Kbase P112410: Why is there a limit on max size for a CLOB/BLOB database data type?
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
26/05/2009 |
|
Status: Verified
GOAL:
Why is there a limit on max size for a CLOB/BLOB database data type?
GOAL:
What are the penalties to set a max limit size way larger than the data in the CLOB/BLOB database data type field?
FACT(s) (Environment):
OpenEdge 10.0B
All Supported Operating Systems
FIX:
The reason there is a limit parameter for blob/clob columns is to provide optional error checking. It allows the database/application designer to set an upper limit that is lower than the maximum storable size of 1 GB, so that an errant application doesn't store some unreasonably large lob when the value is supposed to be small.
For example, if you are storing thumbnail images of something, then it would be wrong for the application to store a full sized image. Or digital signatures, which are also pretty small. Similarly, if you are storing some kind of text in a clob column, it might make sense to limit the size of the text for some application related reason.
The value you set the limit to has no effect on how the data are stored nor on performance. So there are no penalties for setting a limit too much higher than the amount of data stored in the CLOB/BLOB field.