Groovy's Sql and DataSet classes could support batch operations

Attached patch which adds withBatch capability

attached slightly modified spike file from Witold Szczerba - not ready for consumption in its current form

The withBatch method from SqlBatch.patch has been added to trunk and the 1_6_X branch.

The withBatch method in 1.7 beta does not support generation of a prepared statement from a GString. This is essential to prevent the need for:
1. escaping of string values
2. database locale-dependent string representation of dates, timestamps and numbers

I believe this feature is included in 1.7.

http://groovy.codehaus.org/(draft)+Groovy+1.7+release

@Kenneth: Re: I believe this feature is included in 1.7.
Part of the functionality from the above patches was included in 1.7 but not all.
We will add some more batch capability once we get time to add in the remaining patches and test them.

More specifically, the current withBatch aggregates a whole bunch of individual queries/commands to the database into a batch which gives greater efficiency. The functionality still to implement would partition a very large insert/update into smaller batch sizes. E.g. inserting 10,000 records may be done as 20 batches of 500.

Potential patch to allow a batch size to be set on withBatch. Batches partitioned into chunks that size.

Still not a final solution for DataSets - could be used but doesn't support prepared statements, so not ideal.

I split out all of the stuff related to using Statement.executeBatch() into GROOVY-4146. This issue is now specifically just about batching of PreparedStatements which isn't supported by the Java libraries directly and would need to be rolled on top of those libraries. I also moved some of the attachments into GROOVY-4146.