE BKP_COST_EVENT EXCHANGE PARTITION P2016 WITH TABLE AR_TBCAM.BKP_COST_EVENT_P2016 INCLUDING INDEXES WITHOUT VALIDATION; But I want to bring the data back into the TBCAM.BKP_COST_EVENT table. Meanwhile I have split the p2016 into 3 partitions -p2014,p2015,p2016 based on year. As per

问题 This is a follow up from this post. What I am trying to do now is sum the total payments made for the last 6 months. For example, we have this loan as you can see they made 3 payments in the month of April, what I need to do is sum those to get the net amount. Currently my query just finds one of them and takes that one but that is not correct. What I tried to do is this: payments as ( SELECT ROW_NUMBER() OVER(Partition By Account ORDER BY CONVERT(datetime,DateRec) DESC) AS [RowNumber], Total