I compared your newer version with your test harness.
If I don't modify the test for fairness
Yours
Insert 251
Dump 112
Mine
Insert 401
Dump 266
If I include the string construction in your benchmark and the variant construction in mine.
Yours
Insert 299
Dump 114
Mine
Insert 504
Dump 257
If I change my select to use the while loop autoindexing like yours (smacks forehead), and fix some execution settings I messed up (and turn on inlining since I'm on LV2010 now).
I get
Insert 352
Dump 181
Considering that mine is handling type information and using varaints, I doubt that I could get mine much closer to yours speed wise. With conversion from strings and to over formats I'd probably do better in some cases (since I can handle blob data directly for instance, and don't need to escape strings that contain ' ).
Some comments on the stuff I noticed poking around your code.
In Fetch All you can put a step before the while loop, then put another step after the fetch. Then you wont have to shrink the Rows by one. Also, I'm not sure if this is true with subroutines, but "rows out" in "fetch record" being within a structure requires labview to cache that indicators value between runs. If you make the change to fetch all this won't matter.
Your multistatement querys can't include strings with ';'.
I worked around that by calling strlen from the standard c library on the pzTail returned from prepare statement (while being careful to make sure the string was required in later labview code). Then subtracting that length from the original length and taking a string subset to be the remaining statements. The proper solution would be to use a helper dll and do the pointer math, to avoid transverseing the string in strlen. But since I use prepared statements it doesn't affect my version much.
And to be nit picky SQLite only has one L.
As for my enviroment, my version currently only works on Win32 based systems. There's no reason I couldn't port it to other things though. I have a 64bit LabVIEW install at home. At work there's an old PXI 1002 box, but I've never used it (I haven't had a good excuse for playing with LabVIEW realtime).