For questions about Microsoft Azure SQL Data Warehouse, the cloud-based, massively parallel processing database for relational and non-relational data.
Questions tagged [azure-sql-data-warehouse]
48 questions
8
votes
1 answer
What cases benefit from the Reduce, Replicate, and Redistribute join hints?
The From Clause Documentation starting with SQL Server 2008 briefly mention 3 join hints and their basic mechanisms:
Reduce
Replicate
Redistribute
However there does not seem to be much information on when it might become necessary to use…
crokusek
- 2,110
- 4
- 25
- 34
8
votes
5 answers
sys.partitions row count is badly wrong - how to correct this?
Querying sys.partitions can return an approximate row count for a table.
I've noticed that this is returning the same row count for all partitions, regardless of the actual content (even for empty partitions).
The table has a clustered columnstore…
Neil P
- 1,294
- 3
- 20
- 38
7
votes
3 answers
Azure Data warehouse - User defined function issues
Anyone here had luck with creating and using UDFs on Azure data warehouse database? I am in the middle of migrating an on-prem warehouse from SQL Server 2014 to Azure datawarehouse and I ran into an issue with UDFs.
CREATE FUNCTION…
RK Kuppala
- 2,447
- 1
- 22
- 24
5
votes
2 answers
How many rows can SQL Server process in a single INSERT statement into a table?
To illustrate my question, the following is a query detecting order's id which have not been inserted in a data warehouse and inserts them:
With NewOrders
As
(
Select OrderID From Orders
Except
Select OrderID From FactOrders
)
Insert…
Jérôme Verstrynge
- 1,481
- 5
- 23
- 27
5
votes
3 answers
Azure SQL Warehouse - Data Ingestion - Convert a huge fixed width (with commas) file to delimited
I am not even sure if I am framing this question right, but I will try - I have a bunch of huge text files generated from an Oracle export on a Linux system. Each file is about 30 GB in size, and I have about 50 of them.
The goal is to export this…
RK Kuppala
- 2,447
- 1
- 22
- 24
5
votes
2 answers
Add Active Directory User For Azure-SQL-DB
I have an active directory user LDomain\LUser and I want that user to be able to connect to Azure-Sql-DB. The syntax MS uses is throwing an error.
T-SQL:
CREATE USER [LDomain\LUser] FROM EXTERNAL PROVIDER
Error:
Principal 'LDomain\LUser' could…
WhyAShortage
- 141
- 1
- 1
- 7
4
votes
1 answer
Does Azure SQL DW support partitioned views?
I've got a really expensive join in data warehouse that isn't distribution aligned. Unfortunately the join key is nullable, and only half the data has a value, meaning that it wouldn't be a good candidate for the distribution key.
Would be be…
Neil P
- 1,294
- 3
- 20
- 38
4
votes
1 answer
Revision Tracking & Source Control for Azure SQL Data Warehouse
What is a good approaching for tracking incremental changes to database tables, stored procedures, etc for Azure SQL Data Warehouse?
I am in the process of moving a large database over to Azure SQL Data Warehouse. The prior approach for change…
John Hargrove
- 149
- 1
4
votes
2 answers
How Can I Measure How long a query takes on Azure SQL Data Warehouse
In traditional SQL Server I can get CPU and Elapsed Time by setting the following
set statistics time on
When I try that on Azure SQL Data Warehouse I get the following error
Msg 103010, Level 16, State 1, Line 19
Parse error at line: 1, column: 5:…
leemicw
- 143
- 5
3
votes
2 answers
Best practice Azure Datawarehouse for less data-movements
I have a Table with a HASH on a Employee_Key, it also Hold a Date_From and Date_To.
To build the facts I need to change it on a by_date column.
But what is the best practice in Azure DataWarehousing with the less DataMoving as possible.
I've tried…
Harry Leboeuf
- 139
- 3
3
votes
1 answer
How can I obtain the full text for a query that appears in sys.dm_pdw_exec_requests?
I'm trying to tune a DB in Azure SQL Datawarehouse for queries produced by Power BI, which can connect directly to Azure SQL Data warehouse. I'm interested in studying execution plans, tweak things like indexes and statistics, retry queries to test…
Marco Ramírez
- 33
- 3
2
votes
1 answer
How to ignore columns in parquet/polybase import?
I'm using polybase to import a parquet file.
Over time, it is likely we may add or remove named columns in the file.
When I add an additional column, I get the below error:
External file access failed due to internal error: 'File test.parquet:…
Neil P
- 1,294
- 3
- 20
- 38
2
votes
1 answer
Difference between Clustered Columnstore Index Table in Azure SQL and Table in Azure Data Warehouse
What is the essential difference between a Clustered Columnstore Index table in Regular Azure SQL, and a table in Azure Data Warehouse?
They both have columnar storage, no foreign keys, no primary keys , etc. Seems structurally they are the same.…
user161709
2
votes
0 answers
Why does outer apply cause a broadcast move?
I've got an outer apply with a condition on the distribution keys.
select e.a
,e.b
,p1.c
from e
outer apply
(
select top 1
p.DateStamp
from p
where e.distributionKey = p.distributionKey
and p.client =…
Neil P
- 1,294
- 3
- 20
- 38
2
votes
2 answers
Lock a table for a CTAS upsert in Azure SQL DataWarehouse
I have a type 2 dimension in Azure SQL Data Warehouse.
Essentially I am creating an interim table with
CREATE TABLE myDimension_temp
AS
SELECT
...
FROM myStagingTable;
etc
After the CTAS is complete I do a
RENAME OBJECT myDimension TO…
Tom
- 21
- 1