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How do I decrease number of records loaded?
Message
 
 
To
15/11/1999 10:31:04
General information
Forum:
Visual FoxPro
Category:
Databases,Tables, Views, Indexing and SQL syntax
Miscellaneous
Thread ID:
00291211
Message ID:
00291215
Views:
23
Hi Lorne. I have a 250meg table (some records with photos) and it is really fast. Some questions and tips:

Questions:
- What CPU, speed and RAM are you running?
- How fast is LAN connection to your database?
- How are you loading and storing the jgs and what size (in megs) is each one?
- If you you make a copy of the database and empty out all records except one (and pack!) is the system faster?

Tips:
- Without a backend database, you can't really control how many records that VFP loads into memory. You will need a backend database for this.
- Instead of putting your jpegs into the table, separate them into individual files that are named after the primary key in your table. When a record is displayed on the screen call a function to populate the picture or image controls on the screen. This way you control how many jpegs that fox has in memory.
- Reduce the resolution of the jpegs to the minimium acceptable. There are tools to do this that are amazing.

>I recently upgraded an application from 2.6 to VFP 6. With one exception, it is a major improvement. Unfortunatley, the exeption is a major problem. I belive the problem is due to a) in 2.6, a record was only loaded to memory (MEMVAR) when the pointer reached the record. b) it seems in 6, the entire data environment is loaded prior to the window loading. The screen set that is the problem has a data environment approximatley 600 MB ( 600 records, with 2 high res JPG photos per record). This makes load time extremly slow, if there is enough swap space left on the HDD. Unlike remote views, I cannot find a way to force it to only load a few records at a time. This is a read only form set, used to display the data to a TV studio output on live TV. During the broadcast, we use a much better box, but a ten minite data load to recover from a possible crash in the middle of a live broadcast is not tolerable.
>Any suggestions on how to speed the data load or shrink the number of records fetched at one time will be greatly appreciated.
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