topic Re: Unique indexes cannot be specified for multiversion tables in Geodatabase Questions

Unique indexes cannot be specified for multiversion tables

HaniDraidi — Tue, 14 Jun 2016 09:22:09 GMT

I have an existing table in an oracle enterprise GDB, when I try to enable this table as versioned, I get an error that says: "unique indexes cannot be specified for multiversion tables".

What might be the issue here?

Any help is highly appreciated!

Hani

Re: Unique indexes cannot be specified for multiversion tables

ChristianWells — Tue, 14 Jun 2016 12:59:33 GMT

Hi Hani,

Do you have any unique indexes specified on your feature class for columns other than OBJECTID?

The reason that multiversion tables cannot support unique indexes is because the delta tables that get created in this operation will support multiple rows for a single OBJECTID. Therefore, a unique index cannot be used as the values in the column will most likely repeat.

For example in table 'Streets' with columns OBJECTID, NAME, LENGTH, SHAPE the following row exists:

1, Main St, 1.234, Shape

If editor 'A' modifies the length field the delta tables will have a new entry:

1, Main St, 2.567, Shape

If editor 'B' modifies it after editor 'A' but changes the length, the new delta table will look like this:

1, Main St, 2.567, Shape

1, Main St, 2.789, Shape

This shows that if a unique index was built on the NAME column, the delta tables would error out frequently with every insert or update.

Re: Unique indexes cannot be specified for multiversion tables

HaniDraidi — Mon, 20 Jun 2016 07:58:38 GMT

Many Thanks Christian for the valuable elaboration.

Actually I don't have unique index on the table. I am wondering if there is any solution for this problem

Your help is highly appreciated!