example solr configurartion file

[Jae Joo]

does anyone know what exactly is?
<mergeFactor>10</mergeFactor>
    <maxBufferedDocs>10000</maxBufferedDocs>
    <maxMergeDocs>2147483647</maxMergeDocs>
    <maxFieldLength>10000</maxFieldLength>
    <writeLockTimeout>1000</writeLockTimeout>
    <commitLockTimeout>10000</commitLockTimeout>

If we change the value, do I have to reindex it?

Thanks,

Jae