Querying the Space
This section explains the various mechanisms offered by GigaSpaces XAP to query the space for data:
- ID query - Retrieve objects from the Space based on the Primary Key.
- Query by template - Find data based on template matching (a.k.a. Match by example).
- SQL query - The SQLQuery class is used to query the space using SQL-like syntax.
- SQL Function - You can query the Space using built-in and user-defined functions.
- Geospatial query - Use geometry data types such as points, circles and polygons (these queries consider the spatial relationship between the geometries).
- Nested property query - Use SQL queries on nested properties, maps and collections.
- Query with user-defined classes - Query by matching a user-defined class.
The following related topics describe how to use indexing to boost query performance, and how the Space can be iterated to fetch entries more efficiently:
- Paging support - Reading a large number of objects using multiple queries in one call, in a continuous manner.
- Partial results - Projection - You can obtain partial results when querying the Space, to improve application performance and reduce the memory footprint.
- Explain Plan - This can be used to obtain a description of the strategy or plan that XAP uses to implement a specific SQLQuery.