Hi,
the current spec allows specifying a query timeout on a Query, a PM or a
PMF. The PM defines the default for all Query instances of the PM and
the PMF defines the default value for all PMs of that PMF. However,
there are still three open issue in the query timeout area:
(1) query timeout as an optional feature
I propose to add query timeout as an optional feature. This means the
collection returned by the PMF method supportedOptions includes the
string "javax.jdo.option.QueryTimeout", if the JDO implementation and
the datastore bound to the PMF supports query timeout. This would be a
change in chapter 11.6 "Optional Feature Support" of the spec.
(2) Scope of the query timeout value
I propose that a query timeout value set for a PM applies to all
"datastore query" operations issued by the PM. This includes
relationship navigation, findByObjectId and lasy loading of collections.
But how about modifying operations such as update, delete and insert?
Does it make sense to apply the PM's query timeout for these
operationsas well? I think this makes sense, but it might be less
obvious, because these operations are part of the transaction commit.
See also Jörg's recent email with subject "update timeout". This would
be a change in chapter 12 PersistenceManager. Today chapter 12.6.3
"Query factory interface" specifies method setQueryTimeout. If we
broaden the scope of a query timeout set on a PM, it might make sense to
specify this in its own section, e.g. 12.6.9 "Query Timeout".
(3) Definition of query timeout: datastore operation or JDO method?
Does the query timeout apply to the underlying datastore operation or
does it define the maximum execution time of the JDO method such as
Query.execute?
I propose the former, meaning use the query timeout value for the
datastore operation. Otherwise, the JDO implementation would need to
calculate the timeout for the datastore operation and need o guess the
time needed to post-process the query result. If the datastore has the
JDBC standard second resolution, and there is less than 1000 millis left
in the timeout, what should be the timeout set on the datastore query
statement?
What do you think?
Regards Michael
--
*Michael Bouschen*
*Prokurist*
akquinet t...@spree GmbH
Bülowstr. 66, D-10783 Berlin
Fon: +49 30 235 520-33
Fax: +49 30 217 520-12
Email: [email protected]
Url: www.akquinet.de <http://www.akquinet.de>
akquinet t...@spree GmbH, Berlin
Geschäftsführung: Martin Weber, Prof. Dr. Christian Roth
Amtsgericht Berlin-Charlottenburg HRB 86780 B
USt.-Id. Nr.: DE 225 964 680
--
*Michael Bouschen*
*Prokurist*
akquinet t...@spree GmbH
Bülowstr. 66, D-10783 Berlin
Fon: +49 30 235 520-33
Fax: +49 30 217 520-12
Email: [email protected]
Url: www.akquinet.de <http://www.akquinet.de>
akquinet t...@spree GmbH, Berlin
Geschäftsführung: Martin Weber, Prof. Dr. Christian Roth
Amtsgericht Berlin-Charlottenburg HRB 86780 B
USt.-Id. Nr.: DE 225 964 680
--
*Michael Bouschen*
*Prokurist*
akquinet t...@spree GmbH
Bülowstr. 66, D-10783 Berlin
Fon: +49 30 235 520-33
Fax: +49 30 217 520-12
Email: [email protected]
Url: www.akquinet.de <http://www.akquinet.de>
akquinet t...@spree GmbH, Berlin
Geschäftsführung: Martin Weber, Prof. Dr. Christian Roth
Amtsgericht Berlin-Charlottenburg HRB 86780 B
USt.-Id. Nr.: DE 225 964 680
