to improve a query performance, I have decided to partition a relatively Big table by a column date (l_shipdate).
I used synapse spark which was rather a good experience, here is the layout of the new table
now when I try to define a new table using Data Lake Designer, whatever datetime format I assign, I get an errors latter when running a Query either using SQL Serverless or Spark
my Question is what format should I use.
It looks like your issue is the colons in your time value are getting url encoded. Other than that your format is correct.
Related
I am trying to import a small table of data from Azure SQL into Snowflake using Azure Data Factory.
Normally I do not have any issues using this approach:
https://learn.microsoft.com/en-us/azure/data-factory/connector-snowflake?tabs=data-factory#staged-copy-to-snowflake
But now I have an issue, with a source table that looks like this:
There is two columns SLA_Processing_start_time and SLA_Processing_end_time that have the datatype TIME
Somehow, while writing the data to the staged area, the data is changed to something like 0:08:00:00.0000000,0:17:00:00.0000000 and that causes for an error like:
Time '0:08:00:00.0000000' is not recognized File
The mapping looks like this:
I have tried adding a TIME_FORMAT property like 'HH24:MI:SS.FF' but that did not help.
Any ideas to why 08:00:00 becomes 0:08:00:00.0000000 and how to avoid it?
Finally, I was able to recreate your case in my environment.
I have the same error, a leading zero appears ahead of time (0: 08:00:00.0000000).
I even grabbed the files it creates on BlobStorage and the zeros are already there.
This activity creates CSV text files without any error handling (double quotes, escape characters etc.).
And on the Snowflake side, it creates a temporary Stage and loads these files.
Unfortunately, it does not clean up after itself and leaves empty directories on BlobStorage. Additionally, you can't use ADLS Gen2. :(
This connector in ADF is not very good, I even had problems to use it for AWS environment, I had to set up a Snowflake account in Azure.
I've tried a few workarounds, and it seems you have two options:
Simple solution:
Change the data type on both sides to DateTime and then transform this attribute on the Snowflake side. If you cannot change the type on the source side, you can just use the "query" option and write SELECT using the CAST / CONVERT function.
Recommended solution:
Use the Copy data activity to insert your data on BlobStorage / ADLS (this activity did it anyway) preferably in the parquet file format and a self-designed structure (Best practices for using Azure Data Lake Storage).
Create a permanent Snowflake Stage for your BlobStorage / ADLS.
Add a Lookup activity and do the loading of data into a table from files there, you can use a regular query or write a stored procedure and call it.
Thanks to this, you will have more control over what is happening and you will build a DataLake solution for your organization.
My own solution is pretty close to the accepted answer, but I still believe that there is a bug in the build-in direct to Snowflake copy feature.
Since I could not figure out, how to control that intermediate blob file, that is created on a direct to Snowflake copy, I ended up writing a plain file into the blob storage, and reading it again, to load into Snowflake
So instead having it all in one step, I manually split it up in two actions
One action that takes the data from the AzureSQL and saves it as a plain text file on the blob storage
And then the second action, that reads the file, and loads it into Snowflake.
This works, and is supposed to be basically the same thing the direct copy to Snowflake does, hence the bug assumption.
I have a Spark / Databricks job that moves data from the data bricks file system (AVRO files) into an Azure SQL database. Doing this with JDBC works fine (read the data frame from file storage, write it to a JDBC target), but is a little slow.
Microsoft provides a SQLDB Spark driver that has a bulk copy function. If I use this driver and invoke the .write() method, everything works as expected:
df.write.mode(SaveMode.Overwrite).sqlDB(bulkCopyConfig)
However, if I use the bulk copy:
df.bulkCopyToSqlDB(bulkCopyConfig)
it appears that the driver does not handle date fields properly:
om.microsoft.sqlserver.jdbc.SQLServerException: Conversion failed when converting date and/or time from character string.
