I have taken over a project with minimal knowledge on how to use Azure Data Factory so need some help. The data factory is copying data from one postgres sql server over to my azure sql server. It is running 3 times a day and inserts new rows perfectly. But when data has changed in postgres it does not update the row as needed in the sink database. Can anyone point me in the right direction?
Since the source are on-premise, you can't use data flow. It means that the tutorial #Mark kromer provided for you doesn't works.
Per my experience in Copy active, we only can copy(insert) the data to sink table, won't update it. I'm afraid to say we can't update rows with copy active.
Related
We are working building a new data pipeline for our project and we have to move incremental updates that happen throughout the day on our SQL servers into Azure synapse for some number crunching.
We have to get updates which occur across 60+ tables ( 1-2 million updates a day ) into synapse to crunch some aggregates and statistics as they happen throughout the day.
One of the requirements is being near real time and doing a bulk import into synapse is not ideal because it takes more than 10 mins to do full compute on all data.
I have been reading about CDC feed into synapse https://learn.microsoft.com/en-us/azure/data-factory/tutorial-incremental-copy-change-data-capture-feature-portal and it is one possible solution.
Wondering if there are other alternatives to this or suggestions for achieving the end goal of data crunching near real time for DB updates.
Change Data Capture (CDC) is the suited way to capture the changes and add to the destination location (storage/database).
Apart from that, you can also use watermark column to capture the changes in multiple tables in SQL Server.
Select one column for each table in the source data store, which you
can identify the new or updated records for every run. Normally, the
data in this selected column (for example, last_modify_time or ID)
keeps increasing when rows are created or updated. The maximum value
in this column is used as a watermark.
Here is the high-level solution diagram for this approach:
Step-by-Step approach is given in this official document Incrementally load data from multiple tables in SQL Server to Azure SQL Database using PowerShell.
I have about 100 tables to which we replicate data, e.g. from the Oracle database.
I would like to quickly check that the data replicated to the tables in db2 is the same as in the source system.
Does anyone have a way to do this? I can create 100 transformations, but that's monotonous and time consuming. I would prefer to process this in a loop.
I thought I would keep the queries in a table and reach into it for records.
I read the data from Table input (sql_db2, sql_source, table_name) and write do copy rows to result. Next I read single record and I read a single record and put it into a loop.
But here came a problem because I don't know how to dynamically compare the data for the tables. Each table has different columns and here I have a problem.
I don't know if this is also possible?
You can inject metadata (in this case your metadata would be the column and table names) to a lot of steps in Pentaho, you create a transformation to collect the metadata to inject to another transformation that has only the steps and some basic information, but the bulk of the information of the columns affected by the different steps is in the transformation injecting the metadata.
Check Pentaho official documentation about Metadata Injection (MDI) and the sample with a basic example of metadata injection available in your PDI installation.
I need to merge with 2 different tables from 2 different azure SQL databases where as these two azure sql database are from same azure sql server.
also for performance imporvement purpose, what I need to do is bulk insert and/or bulk update. also, this will be continous activity. for very first time I have to merge all data which is huge. and then whenever respective topic recivies message, I need to add/update that single record only.
what are the different options to do the same. for both processes.
please help. thanks.
You can use Azure SQL Data Sync to merge those tables located on 2 different databases into a third and new database. You just need to create the table with no records, then use Azure SQL Data Sync with one-way sync from those 2 databases (member databases) to the newly created table on the new database (hub database). On the first sync data will be merged on the new table located on the hub database. Every time a record gets updated, deleted or new record arrive on the member databases then that data change is replicated to the hub database and to the merged table.
To know more about the free Azure SQL Data Sync please read here.
Problem:
I need to get data sets from CSV files into SQL Server Express (SSMS v17.6) as efficiently as possible. The data sets update daily into the same CSV files on my local hard drive. Currently using MS Access 2010 (v14.0) as a middleman to aggregate the CSV files into linked tables.
Using the solutions below, the data transfers perfectly into SQL Server and does exactly what I want. But I cannot figure out how to refresh/update/sync the data at the end of each day with the newly added CSV data without having to re-import the entire data set each time.
