[
https://issues.apache.org/jira/browse/EMPIREDB-213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14175049#comment-14175049
]
Rainer Döbele commented on EMPIREDB-213:
----------------------------------------
Hi Ivan,
thanks for your suggestion. This shows one good side of Empire-db: you can
always override and improve things for your own purpose.
The question is: Do we want to make a change to the base implementation that is
the default behavior?
At the moment I am not sure, whether this is necessary.
It's a tradeoff between performance and memory.
Regards
Rainer
> DBReader performance improvement with field caching
> ---------------------------------------------------
>
> Key: EMPIREDB-213
> URL: https://issues.apache.org/jira/browse/EMPIREDB-213
> Project: Empire-DB
> Issue Type: Improvement
> Reporter: Ivan Nemeth
>
> DBReader can be much faster for resultsets with many columns if the
> getFieldIndex(ColumnExpr c) method uses some kind of caching. The following
> code is 10 times faster for a resultset with 20000 rows and 70 columns.
> public class MyDBReader extends DBReader {
> private static final long serialVersionUID = 1L;
>
> private Map<ColumnExpr, Integer> fieldIndices = new HashMap<ColumnExpr,
> Integer>();
> @Override
> public int getFieldIndex(ColumnExpr column) {
> Integer i = fieldIndices.get(column);
> if (i == null){
> i = super.getFieldIndex(column);
> fieldIndices.put(column, i);
> }
> return i;
> }
>
> }
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
