[DERBY-6269] Misleading warning text if you create an index duplicating a constraint.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 10.11.1.1
• Component/s: SQL
• Labels: derby_triage10_11
• Urgency: Normal
• Issue & fix info: Repro attached
• Assignee: Mamta A. Satoor
• Reporter: Richard N. Hillegas
• Created: 18/Jun/13 16:02
• Updated: 09/Sep/16 09:52
• Resolved: 06/Oct/14 18:35

Description

If you try to create an index on a column which defines a unique constraint, the index is not created. That's fine. But you get a misleading warning suggesting that the index was created. We should correct the warning text so that it says that an index was not created. We should also consider making this situation an error, not a warning.

This issue is probably related to DERBY-655 and DERBY-1343.

Here is a script which shows this problem:

ij version 10.11
ij> connect 'jdbc:derby:memory:db;create=true';
ij> create table t( a int unique, b int );
0 rows inserted/updated/deleted
ij> – raises a warning suggesting that a new index has been created
create index t_1 on t( a );
0 rows inserted/updated/deleted
WARNING 01504: The new index is a duplicate of an existing index: SQL130618085719940.
ij> – only the heap and the constraint exist
select isIndex, conglomerateName, conglomerateID from sys.sysconglomerates c, sys.systables t
where t.tableid = c.tableid and t.tablename = 'T';
ISIN&|CONGLOMERATENAME |CONGLOMERATEID
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------
false|45b300a8-013f-5801-226b-000003b53310 |0ddd00a9-013f-5801-226b-000003b53310
true |SQL130618085719940 |f55fc0a6-013f-5801-226b-000003b53310

2 rows selected
ij> – fails because a new index wasn't really created
drop index t_1;
ERROR 42X65: Index 'T_1' does not exist.
ij> select isIndex, conglomerateName, conglomerateID from sys.sysconglomerates c, sys.systables t
where t.tableid = c.tableid and t.tablename = 'T';
ISIN&|CONGLOMERATENAME |CONGLOMERATEID
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------
false|45b300a8-013f-5801-226b-000003b53310 |0ddd00a9-013f-5801-226b-000003b53310
true |SQL130618085719940 |f55fc0a6-013f-5801-226b-000003b53310

2 rows selected

Issue Links

• relates to: DERBY-3300 CREATE INDEX that matches an existing index succeeds with a 01504 warning but does not create the index.
• relates to: DERBY-655 getImportedKeys returns duplicate rows in some cases
• relates to: DERBY-1343 It is possible to have duplicate entries in conglomerateId of sysconglomerates before DERBY-655 was fixed in 10.0 or 10.1 databases. It is desirable to patch these databases on upgrade to 10.2 so conglomerateId becomes unique again.