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

Michael T. Dean mtdean at thirdcontact.com
Fri Apr 22 16:55:34 UTC 2011

On 04/22/2011 08:01 AM, Richard Morton wrote:
> of course the amount of previous recordings

That you haven't deleted :)

>   is also a factor; so your
> database will grow with age. mine is now about 2 years old (I am
> shocked to discover). From mythweb statistics page.

# du -hs /srv/mysql/mythconverg/
531M    /srv/mysql/mythconverg/

Database size is never something you have to worry about--MythTV 
automatically cleans up garbage in it.

And your database size will generally reach a steady state within one 
year of use.  At that point, all growth is due to increasing the number 
of seconds of *current* recordings in MythTV or the number of seconds of 
MythVideo videos /with seek tables/.  In other words, after a year of 
use, the only tables that will really grow are the ones that store the 
MythTV and/or MythVideo seek tables.  All other data--listings, 
recording history, settings (regardless of number of hosts), ...--is a 
negligible amount of data.

Once you've reached the one-year point, the only way to decrease the 
size of your database is to delete recorded/MythVideo video (meaning 
delete their associated seek tables).  However, this is obviously 
destructive--you lose the video.

As proof, I've been using my current MythTV database since May 3, 2004, 
and of the 531MiB shown, my recorded seek table and associated index is 

# ls -alS {recordedseek,filemarkup}.*
-rw-rw---- 1 mysql mysql 274074750 Apr 22 05:20 recordedseek.MYD
-rw-rw---- 1 mysql mysql 250828800 Apr 22 12:19 recordedseek.MYI
-rw-rw---- 1 mysql mysql      8698 Jun 24  2010 recordedseek.frm
-rw-rw---- 1 mysql mysql      8662 Jun 24  2010 filemarkup.frm
-rw-rw---- 1 mysql mysql      4096 Apr 22 04:38 filemarkup.MYI
-rw-rw---- 1 mysql mysql         0 Apr 22 04:38 filemarkup.MYD

(Note that I don't really use MythVideo, and I don't have any MythVideo 
seek tables--the ones in filemarkup, which is why that's basically 0 
space.)  The 500.6MiB of recorded seek tables correspond to:

1489 programs, using 6.2 TB (1 month 29 days 8 hrs 4 mins)

(at the bottom of the "Recorded Programs" page in MythWeb).  This is the 
only statistic that will really affect the "influenceable" database 
size--assuming you don't create MythVideo seek tables.

Note, also, if you've installed the MythGame ROM DB, it would take about 
27MiB, and you may have around 10MiB or so of Internet content in there, 
if you use MythNetvision.  (I have neither in the above--though I have 
all the plugins installed, I don't own any ROMs, so I have no need to 
install the ROM DB data, and I went into MythNetvision and cleared out 
my MNV subscriptions just to give a better picture of DB usage in MythTV.)

Note, also, that we are planning a change which will reduced the size of 
recorded seek tables by about 40% and will significantly reduce the size 
of the MythVideo (file) seek tables/markup (where seeing 1/10 the 
current size wouldn't be at all surprising).


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