[DERBY-6117] Extend the Table Functions java interface to pass more query context information from Derby

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 10.8.3.0
• Component/s: SQL
• Labels: derby_triage10_11
• Urgency: Urgent
• Issue & fix info: High Value Fix
• Assignee: Unassigned
• Reporter: David Vyvyan
• Created: 21/Mar/13 15:36
• Updated: 13/Aug/14 15:01

Description

General requirement is to extend the Table Functions java interface (through RestrictedVTI or another interface) and pass more context information from Derby to Table Functions - esp in query execution phase.

Greater urgency is required for the first 2 items below, especially the ability to access the original SQL which was available with VTIs. This is critical to the GaianDB project - we extract HINTs from the query (where we pass meta data like user credentials), and also extract full original complex predicate expressions (involving functions etc - which cannot be expressed with a Restriction) - to push on in our query prorogation...

In order of importance + simplicity:
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1 - Original SQL (this used to be available with VTIs through VTIEnvironment for both compilation and execution phases)
2 - Name of function that was called

3 - User Info (ID, etc) - (this can currently be passed in the SQL hint)
4 - Richer predicate expressions (incl functions, etc)
5 - Context within Join query (e.g. inner or outer table, join type)
6 - Other Query Plan information
7 - Anything else...?

Issue Links

• is related to: DERBY-6467 Document context-aware table functions.