I am quite new to Talend and I need to perform the scd1 operation on snwoflake tables. Can anyone suggest me the important components I need to use in talend to perform this operation. I tried with tDBSCD but it does not allow snowflake database. Is there is any workaround to perform the task. Any help would be appreciated.
Thanks
You need Source Component-->TMap-->Snowflake output Component.
Connect to your normal source and add another source which should be your snowflake target table as a lookup and in TMap you need to join both based on the business key in the TMAP add the variable the SCD columns calculation and add the two targets outputs one for insert and one for the update, In the update link of the snowflake keep the key column and the add merge in the type. And play the job.
Related
There are some records that are missing values. I would like to modify/fill-in data into snowflake from Alteryx. I would like to modify many records at once.
What is the best way to modify snowflake database from Alteryx:
deleting specific rows and append modified data?
modifying data using sql statement in Alteryx output tool?
clone original table --> create modified table --> replace table?
any other ways?
Sincerely,
knozawa
Use an UPDATE statement in Snowflake. There is no benefit to the other methods that you've suggested. When you run an UPDATE in Snowflake, it is recreating the micro-partitions that those records are contained in regardless. Your other methods would be doing that same operation, but more than once. Stick with UPDATE.
I have an SSIS package in which I'm reading the records from a Flat File and storing them in a recordset. Is it possible to compare the values in the recordset with the values in a database table and update the table?
I'm Using SQL Server 2008 R2 and Same version of SSIS.
Leran2002's answer in general is right, the most straight forward way is to have a lookup component set up to Redirect rows to no match output and use a destination and a OLE DB Command afterwards.
However depending on the size of the result sets, this might be slow, since the lookup component will check each row one-by-one and if your destination table has lots of records, this will take some time. Furthermore, depending on your cache settings in the lookup component, it can use lots of memory.
There are two more ways to achieve this:
Merge Join
Using your file source and your destination table as a source, you can use a Merge Join. The logic in the DFT is a bit more complex, but this more a set-based approach and with large result sets it is working better.
You'll have to implement the logic which record has to be updated, inserted, deleted or discarded from the file using a conditional split component.
I highly recommend this question (not exactly your problem, but a good comparison in my opinion): What are the differences between Merge Join and Lookup transformations in SSIS?
Staging table
Another way is to use a staging table to temporarily store the records from a file. In this case, your DFT just loads the records from a file into the staging table, then with one or more Execute SQL Task you can do the merging of the two data sets. (UPDATE, INSERT, DELETE, MERGE, you can use what fits your needs).
Usualy I use Lookup-component with option Redirect rows to no match output.
And after that you can use two rowsets which named Lookup No Match Output and Lookup Match Output.
PS. I have three articles about SSIS, but they in Russian (but there is a lot of SQL-scripts and pictures).
If it's interesting you, you can look the following link - https://habrahabr.ru/post/330618/
We have a large production MSSQL database (mdf appx. 400gb) and i have a test database. All the tables,indexes,views etc. are same eachother. I need to make sure that tha datas in the tables of this two database consistent. so i need to insert all the new rows and update all the updated rows into test db from production every night.
I came up with idea of using SSIS packages to make the data consistent by checking updated rows and new rows in all the tables. My SSIS Flow is ;
I have packages in SSIS for each tables seperately because;
Orderly;
Im getting the timestamp value in the table in order to get last 1 day rows instead of getting whole table.
I get the rows of the table in the production
Then im using 'Lookup' tool to compare this data with the test database table data.
Then im using conditional sprit to get a clue whether the data is new or updated.
If the data is new, i insert this data to the destination
5_2. If the data is updated, then i update the data in the destination table.
Data flow is in the MTRule and STBranch package in the picture
The problem is, im repeating creating all this single flow for each table and i have more than 300 table like this. It takes hours and hours :(
What im asking is;
Is there any way in SSIS to do this dynamically ?
PS: Every single table has its own columns and PK values but my data flow schema is always same. . (Below)
You can look into BiMLScript, which lets you create packages dynamically based on metadata.
I believe the best way to achieve this is to use Expressions. They empower you to dynamically set the source and Destination.
One possible solution might be as follows:
create a table which stores all your table names and PK columns
define a package which Loops through this table and which parses a SQL Statement
Call your main package and pass the stmt to it
Use the stmt as Data Source for your Data Flow
if applicable, pass the Destination Table as Parameter as well (another column in your config table)
This is how I processed several really huge tables: the data had to be fetched from 20 tables and moved to one single table.
You are better off writing a stored procedure that takes the tablename as parameter and doing your CRUD there.
Then call the stored procedure in a FOR EACH component in SSIS.
Why do you need to use SSIS?
You are better off writing a stored procedure that takes the tablename as parameter and doing your CRUD there. Then call the stored procedure in a FOR EACH component in SSIS.
In fact you might be able to do everything using a Stored Procedure and scheduling it in a SQL Agent Job.
I setup a test-bed application vulnerable to mssql injection and i wondered, how do i extract column data from another database? To extract column data from current database we do:
convert(int,(select columnnamegoeshere from tablenamegoeshere))--
and then to enumerate the other column data we do:
convert(int,(select columnnamegoeshere from tablenamegoeshere where columnnamegoeshere not in ('firstentryfromcolumn')))--
But if it's not inside the default database and we want to extract column data from another database, how do we do that? Thanks.
I would do a join... but, to keep it simple for you, here's your code using a different database column:
convert(int,(select columnnamegoeshere from tablenamegoeshere where columnnamegoeshere not in (select top 1 firstentryfromcolumn from otherdb.dbo.otherdbtable)))
It would be better to join the 2 tables together and exclude the records if that's possible... subqueries are usually slower and not the best way to go about it.
I have an SSIS package that I want to use to update a column in a datawarehouse staging table based on the values of a surrogate key mapping table that contains the surrogate key paired with the natural key. Specifically I want to use the cache Lookup to update the fact staging table to contain the surrogate key for the inventory dimention in the same way that the following SQL would.
UPDATE A
SET A.DWHSurrogateKey = B.DWHSurrogateKey
FROM SaleStagingTable A INNER JOIN inventoryStagingTable on B.OLTPInventoryKey = A.OLTPInventoryKey
Unfortunately the nature of the data flow from Lookup transformation to destination means that it creates a whole new row, rather than updating the existing matched row. Is it possible to manipulate SSIS to do this?
Couple of constraints:
My destination is an ADO .NET destination, and we cannot use OLE DB Destinations or sources (we need to be able to use named parameters and you can't do that with OLE DB Connections)
I need to do this for multiple dimensions to link them to the fact table, so I can't just push the mapped data to new tables every time, as that becomes really messy and hard to manage
I'd like to be able to do what these guys have suggested but with ADO connectors rather than OLE DB:
http://redsouljaz.wordpress.com/2009/11/30/ssis-update-data-from-different-table-if-data-is-null/
http://www.rad.pasfu.com/index.php?/archives/46-SSIS-Upsert-With-Lookup-Transform.html
For such a simple update I would use an Execute SQL Task and save the hassle of having to mess around with a data flows. If you have lots of similar updates but with different fields and tables, I would store the column and table names in a Foreach Loop Container using a Foreach Item Enumerator, I would then add a Script Task that would take the item names and generate some dynamic SQL which could be stored in a variable, Next add the Execute SQL Task and get it to use the SQL variable.