Querying

[Zacarias]

Hi everyone.

Every development should start setting expectations so I propose to spend a few days discussing the features that querying should have.

As an example, how dynamic should the information stored in a data grid be?. Can stored objects be generic or defined in runtime and how does this affect indexing and/or searching?.

Should we consider index-base query?.

Should be any definition or annotation on the entities to define an indexation, searchable field?.

Should Full text search be just another search? any special treatment?

Pagination

Query hierarchy or search methods with filtering? Any SQL approach?

In my experience I needed a few filters on some atributes of defined entities to make soft searches. Also I made a cache for historic changes of those entities so I had to get the list from an ID and then iterate over the collection to filter it.

I´m not English native speaker so please forgive me if something is not so understandable, please feel free to make any clarification or correction.

Thanks,

Zack

[Talip Ozturk]

> As an example, how dynamic should the information stored in a data grid be?.
> Can stored objects be generic or defined in runtime and how does this affect
> indexing and/or searching?.

We expect that for a given map you insert certain type of values.. if
indexing defined then it is expected that indexed fields are available
in the inserted values.

> Should we consider index-base query?.

Not sure what you mean by index-base query but if your query contains
a field which is indexed then query execution will use the indexed
fields. So your queries are already index-aware. But if you implement
your own Predicate then currently indexes aren't used. We should
extend the API to facilitate index-aware custom predicates.

> Should be any definition or annotation on the entities to define an
> indexation, searchable field?.

@Indexed annotation would be nice.

> Should Full text search be just another search? any special treatment?

We currently don't have any special treatment to text fields but we
should in the future. Imagine a text field with short german abstract
and you are searching for a phrase there. Obviously language depended
indexing is required.


> Pagination

We don't have it yet.

> Query hierarchy or search methods with filtering? Any SQL approach?

You can search field of a field.. even method of a field with SQL
syntax... something like
new SqlPredicate("item.getQuantity > 45");

-talip

[Talip Ozturk]

Guys.. please accept my sincere apologies. I thought the email is sent
to the hazelcast mailing group and answered that way. Very sorry.

-talip