Jim Gray, 63, the noted database researcher, a veteran of IBM, Tandem Computers, and, most recently, Microsoft, remained missing at sea last week. He set out Sunday morning, Jan. 28, to sail from San Francisco's Golden Gate Bridge across 27 miles of ocean to the Farallon Islands.

	Gray was sailing alone

I once did a long interview with Gray on parallel processing and database operation. Relational databases presented a good opportunity to take advantage of parallel processing, he said, and patiently explained how both the SQL query and the access of records in the database itself could be broken down into parallel functions.

He had a teacher's patience with my questions. We talked more than an hour, until I felt the subject was exhausted or at least the limits of my understanding had been exhausted. But I felt he was willing to continue and dive deeper, if I had been so inclined. I was grateful for such sharing of knowledge.

Last week, the Coast Guard searched for him across 40,000 square miles of ocean, calling off the search on Feb. 1. The route to the Farallons is straightforward; I've sailed it twice. It follows the commercial shipping channel, marked by buoys, for about half the distance. As you reach the area where the container ships and other commercial vessels take on their San Francisco Bay pilots to guide them through the Golden Gate, you have another 13 to 14 nautical miles to traverse, but as you leave the shoreline behind, there's only an hour or two of open water before the Farallon Islands appear in front of you.

Experienced sailors are asking: Did the greatest calamity that can befall a single-handed sailing vessel occur? That is, did the skipper fall overboard and his boat sail away from him before he could get ahold on it? Single-handers typically wear a harness that keeps them linked to the boat, even if pitched overboard. Besides, we're asking, where's the boat? There are almost always ships within the 22- to 23-mile range that a radio distress signal carries, and no such signal was reported from any quarter. He also carried a beacon that would activate automatically if the boat sank. No beacon signals were picked up.

The weather was clear, the winds were light, the waves 4 to 5 feet high, according to reports. With Gray's 40-foot boat, Tenacious, these conditions should not have presented a big challenge.

I hope Jim Gray will yet be found in some unexpected place. The rudder jammed, and he ended up far off course. Perhaps Tenacious developed a leak that overwhelmed the bilge pump, and he's astride the hull somewhere, waiting to be picked up. Sailboat hulls float, even when waterlogged. But the water is cold. Experienced sailors are worried about Jim Gray.