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DataEase 8 - Current Work. Expanding Text field to 4080 characters.

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DataEase 8 - Current Work. Expanding Text field to 4080 characters.

We are currently implementing things to improve both current functionality and backwards compatibility.

LongText
One of the biggest problems for customers migrating from pre 7.x DataEase to 7/8 is the re-assignment of Memo Fields.

Memo Fields in Pre 7.x DataEase is just a big text field built up of a number of 255 long text fields, in 7.x this was moved out of the .DBM data file (i.e.database) and put in a separate file. This allowed users to save much more data in a Memo, but at the same time Memos become dramatically slower.

The problem is not that the New Memo isn't useful or even great (it is, and it is one of the most important features in 8 with WebField, HTMLEdit, MemoClass() etc. etc.), but the old Memo was a large text field and not a Memo (That is why new Memo was needed), and now we no longer have a large text field.

The main difference is of course in speed. By getting a larger Memo you trade it off with slower performance. That is fine if you use it for documents etc, that you don't really manipulate or use in transactions. But what if you have used it for transactions?

With the internal flag for "old" Memo now being taken over by "New" Memo, we either have to implement a new field type or... simply expand text field to 4080characters.

It will have no practical consequences for Text fields 255 or under. It is only if one choose to make a text field larger than 255 that the "LargText" feature kicks in.

Due to limitations in normal DFW functions which can only return 255 some functionality will not be available for the part of the text field that is beyond 255.

We are currently implementing it and before we have tested it thoroughly it is hard to say what will and what won't work. Of the things that doesn't work we will simply make an evaluation of which functions to update to cover the expanded text field. We will not get around the 255 limit for return values so functions like Concat() and JoinText() will be limited, but functions like Lastc,LastW, MidC, MidW will be possible to update to cover the entire string etc.

This is quite extensive and invasive work in PRISM so it will be a while until we come with any further updates to DE8 (A week or too is a while by the way) so our twice weekly routine will be suspended for the duration).


Written by DataEase 17/09/13 at 07:42:10 Dataease [{8}]FIVE