A.12.1 PGQL Features Supported in Property Graph Schema
PGQL is a SQL-like query language for querying property graph data. It is based on the concept of graph pattern matching and allows you to specify, among other things, topology constraints, paths, filters, sorting and aggregation.
The Java API for PGQL defined in the oracle.pg.rdbms.pgql
package
supports the PGQL specification with a few exceptions. (Refer to
the PGQL Specification).
The following table describes the list of supported and unsupported PGQL features:
Table A-1 Supported PGQL Features and Limitations for PG Schema Graphs
Feature | PG Schema |
---|---|
CREATE PROPERTY
GRAPH |
Supported |
DROP PROPERTY
GRAPH |
Supported |
Fixed-length pattern matching | Supported |
Variable-length pattern matching goals | Supported:
|
Variable-length pattern matching quantifiers | Supported:
|
Variable-length path unnesting | Not supported |
GROUP
BY |
Supported |
HAVING |
Supported |
Aggregations | Supported:
Limitations:
|
DISTINCT
|
Supported |
SELECT
v.* |
Not Supported |
ORDER BY (+ASC/DESC),
LIMIT, OFFSET |
Supported |
Data Types | Supported:
|
JSON | No built-in JSON support.
However, JSON strings (VARCHAR2 )
can be mapped into
NVARCHAR2(15000) data
type.
|
Operators | Supported:
Limitations:
|
Functions and predicates | Supported:
Limitations:
|
User-defined functions | Not supported |
Subqueries:
|
Supported:
Limitations:
|
GRAPH_TABLE operator
|
Not supported |
INSERT/UPDATE/DELETE |
Supported for Oracle Database 19c and later |
INTERVAL
literals and operations
|
Not supported |
The following explains a few PGQL features that require special consideration.