Lost Indexes

[James Smith]

I know this problem has visited this forum many times, but I think I am following all of the 'dos' and don'ts' correctly, yet I'm still losing my indexes on a daily basis.
I've created 5 indexes for a table. None of the indexes are filtered, none are over 9 characters long. The indexes are used as follows:

I have several different forms based on the same table. The same 5 fields appear on all of the forms. I'm using a great tip from Bill Warner "To use a button for the field label...".
Bill's script for a button is as follows:

dim global jobno as c
parentform.index_set("job")
jobno = ui_get_text("JOB NUMBER", "Enter Job Number", jobno)
If jobno = ""
END
END IF
parentform.find(jobno)

When my customer used the new forms with buttons defined as above, on the first day they got the "Your indexes may have become corrupted..." message and all the indexes I had created disappeared. So I modified the script by using
"dim jobno as c" rather than "dim global jobno as c"
and I use a differrent variable (but same index) for the same field on different forms.
For example to find by FileName on one form I use:

dim mfilename as c
parentform.index_set("FileName")
etc.

and on another form I would use:

dim vfilename as c
parentform.index_set("FileName")
etc.

I modified the script because I did not want the message box to display previous values and I hoped it would also fix the disappearing index problem.
No such luck. Still losing the indexes.
Note: not all of the indexes disappear. There are actually 6 indexes...the first one "inv_no" I think,was created by A5, and the next "filename", "address", "city", "hometel", and "worktel" are the indexes I created. Only the 5 I created disappear.

Thanks
Jim Smith

[forskare]

RE: Lost Indexes

Jim,

What version are you using? A5v4.5?

kenn

[Tom Patten]

RE: Lost Indexes

Jim,

The five you created - did you create them in the table define indexes area?

How did you name them? The name may conflict with Alpha's need to create indexes. I begin all indexes I create with a z prefex.

When you use the line of script:

parentform.index_set("job")

it assumes you have an index called "Job"

Tom

[James Smith]

RE: Lost Indexes

I'm using V4.5 and the index names are the same as the field names...filename, address, city, hometel, worktel.

thanks
Jim Smith

[James Smith]

RE: Lost Indexes

Yes, I created indexes in the "Define Indexes" area then rebuilt all indexes. The index names are the same as the field names...filename, address, city, hometel, worktel. Indexes were used as follows, for example:

parentform.index_set("filename")

Thanks
Jim Smith

[Tom Cone Jr]

RE: Lost Indexes

Jim,

Could you post a working model here for us to examine?

-- tom

[forskare]

RE: Lost Indexes

Jim,

I think that's what Tom P is talking about. Alpha may be getting confused. Rename the indexes beginning with the letter z and see if that solves the problem. If not, can you post a zip file as our sun burned friend TC requests?

kenn

[JerryBrightbill]

RE: Lost Indexes

Jim,

Tom has good advice. Post a working copy and someone should be able to come up with some ideas. Normally, indexes disappear for specific reasons. If the index expression can't be evaluated, the index is dropped. If alpha tries to open two indexes at once, one index may be dropped. This could happen if you specify a filter or order in form properties and also specify an index on the OnInit event. You could also run into a problem if you specify a query that matches an existing index definition. There should be no need to do this, and I have never tested this one, but it is one other instance that could cause an conflict.

One situation where the index name can be a problem is if a reserved or restricted name is used. An example would be naming an index "date". If you refer to this in a script, alpha could confuse the index name with the function date(). Another name that have given a problem is "select". Adding a prefix will eliminate this issue. The default name to an index is the field name it is based on, so this should not cause problems.

Another interesting issue occurs if the index is generated by Alpha. Examples include indexes for set definitions, form filters, lookups, etc. In a couple cases, I have renamed these indexes only to find that Alpha renames them back to the original name. Now I just leave them with whatever cryptic name is generated by the program. If you have another index that you create, be sure the name is different.

Jerry

[James Smith]

RE: Lost Indexes

I could post an example, but without the clients data, I�m not sure how useful it would be. I�ve tried to recreate this problem at home and was unsuccessful, so I spent yesterday at the clients site, watching the operators enter data. There were two different conditions that triggered the problem. One was when an operator opened a form in enter mode then immediately clicked the �find� button to locate a record, so I fixed the find buttons so they do not show up in enter mode. However, I think the 2nd condition is the key problem causer. An operator using one particular machine (which incidentally, has an �old� version of Win95) would only input data a couple of times a day and when he did it was to find a series of 5-30 records one at a time and change one or two field values and then save the changes. He could change a few records then the corrupted index error would begin to show up on just about every record after that. So I rebuilt the indexes, had this operator switched to a different machine, and the problem did not show up for the rest of the day. These people are not big on new hardware and I believe this computer could be 8-10 years old. I remember that the first versions of Win95 had a lot of bugs. Is it possible that this or perhaps a random cpu or memory error could be the source of the index problems?
Thanks to everyone for your input. I really appreciate it.
Jim Smith

[Tom Cone Jr]

RE: Lost Indexes

Jim,

Back when I was using Alpha Four I remember learning about a patch to Windows 95 that was necessary to overcome a problem Win95 was having with locking and unlocking files on local area networks. Don't remember the details, but maybe you can find references to it in the Knowledge Base at Microsoft. Perhaps the offending station needs the same fix?

-- tom