[mythtv-users] How big is your database on disk?

Raymond Wagner raymond at wagnerrp.com
Fri Apr 22 16:37:19 UTC 2011

On 4/22/2011 07:38, Dave Richardson wrote:
>   I'm seeing some slight jumpiness on my frontends when the Guide is
>   accessed during LiveTV.  Having seen some questions recently about
>   optimized queries and indexing, I figured I'd just start with something
>   simple by making sure my database wasn't out of scale to others...
>   I'm curious if anyone feels that this database is average, large,
>   unexpectedly large.

The only two significant contributions to the database are the guide 
data and seek table.  The guide entries are going to be around 300 bytes 
per entry, plus whatever the length of the description.  Figure on 
average, maybe 400 bytes on average for each of tens of thousands of 
entries.  This count is going to be largely static, and directly tied to 
your channel count.

The seek table will be 24 bytes per entry, one entry every keyframe for 
every recording.  Broadcast MPEG2 is typically two keyframes per second, 
so estimate around 170KB per hour of recording.

With one analog (DTA) cable lineup, and one broadcast lineup, I'm 
betting you have around 140 channels, with maybe 60k programs, for maybe 
10.5MB.  That would put you somewhere around 1350 hours of recordings.  
Richard Morton's numbers line up with this, with those 17k tracks in 
MythMusic offsetting some 450 recordings.

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