Disappearing Indexes

[DiFaz]

I've got a client who has indexes disappearing. They called me last week, and all but one index on a table had disappeared. I rebuilt the indexes and told them to keep me posted

They called again today, and said the same thing had happened. When I looked at the table only three of the indexes were still there. out of 11! (Yes, they need all 11)

Then when I went in and added all of the indexes back in and asked it to rebuild the indexes, I got the message "You didn't make any changes. Rebuild all indexes?"

Any Ideas?

[Tom Cone Jr]

RE: Disappearing Indexes

Ray,

Check the versions they are using throughout the office. Are they all using v. 4.5, or are some using earlier versions?

-- tom

[JerryBrightbill]

RE: Disappearing Indexes

Ray,

When Alpha tries to evaluate an index expression and gets an error, it drops the index. Also, any index names longer than 10 characters are saved in the data dictionary. If that has become corrupted in any way, the index name may be lost, and a truncated name will be displayed. Then, if you try to reference the index, alpha can only find the short name, not the name you probably are looking for.

I would start by compacting the database (never hurts), rebuilding the indexes, check any expressions for problems (like references to a field that was deleted - did that once), ands if all else fails, reinstall backup copies of the index fiels (cdx) and data dictionaries (ddd, ddm, ddx) for the table and then rebuild the indexes.

Another possibility is just a corrupted index file. Delete the cdx file for the table completely. Compact the database. Then reopen the table, go to define indexes, and reenter new indexes.

There have been many posts on lost indexes. A couple good rules to follow are

1. Keep all index names to 10 characters or less
2. Avoid filters in indexes if possible
3. No variables in indexes
4. Avoid including values that can change frequently, or ones that refer to something outside the table and can change without the record actually being changed, like date().

Jerry

[Bill Warner]

RE: Disappearing Indexes

I had a similar problem with a client using a network. I had a button on the main menu to update indexes. However, I found that it would update the indexes on the local machine, NOT on the server. Here's how I fixed it:

IF :a5.get_master_path()=""
path=:a5.get_path()
else
path=:a5.get_master_path()
END IF

tbl = table.open(path+chr(92)+"members.dbf")index_create_begin("Idnum", "IDNUM") ...etc

Also, follow Jerry's guidelines.

[csda1]

RE: Disappearing Indexes

Hi Ray,

It sounds more like the index file or the database is corrupted.

1st delete the index file (table.cdx) outside of A5, then recreate the file.

If that doesn't work, you may want to check the table itself for corruption with a dbf checker (I still use FileFix from DOS PCTools and DOS Norton Utilities)

If that doesn't work, see if there is any place you drop (delete) an index in your code. If there is, see if the code is being activated at unexpected times.

Regards,

Ira J. Perlow
Computer Systems Design & Associates
[email protected]

[Greg Fong]

RE: Disappearing Indexes

Where can I get a copy of these programs? Are there other programs like this around?