[DERBY-2876] Ensure the DataTypeDescriptor.comparable() implements the correct rules for determing the collation to use.

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 10.3.1.4, 10.4.1.3
• Component/s: SQL
• Assignee: Unassigned
• Reporter: Daniel John Debrunner
• Created: 26/Jun/07 19:45
• Updated: 29/Apr/08 18:13
• Resolved: 29/Apr/08 18:13

Description

The current implementation of comparable requires that collation type and derivation must match for the types to be comparable.
This is not correct according to SQL Standard 9.13, e.g. with non-matching types and one derivation of implicit and one of none, then the types are comparable.

Possibly this method is not the correct location for this functionality, as no indication can be given of the correct collation to use, just if they are comparable or not.

Would be fixed by a correct implementation of the 9.13 rules under DERBY-2875, but that's marked as an improvement.
This issue is to record the fact that the comparision logic is currently incorrect and so DERBY-1478 is not yet complete.

Issue Links

• relates to: DERBY-2875 Check if collation determination logic can be consolidated in one central place rather than multiple places in the compile package