[OPENJPA-2390] HSQLDB SELECT NEXT VALUE FOR Sequence will skip 1 sequence value if allocation size is 1

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.2.1
• Fix Version/s: 2.3.0
• Component/s: jdbc
• Patch Info: Patch Available
• Assignee: Albert Lee
• Reporter: René Link
• Created: 29/May/13 12:40
• Updated: 06/Jun/15 21:19
• Resolved: 24/Jun/13 17:11

Description

The HSQLDictionary sets the DBDictionary.nextSequenceQuery to "SELECT NEXT VALUE FOR

{0} FROM INFORMATION_SCHEMA.SYSTEM_SEQUENCES" when the HSQLDictionary is initialized.

The NativeJDBCSeq uses
_select = MessageFormat.format(format, new Object[]{name, String.valueOf(_allocate * _increment)});
to build the select next value sql. The format is pased 2 arguments "name" and "_allocate * _increment"
but the second is not honored by the nextSequenceQuery.

So when the allocation size is set to 1 the hsqldb nextSequenceQuery statement will return 2 next values
anyway. That is why always one next value will be skipped... 1, 3, 5, 7, and so on.

The nextSequenceQuery should be set with an limit. E.g.
"SELECT NEXT VALUE FOR {0}

FROM INFORMATION_SCHEMA.SYSTEM_SEQUENCES LIMIT

{1}

"

I will attatch an unit test that uses in memory hsqldb to show the problem soon.