db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Satheesh Bandaram <sathe...@Sourcery.Org>
Subject Re: [jira] Commented: (DERBY-1109) lang/predicatePushdown.sql fails with wsdd5.6
Date Tue, 14 Mar 2006 20:00:11 GMT

Mike Matrigali wrote:

> Hopefully someone with some language expertise can comment, I am not
> sure how query processing is doing the "distinct" scan result set.

DistinctScanResultSet seems to be simple extension on HashScanResultSet,
with one difference being ignoring duplicates for the first one. (as
expected) So, guess your answer provides a good explanation...

Satheesh

> I
> know that store provides a way to return a result set as a hash table
> and that hash table is just the standard java provided hash table for
> whatever is the current jvm, with special support for duplicate items
> - if this is what "Distinct Scan ResultSet" is using then it is
> expected that ordering may differ
> based on OS/JVM.
>


Mime
View raw message