Comments (4)
a float64 floatfield has only 52 bits for the number the rest is for the exponent, so only 32 bit integers can be stored, this is Okay for most values, but we have to drop INT64 and UINT64 data types. I'm not sure what would be the performance penalty for having a char or textfield as column in the DB, but i suspect for bigger queries it would be not so good. With the new option to have more than one data table/backend would it be possible to have a separate Table for variables that have to store data as str?
from pyscada.
Ok, so we need 3 fields:
- BigIntegerField for integers (with the shift technique for unit64),
- FloatField for floats,
- CharField or TextField for strings.
I don't know if there is a performance penalty to have a char or text column for the variable not having data in it, I will try it.
One solution with the new data source architecture could be to separate this in 3 tables:
- RecordedDataInteger,
- RecordedDataFloat,
- RecordedDataString.
One question is what should the manager do if the variable value class is:
- string and the value to store is an integer or a float,
- float and the value to store is an integer or a string,
- integer and the value is a float or a string ?
from pyscada.
One question is what should the manager do if the variable value class is:
in my opinion either drop the value and throw an error or convert to the appropriate data type
from pyscada.
Ok so finally all the values of a variable will be in only one table.
from pyscada.
Related Issues (20)
- Recorded Data init : not looking for value class UINT64 HOT 21
- Various variable value class with the same key HOT 4
- Replace Variable color selection
- API HOT 41
- No log file HOT 13
- How to retrieve variable value HOT 2
- Custom Html Variable Not Showing HOT 1
- Questions for installation HOT 2
- Pyscada Django Issue HOT 23
- Failed to start PyScada Daemon HOT 6
- Modbus write into a Force Single Coil (FC5) HOT 1
- Can we install PyScada on Windows? HOT 3
- Can't start pyscada HOT 15
- Problems using PyScada for modbus device HOT 4
- 能看下界面组态效果吗 HOT 1
- I Want use it on Django>=4 HOT 2
- I wish I can get in touch with people involve in this project. HOT 1
- Table pyscada_db.pyscada_deviceprotocol doesnt exist HOT 5
- Not sure why https://github.com/pyscada/PyScada-File is empty HOT 2
Recommend Projects
-
React
A declarative, efficient, and flexible JavaScript library for building user interfaces.
-
Vue.js
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
-
Typescript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
-
TensorFlow
An Open Source Machine Learning Framework for Everyone
-
Django
The Web framework for perfectionists with deadlines.
-
Laravel
A PHP framework for web artisans
-
D3
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
-
Recommend Topics
-
javascript
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
-
web
Some thing interesting about web. New door for the world.
-
server
A server is a program made to process requests and deliver data to clients.
-
Machine learning
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
-
Visualization
Some thing interesting about visualization, use data art
-
Game
Some thing interesting about game, make everyone happy.
Recommend Org
-
Facebook
We are working to build community through open source technology. NB: members must have two-factor auth.
-
Microsoft
Open source projects and samples from Microsoft.
-
Google
Google ❤️ Open Source for everyone.
-
Alibaba
Alibaba Open Source for everyone
-
D3
Data-Driven Documents codes.
-
Tencent
China tencent open source team.
from pyscada.