Solutions:
Upsizing Wizard in MS Access - This works best in transferring all the tables perfectly to SQL Server databases. I cannot figure out how to update the tables though without deleting and repeating the same steps each day. None of the solutions or links that I have tried have panned out.
SQL Server Import/Export Wizard - This works fine also in getting the data over to SSMS one time. But I also cannot figure out how to update/sync this data with the new tables. Another issue is that choosing Microsoft Access as the data source through this method requires a .mdb file. The latest MS Access file formats are .accdb files so I have to save the database in an older .mdb version in order to export it to SQL Server.
Constraints:
I have no loyalty towards MS Access. I really am just looking for the most efficient way to get these CSV files consistently into a format where I can perform SQL queries on them. From all I have read, MS Access seems like the best way to do that.
I also have limited coding knowledge so more advanced VBA/C++ solutions will probably go over my head.
TLDR:
Trying to get several different daily updating local CSV files into a program where I can run SQL queries on them without having to do a full delete and re-import each day. Currently using MS Access 2010 to SQL Server Express (SSMS v17.6) which fulfills my needs, but does not update daily with the new data without re-importing everything.
Thank you!
You can use a staging table strategy to solve this problem.
When it's time to perform the daily update, import all of the data into one or more staging tables. Execute SQL statement to insert rows that exist in the imported data but not in the base data into the base data; similarly, delete rows from the base data that don't exist in the imported data; similarly, update base data rows that have changed values in the imported data.
Use your data dependencies to determine in which order tables should be modified.
I would run all deletes first, then inserts, and finally all updates.
This should be a fun challenge!
EDIT
You said:
I need to get data sets from CSV files into SQL Server Express (SSMS
v17.6) as efficiently as possible.
The most efficient way to put data into SQL Server tables is using SQL Bulk Copy. This can be implemented from the command line, an SSIS job, or through ADO.Net via any .Net language.
You state:
But I cannot figure out how to refresh/update/sync the data at the end
of each day with the newly added CSV data without having to re-import
the entire data set each time.
It seems you have two choices:
Toss the old data and replace it with the new data
Modify the old data so that it comes into alignment with the new data
In order to do number 1 above, you'd simply replace all the existing data with the new data, which you've already said you don't want to do, or at least you don't think you can do this efficiently. In order to do number 2 above, you have to compare the old data with the new data. In order to compare two sets of data, both sets of data have to be accessible wherever the comparison is to take place. So, you could perform the comparison in SQL Server, but the new data will need to be loaded into the database for comparison purposes. You can then purge the staging table after the process completes.
In thinking further about your issue, it seems the underlying issue is:
I really am just looking for the most efficient way to get these CSV
files consistently into a format where I can perform SQL queries on
them.
There exist applications built specifically to allow you to query this type of data.
You may want to have a look at Log Parser Lizard or Splunk. These are great tools for querying and digging into data hidden inside flat data files.
An Append Query is able to incrementally add additional new records to an existing table. However the question is whether your starting point data set (CSV) is just new records or whether that data set includes records already in the table.
This is a classic dilemma that needs to be managed in the Append Query set up.
If the CSV includes prior records - then you have to establish the 'new records' data sub set inside the CSV and append just those. For instance if you have a sequencing field then you can use a > logic from the existing table max. If that is not there then one would need to do a NOT compare of the table data with the csv data to identify which csv records are not already in the table.
You state you seek something 'more efficient' - but in truth there is nothing more efficient than a wholesale delete of all records and write of all records. Most of the time one can't do that - but if you can I would just stick with it.
I am using SQL Server 2005 SSIS and we are using the Data Flow Task to move data from one table to another. This works well. Now we have another requirement to do data update from the same table using this approach.
Is this possible to use the same approach for as follow:
We have a dataset from Table A based on complex query
We update back to the Table A
The normal query UPDATE INTO is not an option due it takes awhile to process and we can't see the data movement like we did for Data Flow Task.
Any guidance or anything that will be good.
Thanks
either:
write it to a temporay table and do the update into with a single SQL task after you processed everything
break it down into smaller chunks based on SSIS variables and OFFSET and use a FOR/FOREACH LOOP
Read the data with a data source in a data flow task, and use ole db command in the data flow to update the data in the same table. If there is no locking when you read and only row-level locking when you update, that should work