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I am trying to determine which is faster in a SSIS package. I have multiple (100's) csv files that have about 150 columns of scientific precision data (38,20) for different types of scenarios. The table is layed out the same way with some other columns. The data sometimes comes in with whitespace/empty data and I have to change this to null for a data conversion at a later time.
I am trying to determine if I should go with derived columns (150) to turn the data into nulls or use a massive sql update statement for updating each column.
Thoughts? Thank you.
Generally speaking, any time you have a choice of doing a transformation in either the SSIS dataflow, or in TSQL, the TSQL way is usually faster.
However, that's only generally speaking, and the only way to know if it holds true in any specific case is to test it.
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I merged two databases for analyses purposes. One of these databases is out of production, so the data is not changing. The other db is live and continuously growing.
What's the best practice in terms of data management/storage? Do I have to delete all rows and reload + union data from both databases or is there a better way to manage this?
Thanks in advance
Sam
If you know the SSIS then make a package which will check keys and based on that it will inserted only unique rows.
You can easily apply lookup via ssis in source and destination.
Let me know if you need any help
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I am deploying an application at one of our vendor. We have few special character that needs to be removed using a function. Vendor is really slow with any changes that we request.
I have access to one of the configuration table that we use to save configuration table.
I want to save a SQL function in the table column that I will fetch at run-time and will execute it.
I am not sure if its a good programming practice. Please suggest if this should not be used then why or is there any other way to do it?
Database is SQL Server. Suggest if it's a good programming practice.
A better practice would be to write your function in such a way that you don't have to change it every time a new special character pops up.
Instead of writing a function that filters out a predefined set of special characters, why don't you write a function that allows a predefined set of non-special characters? Then you should never have to change it.
you can use a Computed column in sql server, for me it's not a good practice depending on the scenario that you are trying to achieve but I think this might help you
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I have to optimize a bunch of many table and data included SQL queries, and I would like to ask some questions:
1) There are situations, when the same functions are needed in different queries. Which results lower processor time: if the functions are calculated separately in every queries or if it is calculated in one query, and they are linked through each other?
2) When creating queries, which is better in giving table relationships? If I have 1 main query, and all of the other queries are related to that, or if there is a serial connection between all the tables?
The 2 main tables are relatively big (~30MB) Excel-tables.
Thank you in advance.
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What is a delta table in SAP HANA databases?
From initial googling, I understood that these tables are some kind of intermediate tables to help data go from one state to another. But when exactly are they used? How are they different from "normal" tables in HANA databases?
Delta tables are a SAP-HANA specific technique to speed up write operations in the database.
Tables in SAP HANA usually use the column store, which is read-optimized. When writing data to a column-store table, this data is first stored in the delta-space for that table; this delta-space is periodically merged into the column store.
See e.g. https://cookbook.experiencesaphana.com/bw/operating-bw-on-hana/hana-database-administration/system-configuration/delta-merge/column-store/ for more details.
"Delta" is commonly used to mean "difference". A delta table would show only the differences between two tables, the records that were added/deleted/changed during the new process. It's a way to test new code to see what changes it caused.
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i'm wanting to write data into memory only for a temp time. the format is essentially the same as an sql table with say 5 columns and 1,000 rows, give or take. simply i want to store this data and run queries against it to make calculations, sorting it, querying it to then produce chart reports and excel data.
I looked at custom psobjects and then sql and i can't see why i'd use custom psobjects over sql, what do you think?
I also couldn't see that adding multiple rows as such, using psobjects was as straight forward as adding another row in sql.
thanks
steve
I guess it depends on what you're more comfortable with, but if you're going to do it in Powershell then using PS custom objects seems like a logical choice since the cmdlets were designed to work with those.