DBI: speed up insertions in generating database

[punch_card_don]

Malkovitchian Monks, I am populating a mysql databse programmatically, analyzing a giant text file and then inserting into one of the many tables.

pseudo code:

open FILE
while ($line = FILE) {
     analyze $line to extract ($table, $value) pairs
     foreach ($table_$value_pair) {
          $sql = "INSERT INTO ".$table." VALUES(".$value.")"
          prepare
          execute()
     }
}

This works, but is very slow. I can't get around the repeated prepares because the table changes with each iteration and there is way too much data (~1Gb) to hold it all in table-keyed hashes ready for a table-wise insertion at the end.

One option I'm considering is doing it in blocks, storing for a while, then purging:

open FILE
$index = 0;
while ($line = FILE) {
     analyze $line to extract ($table, $value) pairs
     push each found $value onto $values_hash{$table} as 2-d array so 
+$values_hash{$table} = a list of $values
     $index++;
     when $index reaches, say, 10,000 or 100,000 {
          foreach $key (keys $values_hash) {
               $sql = "INSERT INTO ".$table." VALUES(?)"
               prepare
               foreach $value in list $values_hash{$key} 
                    execute($value)
               }
          }
     clear $values_hash ready to start storing again
     }
}

I figure this should help, but not sure how much I will actually gain by that.

Are the are any other slick speed tricks? I vaguley remember something to do with pre-generating csv files and then importing....