Pallan was a citizen of the domed city located on the planet P3X-289, in the episode, 7.05 "Revisions".
Pallan's job in the domed city was to monitor the computer system which maintained the dome itself. He was married to Evalla and they seemed to be a happy couple, living simply after their society poisoned their atmosphere with too much industrialization. Pallan and Evalla entertained Daniel and Carter when they came to visit and gave them more information about "the link", a device that each citizen wore which connected them to the archives of their world through the same computer system that controlled the dome.
Pallan showed Carter the computer system and it was then that Carter realized that the dome was shrinking, but Pallan acted as if nothing was wrong and insisted that she was mistaken in her interpretation of the data. Pallan didn't realize that the computer was modifying his memory to coincide with the changes in the dome and, thus, to him, there was nothing to be concerned about.
Finally, after Pallan failed to recognize the name of his wife whom the computer sent out into the toxic wasteland outside the shrinking dome in order to maintain the population, Carter disconnected Pallan from his link and he was able to stop the computer from sending more people to their deaths.
The SGC helped the remaining citizens of the domed city to relocate, but, Pallan would never remember his wife again.
--DeeKayP 17:00, 15 Aug 2004 (PDT)