Ha, I also recall this fact about the protobuf DB after all these years

Another Jeff Dean fact should be "Russ Cox was Jeff Dean's intern"

This was either 2006 or 2007, whenever Russ started. I remember when Jeff and Sanjay wrote "gsearch", a distributed grep over google3 that ran on 40-80 machines [1].

There was a series of talks called "Nooglers and the PDB" I think, and I remember Jeff explained gsearch to maybe 20-40 of us in a small conference room in building 43.

It was a tiny and elegant piece of code -- something like ~2000 total lines of C++, with "indexer" (I think it just catted all the files, which were later mapped into memory), replicated server, client, and Borg config.

The auth for the indexer lived in Jeff's home dir, perhaps similar to the protobuf DB.

That was some of the first "real Google C++ distributed system" code I read, and it was eye opening.

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After that talk, I submitted a small CL to that directory (which I think Sanjay balked at slightly, but Jeff accepted). And then I put a Perforce watch on it to see what other changes were being submitted.

I think the code was dormant for awhile, but later I saw someone named Russ Cox started submitting a ton of changes to it. That became the public Google Code Search product [2]. My memory is that Russ wrote something like 30K lines of google3 C++ in a single summer, and then went on to write RE2 (which I later used in Bigtable, etc.)

Much of that work is described here: https://swtch.com/~rsc/regexp/

I remember someone telling him on a mailing list something like "you can't just write your own regex engine; there are too many corner cases in PCRE"

And many people know that Russ Cox went on to be one of the main contributors to the Go language. After the Code Search internship, he worked on Go, which was open sourced in 2009.

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[1] Actually I wonder if today if this could perform well enough a single machine with 64 or 128 cores. Back then I think the prod machines were something like 2, 4, or 8 cores.

[2] This was the trigram regex search over open source code on the web. Later, there was also the structured search with compiler front ends, led by Steve Yegge.