craft_searchindex is MyISAM all others InnoDB Looking at my database today notice this one table is MyISAM and also seems huge relative to all other tables with 147,835 rows.  Is that normal?  Shouldn't all tables be InnoDB?  What would cause one to be MyISAM?
The searchindex table has to be MyISAM because up until MySQL 5.6.4, MyISAM was the only engine that supported full text search indexing.

Craft currently supports back to MySQL 5.1.

It is normal for that table to be large because it's keeping a record of every searchable thing on your web site.