The edge version of do_postgres with JRuby causes misterious error like this.

   1   ~ (1) SELECT "id", "digest", "fetched_at", "created_at", "site_id" FROM "pages" WHERE ("site_id" IN (1)) ORDER BY "id"
   2   ~ ERROR: syntax error at or near "("merb : worker (port 4000) ~ ERROR: syntax error at or near "(" - (PostgresError)

The SQL that had been performed is here.

   1  SELECT "id", "digest", "fetched_at", "created_at", "site_id" FROM "pages" WHERE ("site_id" IN (1)) ORDER BY "id"

This is able to be performed successfully at the psql console. So I wonder what the error message means.

Updates

I found the bug.

For example, this code

   1  Page.repository.adapter.execute('SELECT * FROM "pages" WHERE ("id" IN ?) AND ("site_id" = ?)', [1], nil)

generates this sql

   1  SELECT * FROM "pages" WHERE ("id" IN (1)) AND ("site_id" = (NULL))

(NULL) causes parsing error.

This issue happens if the first value is an Array and the succeeding values are not Arrays.

I am very surprised to hear this.

• Eric Veach は Google で AdWords 開発を率いていた! (Eric Veach had led the AdWords team of Google)

Needless to say, Eric Veach is a guru of GI researcher. I have wondered where he vanished after his great doctor thesis. And now I know he was at Google, and used his speciality of probability statistics for the AdWords.

I've been believing that GI problem has very rich context. It can be used as the best tool to think algorithms.