columnstore

Why does the presence of primary key on the table significantly enhance the performance of column-store indexes?

由 匆匆过客 提交于 2019-12-21 19:58:27
问题 I was trying to see the kind of performance gains column-store indexes can provide on a table. The table has about a 3.7 million rows, 11 columns and is stored as a heap (i.e without a primary key). I create a column-store index on the table and run the following query: SELECT [Area], [Family], AVG([Global Sales Value]) AS [Average GlobalSalesValue], COUNT([Projected Sales]) FROM dbo.copy_Global_Previous5FullYearSales WHERE [Year] > 2012 GROUP BY [Area], [Family] The create table statement is

SQL Server 2012 Performance Issue

由 隐身守侯 提交于 2019-12-13 06:39:21
问题 we have a performance issue with our SQL Server 2012 Enterprise setup that I am unable to explain and I am hoping you guys have an idea. We have a fact table with a bunch of int columns that we aggregate as well as a region dimension table. This is the structure of our fact table: regionId (int) revenue (Decimal 10,2) orderIntake (Decimal 10,2) And this is the structure of our dimension table: worldRegion(varchar(100)9 cluster (varchar(100)) country (varchar(100)) regionId (int) The fact

How to install MariaDB ColumnStore in Kubernetes?

由 試著忘記壹切 提交于 2019-12-11 15:54:22
问题 I have been trying to install MariaDB ColumnStore in my kuberentes cluster without any success. I just can't seem to find any information (which at least I can make sense of) on how to do it. Previously I have installed the row base MariaDB using helm helm install stable/mariadb Which installs everything correctly. Is there a way to install ColumnStore using helm? By perhaps designing the values.yaml file? Anyone who has done this before? UPDATE: This is what I tried doing instead. git clone

SQL Server columnstore index update/insert in stored procedure

由 不问归期 提交于 2019-12-10 20:57:39
问题 I was having fun testing out the columnstore index feature of sql server 2012. Because you can't update/insert tables with such indices I read on some options: keep a separate table and use a new partition for every bulk insert or disable the index, perform updates/inserts and then rebuild the index. For my test I chose the latter option and ended up with this stored procedure: -- Disable the columnstore index. ALTER INDEX [All_Columns_Columnstore_Index] ON [dbo].[Tick] DISABLE -- Insert data

How to create primary keys in ClickHouse

由 独自空忆成欢 提交于 2019-12-07 05:42:12
问题 I did found few examples in the documentation where primary keys are created by passing parameters to ENGINE section. But I did not found any description about any argument to ENGINE, what it means and how do I create a primary key. Thanks in advance. It would be great to add this info to the documentation it it's not present. 回答1: Primary key is supported for MergeTree storage engines family. https://clickhouse.yandex/reference_en.html#MergeTree Note that for most serious tasks, you should

How to create primary keys in ClickHouse

由 不打扰是莪最后的温柔 提交于 2019-12-05 11:28:46
I did found few examples in the documentation where primary keys are created by passing parameters to ENGINE section. But I did not found any description about any argument to ENGINE, what it means and how do I create a primary key. Thanks in advance. It would be great to add this info to the documentation it it's not present. Primary key is supported for MergeTree storage engines family. https://clickhouse.yandex/reference_en.html#MergeTree Note that for most serious tasks, you should use engines from the MergeTree family. It is specified as parameters to storage engine. The engine accepts
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