I've validated that the data frame schema and the table metadata are "correct" or at least as expected; the table layout that the .write() method creates chooses the Azure SQL datetime field for date values, so I used this same structure when prepping the table for the bulkCopy (.write() will create a table, .bulkCopyToSqlDB seems to want the table to already exist).
Any ideas on how to get the bulkCopy to interpret / convert the dates correctly? Do I need to convert them to strings in the dataframe in a different format first?
I need to transform a fairly big database table with aws Glue to csv. However I only the newest table rows from the past 24 hours. There ist a column which specifies the creation date of the row. Is it possible, to just transform these rows, without copying the whole table into the csv file? I am using a python script with Spark.
Thank you very much in advance!
There are some Built-in Transforms in AWS Glue which are used to process your data. This transfers can be called from ETL scripts.
Please refer the below link for the same :
https://docs.aws.amazon.com/glue/latest/dg/built-in-transforms.html
You haven't mentioned the type of database that you are trying connect. Anyway for JDBC connections spark has the option of query, in which you can issue the usual SQL query to get the rows you need.
For moving data from a BigQuery (BQ) table that resides in the US, I want to export the table to a Cloud Storage (GCS) bucket in the US, copy it to an EU bucket, and from there import it again.
The problem is that AVRO does not support DATE types, but it is crucial to us as we are using the new partitioning feature that is not relying on ingestion time, but a column in the table itself.
The AVRO files contain the DATE column as a STRING and therefore a
Field date has changed type from DATE to STRING error is thrown, when trying to load the files via bq load.
There has been a similar question, but it is about timestamps - in my case it absolutely needs to be a DATE as dates don't carry timezone information and timestamps are always interpreted in UTC by BQ.
It works when using NEWLINE_DELIMITED_JSON, but is it possible to make this work with AVRO files?
As #ElliottBrossard pointed out in the comments, there's a public feature request regarding this where it's possible to sign up for the whitelist.
I am trying to find the best way to copy yesterday's data from DocumentDB to Azure SQL.
I have a working DocumentDB database that is recording data gathered via a web service. I would like to routinely (daily) copy all new records from the DocumentDB to an Azure SQL DB table. In order to do so I have created and successfully executed an Azure Data Factory Pipeline that copies records with a datetime > '2018-01-01', but I've only ever been able to get it to work with an arbitrary date - never getting the date from a variable.
My research on DocumentDB SQL querying shows that it has Mathematical, Type checking, String, Array, and Geospatial functions but no date-time functions equivalent to SQL Server's getdate() function.
I understand that Data Factory Pipelines have some system variables that are accessible, including utcnow(). I cannot figure out, though, how to actually use those by editing the JSON successfully. If I try just including utcnow() within the query I get an error from DocumentDB that "'utcnow' is not a recognized built-in function name".
"query": "SELECT * FROM c where c.StartTimestamp > utcnow()",
If I try instead to build the string within the JSON using utcnow() I can't even save it because of a syntax error:
"query": "SELECT * FROM c where c.StartTimestamp > " + utcnow(),
I am willing to try a different technology than a Data Factory Pipeline, but I have a lot of data in our DocumentDB so I'm not interested in abandoning that, and I have much greater familiarity with SQL programming and need to move the data there for joining and other analysis.
What is the easiest and best way to copy those new entries over every day into the staging table in Azure SQL?
Are you using ADF V2 or V1?
For ADF V2.
I think that you can follow the incremental approach that they recommend, for example you could have a watermark table (it could be in your target Azure SQL database) and two lookups activities, one of the lookups will obtain the previous run watermark value (it could be date, integer, whatever your audit value is) and another lookup activity to obtain the MAX (watermark_value, i.e. date) of your source document and have a CopyActivity that gets all the values where the c.StartTimeStamp<=MaxWatermarkValueFromSource AND c.StartTimeStamp>LastWaterMarkValue.
I followed this example using the Python SDK and worked for me.
https://learn.microsoft.com/en-us/azure/data-factory/tutorial-incremental-copy-powershell