- reduce vector size to 4k, work around for dCache limitation
- reduce vector size to 4k, work around for dCache limitation

mhellmic/davix,EricKTCheung/davix,EricKTCheung/davix,cern-it-sdc-id/davix,mhellmic/davix,mhellmic/davix,cern-it-sdc-id/davix,cern-it-sdc-id/davix,EricKTCheung/davix,cern-it-sdc-id/davix,mhellmic/davix,EricKTCheung/davix