I think you'll need to show a bit more of what you are trying to do.
I just wrote this simple-minded Perl program, mkbigger.pl, to create mondo tsv files:
```
my $count = shift;
my $head = <>;
my $row = <>;
my @cols = split("\t", $row);
print $head;
for (my $i = 1; $i <= $count; ++$i){
@cols[0] = sprintf("%d", $i);
print join("\t", @cols);
}
```
then had this SQLite3 shell session:
```
SQLite version 3.31.1 2020-01-27 19:55:54
Enter ".help" for usage hints.
Connected to a transient in-memory database.
Use ".open FILENAME" to reopen on a persistent database.
sqlite> create table Biggy7 (id integer primary key autoincrement, a text, b text, c real, d real, e blob, f blob);
sqlite> insert into Biggy7 (a,b,c,d,e,f) values ('a','b',3e8,1.38e-23,x'01',x'02');
sqlite> .mode tabs
sqlite> .headers on
sqlite> .once small.tsv
sqlite> .select * from Biggy7;
sqlite> .q
```
Then, at the OS shell:
```
> perl mkbigger.pl 600000 < small.tsv > vbiggy.tsv
> sqlite3
```
Then, in SQLite shell again:
```
SQLite version 3.31.1 2020-01-27 19:55:54
Enter ".help" for usage hints.
Connected to a transient in-memory database.
Use ".open FILENAME" to reopen on a persistent database.
sqlite> .mode tabs
sqlite> .import vbiggy.txt Bigger
Error: cannot open "vbiggy.txt"
sqlite> .import vbiggy.tsv Bigger
sqlite> .headers on
sqlite> select count(*) as rowCount from Bigger;
rowCount
600000
sqlite>
```
No problem arose with this. Of course, I was not taxing any machine memory limits with this, or working the filesystem much.
You might count the rows you did get in, then go look at your data and see if something special is there, just past the rows that were .import'ed alright.