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Comment by polskibus | Hacker News Reader

Reminds me of .NET's SqlCacheDependency - very useful for cache invalidation, it's been around for while.

See http://msdn.microsoft.com/en-us/library/ms178604.ASPX for details if you are interested.

As someone who is looking for better notification system from database, let me tell you that SqlCacheDependency doesn't cut the cake.

1. SqlCacheDependency uses polling. 2. There is another alternative called SqlDependency which doesn't use polling but it is severely restricted.

http://stackoverflow.com/questions/7588572/what-are-the-limi...

I have looked high and low and could not find any mechanism in SQL Server to send notifications based on the status of arbitrary objects like the original article describes. I would love to be proven wrong about this as I need this functionality bad for the current project I am working on.

Yeah, I saw that and got a good laugh because SQL Server has done that for nearly a decade.

listen/notify was available in postgres 7.1 (and may well have predated it): http://www.postgresql.org/docs/7.1/static/sql-listen.html

7.1 was released in 2001.

edit: digging further, I found this:

    Bug fixes:
        [...]
        * the LISTEN/NOTIFY asynchronous notification mechanism now work

that's in the change list for Postgres95 Beta 0.03, released in July 1995: http://www.postgresql.org/docs/9.3/static/release-0-03.html

This is pretty awesome. One of those things you can do when you own the entire stack.

.NET has the same feature for Oracle and several other databases

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