# Database design help **URL:** \ **Category:** Ignition\ **Created:** [July 9, 2010, 5:23pm UTC](https://forum.inductiveautomation.com/t/database-design-help/2022 "2010-07-09T17:23:06Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![jaepark](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@jaepark](https://forum.inductiveautomation.com/u/jaepark)\ **Post date:** [July 9, 2010, 5:23pm UTC](https://forum.inductiveautomation.com/t/database-design-help/2022/1 "2010-07-09T17:23:06Z")
We have 20 furnaces and 10 presses, each has between 1 and 10 datapoints that are recorded. How should these data points be saved in a SQL database? Using transaction groups, all the data would be stored in one table with each data point being a column. Would it be better to separate each furnace into its own table? Or should I use the SQL Historian tag option? Data is collected once per minute on the furnaces and every 5 seconds on the presses. ---
**Author:** ![Colby.Clegg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/colby.clegg/32/3282_2.png) [@Colby.Clegg](https://forum.inductiveautomation.com/u/Colby.Clegg)\ **Post date:** [July 9, 2010, 5:39pm UTC](https://forum.inductiveautomation.com/t/database-design-help/2022/2 "2010-07-09T17:39:46Z")
If there is a good amount of overlap in what the data points represent for each furnace, I would lean towards a setup with 1 transaction group per furnace, all writing to the same table, but inserting a row per group- using an action item to write an identifier for the furnace id. You should try to align the columns as much as possible. For example, I imagine each furnace has a temperature data point. There should be one “temperature” column. You use the “furnace\_id” column to specify which one you want to query. You could use sqltags history, but this situation is pretty much ideal for transaction groups: a set of data that you want to record together, repeated for multiple devices. Regards, ---
**Author:** ![jaepark](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@jaepark](https://forum.inductiveautomation.com/u/jaepark)\ **Post date:** [July 12, 2010, 4:17pm UTC](https://forum.inductiveautomation.com/t/database-design-help/2022/3 "2010-07-12T16:17:05Z")
Thank you for the reply Colby. What is an “action item”? I know I need a furnace ID, which I can get from the Furnace table in the database. Would you be able to give an example of using an action item? Do I need to manually assign the ID? Should I use the historical transaction group or standard? What about naming the columns in the database? Should I have the temperatures recording into these columns (since a furnace can have a max of 6 points) TimeStamp, FurnaceID, T1, T2, T3, T4, T5, T6 or TimeStamp,FurnaceID,F1T1, F1T2, F2T1, F3T1, F3T2, F3T3 (Furnace1 Temp1, Furnace1 Temp2, Furnace2 Temp1, …) ---
**Author:** ![Colby.Clegg](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/colby.clegg/32/3282_2.png) [@Colby.Clegg](https://forum.inductiveautomation.com/u/Colby.Clegg)\ **Post date:** [July 12, 2010, 4:59pm UTC](https://forum.inductiveautomation.com/t/database-design-help/2022/4 "2010-07-12T16:59:49Z")
> [@](#): > > TimeStamp, FurnaceID, T1, T2, T3, T4, T5, T6 Yes, exactly. In your second option, the "furnaceid" column doesn't serve a purpose, you're encoding the furnace id into the column names (you may have not intended to include it). This is generally not considered good design- the first is preferred. I guess "Action Item" is a bit of a dated term now- in Ignition they're called "expression items" in groups. The main point is that in each group that is storing data for a furnace, you'll need a way to specify the id. Expression items are likely how you would do this, as they can just be static values as well. So yes, I suspect you would manually assign them. Hope that helps,