datascroller and db hits

[asookazian]

I read the richfaces ref pdf on rich:datascroller and it doesn't state how many (or when) db hits occur when you use a datascroller with datatable.

what happens when you click on different page #'s in the datascroller control (or next, previous, etc.)? is there a simple filter/refresh to the UI or a db hit and refresh of the UI?

see example below:

<rich:datascroller align="left" for="myList" maxPages="20" rendered="#{noteAction.getNoteLogList().size() > 0}"/>
 <rich:spacer height="30" rendered="#{noteAction.getNoteLogList().size() > 0}"/>
 <rich:dataTable width="483" id="myList" rows="5"
 value="#{noteAction.getNoteLogList()}" var="myRow"
 rendered="#{noteAction.getNoteLogList().size() > 0}">
 <f:facet name="header">
 <rich:columnGroup>
 <h:column>
 <h:outputText styleClass="headerText" value="NoteText" />
 </h:column>
 <h:column>
 <h:outputText styleClass="headerText" value="TimeStamp" />
 </h:column>
 </rich:columnGroup>
 </f:facet>

 <h:column>
 <h:outputText value="#{myRow.noteText}"/>
 </h:column>
 <h:column>
 <h:outputText value="#{myRow.timeStamp}">
 <s:convertDateTime dateStyle="short" timeStyle="medium" type="both"/>
 </h:outputText>
 </h:column>
 </rich:dataTable>

[brachie]

Hi,

per default, the rich:dataTable/dataScroller is working with a list loaded into memory. No database backing. So when you paginate there is no db hit for fetching the rows to show, instead you get a sublist of the list in memory. If you want a lazy loading list backed by a db-query you can search this forum. There are several threads about this topic.

Regards,

Alexander