Another important matter...
I've got more than 300 items, and probably even more (I'm discovering new ones all the time) which MHT content I cannot search, find, etc.
I've noticed that most of these [DON'T] have content in the itemHTMLtext (sometimes there's no text in there but IQ seems to believe there is some, as filters like "itemHTMLtext is not null" will even show emptyish itemHTMLtext fields... anyhow).
That makes one very important aspect of the DB pretty unreliable : searching and finding data...
You could try that experiment. Write in the filter text box of the search grid (no source):
itemHTMLFile and itemhtmlText is null
and see how many items appear.