Thema: Delphi Save record to BLOB

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sx2008

Registriert seit: 16. Feb 2008
Ort: Baden-Württemberg
2.332 Beiträge
 
Delphi 2007 Professional
 
#8

Re: Save record to BLOB

  Alt 5. Dez 2009, 16:49
Zitat von nanix:
Speed is the first priority.
Premature optimization is the root of all evil - Donald Knuth.
read more: http://www.codinghorror.com/blog/archives/000061.html
Maybe you save some time storing your data, but you lose very much time if you want to retrieve the data.
Assume you want to read the data for a specific sensor and you know the name of the sensor.
Doing it your way using BLOBs you have to read about 50% of all records to find your sensor.
This is called a full table scan.
A very bad approach.

"generic" is right; you have a database and you should not missuse the database.
Blobs are good for pictures, documents or even files but not for structured data.

And BTW, it seems that your table doesn't have a primary key.
Primary keys are really important.
Tables without primary keys and only a blob field performs very bad.
Without a primary key you can't even delete a record, because the database doesn't know which record should be deleted.

My advice is: throw away all your code and design a clean database with normalized tables.
fork me on Github
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