Hi Rob,
>> There seems to be some bugginess between JdbcPkGenerator and
>> MySQLPkGenerator, where JdbcPkGenerator will generate a batch of pks but
>> MySQLPkGenerator only increments the value in the pk cache table by 1
>> instead of by 20 or whatever the cache is. This happens when I override
>> MySQLPkGenerator.getLongPrimaryKey in my own pk generator, but I don't see
>> anything in MySQLPkGenerator.getLongPrimaryKey where it's supposed to update
>> the pk table by the cache size...
I don't see any visible issues with MySQLPkGenerator. The default is 20, and it
is applied via JdbcPkGenerator.pkUpdateString(..). Likely, you do not use
"pkUpdateString(..)" in your overridden method, so it is ignored.
> I ended up just setting pkCacheSize in my pkgenerator constructor.
Yep, that's how it should be done for custom generators.
FWIW, while I have very large projects on MySQL, I never use the PK generator.
All affected tables are modeled using AUTO_INCREMENT with a matching "Database
Generated" PK strategy on the Cayenne side:
CREATE TABLE table (
id MEDIUMINT NOT NULL AUTO_INCREMENT,
name CHAR(30) NOT NULL,
PRIMARY KEY (id)
)
The DB itself takes care of setting unique PKs, and Cayenne simply reads it on
insert. No need for special tables or PK cache strategies.
Andrus
> On Feb 11, 2026, at 11:41 AM, Robert A. Decker <[email protected]> wrote:
>
> I ended up just setting pkCacheSize in my pkgenerator constructor. It
> actually makes more sense there than as a configuration value because it can
> never use the cache because it just doesn't work.
>
> Rob
>
>> On 11 Feb 2026, at 15:53, Robert A. Decker <[email protected]> wrote:
>>
>> I'm on 4.2.1
>>
>> There seems to be some bugginess between JdbcPkGenerator and
>> MySQLPkGenerator, where JdbcPkGenerator will generate a batch of pks but
>> MySQLPkGenerator only increments the value in the pk cache table by 1
>> instead of by 20 or whatever the cache is. This happens when I override
>> MySQLPkGenerator.getLongPrimaryKey in my own pk generator, but I don't see
>> anything in MySQLPkGenerator.getLongPrimaryKey where it's supposed to update
>> the pk table by the cache size... I pretty much just copied the code from
>> MySQLPkGenerator.getLongPrimaryKey so that I could change the table name.
>>
>> Anyway, I could be completely wrong about the bugginess - I haven't
>> confirmed it by running code without my subclass and I'm only going by what
>> I see in the source code.
>>
>> What I really need to know is how I can set the JdbcPkGenerator.pkCacheSize
>> value to 1 (or 0) so that I don't have any caching of pks (I have multiple
>> systems/codebases using the same database).
>>
>> I don't see any way to do it in the DataSourceBuilder while building the
>> cayenne runtime. Do I have to do it in my pkgenerator subclass?
>>
>> Rob
>
>
