NCT Controller has to resequence a San Carlos arrival due to conflicting San Francisco arrival traffic. The SFO arrival Controller had previously received a pointout on the SQL arrival.

Narrative

I was working Licke/Hooks [sectors] combined. A Meridian was handed off to me from Morgan sector; inbound to SQL at 6;000 FT. The aircraft was requesting the RNAV Z approach via AMEBY waypoint. I pointed out the aircraft via automation to 1T (Toga); 2W (Woodside); 1N (Moffett Tower); and 1P (Palo Alto Tower). I cleared the aircraft for the RNAV Z approach. When the Meridian was just outside of AMEBY; I noticed a tracked target on a Woodside Tag. I clicked on it and it was a turboprop; turning what appeared to be base leg to SFO; descending out of 4;600 FT. It was to the northwest and was going to cross the Meridian's flight path going left to right. I canceled the approach clearance to the Meridian and turned him to a heading of 030 and told him to maintain 4;000 FT. I asked Toga to stop any SJC departures and told them of my intentions to circle the aircraft back to AMEBY. I circled the Meridian back to AMEBY and re-cleared the aircraft for the RNAV Z approach. I then switched the aircraft to SQL Tower. I recommend that the airspace used by Toga over Palo Alto and Moffett be increased from 'surface to 3;000 FT' to 'surface to 4;000 FT.' This would ensure protection for the SQL RNAV approach over AMEBY at 3;900 FT.