Duplicate indexing Nulls about orientdb-gremlin HOT 9 OPEN

Hi @fppt

Since v.2.2 unique indexes also consider null values. You can disable this setting when you create the index setting ignoreNullValues=true, see http://orientdb.com/docs/2.2.x/SQL-Create-Index.html

Anyway, I suggest you not to use it, because indexes without null values cannot be used for some query optimizations, so you will lose performance in some corner cases

Thanks

Luigi

from orientdb-gremlin.

I just checked that docs page, it contains some outdated info. In v 2.2 null values are NOT ignored by default.
I'm fixing it now

Thanks

Luigi

from orientdb-gremlin.

Thanks @luigidellaquila. For the time being is there a way to disable indexing nulls using the available API of this plugin?

from orientdb-gremlin.

How are you creating the index? Is it a single key index?

Thanks

Luigi

from orientdb-gremlin.

I create it as follows:

BaseConfiguration indexConfig = new BaseConfiguration();
indexConfig.setProperty("keytype", OType.String);
indexConfig.setProperty("type", "UNIQUE");
graph.createVertexIndex("prop1", "label1", indexConfig);

from orientdb-gremlin.

I think this should be enough:

BaseConfiguration indexConfig = new BaseConfiguration();
indexConfig.setProperty("keytype", OType.String);
indexConfig.setProperty("type", "UNIQUE");

indexConfig.setProperty("metadata.ignoreNullValues", true);

graph.createVertexIndex("prop1", "label1", indexConfig);

Thanks

Luigi

from orientdb-gremlin.

I added indexConfig.setProperty("metadata.ignoreNullValues", true); no joy sadly. Still getting the same exception.

from orientdb-gremlin.

@luigidellaquila : Can you expand on your statement to not use "unique, ignored-nulls" indexes because of optimization issues in some edge cases? It's something we're doing quite a bit of (in cases where a property is often the same for 99% of the documents, but we need to quickly find the other 1%). I haven't seen any roblems, but I'd like to understand what to watch out for.

from orientdb-gremlin.

Hi @Eric24

The query execution planner used to skip index usages in some conditions, when the index was configured to exclude null values. Anyway, in v 3.0 and with the new execution planner we solved this problem, so it's not a concern anymore

Thanks

Luigi

from orientdb-gremlin.