[rrd-users] Fetching from the beginning of an RRD file

Alex van den Bogaerdt alex at ergens.op.het.net
Fri Mar 2 07:02:03 CET 2007

On Thu, Mar 01, 2007 at 09:49:56PM -0800, Travis Spencer wrote:

> > Think of the database as a wheel.  There is no beginning nor an end.
> OK, but time isn't a wheel; it's linear and on that line epoch occurs
> before the second of January 2007 (the date corresponding to
> 1167724800 that I used in my previous example).

The __DATABASE__ is like a wheel.  Not time, but the stored rates.
There is a fixed amount of positions available (selected, by you
when you built the database).

> While I have no doubt that is how RRD handles things internally, I was
> thinking of it more like this: Each RRD file is a database.  That
> database contains one table for each CF (e.g., AVERAGE, MIN, etc.).
> Each table has a number of columns (e.g., DS, DST, timestamp, etc.).
> Given all of this, I was thinking of my initial example:

Forget all you know about SQL and databases using SQL.
This is RRDtool.  It is not mysql or similar.

Trust me.  Although I may make mistakes from time to time (I'm only
human), chances are my story is more valid than yours.

Alex van den Bogaerdt

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