1000's of keywords imported - Lightroom Freezes and burns CPU

Question

I imported approx 7000 keywords (most with hierarchical synonyms and some with sub-keywords). In other words a BIG keyword collection.
Now I cannot use Lightroom. When I start it it becomes non-responsive (Windows XP) while burning huge amounts of CPU. I have LOST ACCESS TO MY IMAGE COLLECTION!
Please, please, can someone tell me how to delete ALL KEYWORDS outside of Lightroom, so that when I start it it will be usable again?
I have searched my hard disk an cannot locate any files corresponding to "keywords".

Answer 1

Well, I discovered some things which may be of interest - but no actual solution.
First, I bypassed the problem completely by going back to my last "pre-keyword" catalog backup, then importing the 2 days of image files (including XMP sidecars). This gave me back a responsive Lightroom, with all my (meta)data.
Regarding Lightroom's keywords, I found that they are stored in a table in the catalog, which is actually a SQLite database. The table name is AgLibraryTag. You can install SQLite, then run it on the lrdb file:
sqlite> .schema AgLibraryTag
CREATE TABLE AgLibraryTag (
id_local INTEGER PRIMARY KEY,
id_global UNIQUE NOT NULL,
changeEpoch INTEGER,
dateCreated NOT NULL DEFAULT '',
flattenedParams,
folderInfoCache,
genealogy NOT NULL DEFAULT '',
imageCountCache DEFAULT -1,
kindName NOT NULL DEFAULT '',
lastApplied,
name,
parent INTEGER,
sortDirection,
sortOrder
doing a "select * from..." on this table gives a dump of all my keywords. So...I figured that emptying this table as follows might solve the problem, given that I hadn't actually assigned any keywords to any images:
sqlite> delete from AgLibraryTag;
sqlite> select * from AgLibraryTag;
sqlite> vacuum;
sqlite> .exit
WRONG! Lightroom loads, but all my folder information is lost.
I gave up and worked around the problem as noted above, but if anyone from Adobe reads this - you NEED to provide a way to delete large numbers of keywords. If a reasonably high-end WinTel laptop chokes on 7000 keywords then this is NOT usable software.