Measuring memory used by temp_table_size (no replies)

What's a good way to measure the average and max amount of memory being used by temp_table size? For example, if I have temp_table_size = 512MB and allow up to 300 database connections, it looks like 150GB could theoretically be used. In reality, not every query uses the max amount of temp table space. I'd like to measure and see how much non-buffer pool memory is being by temp tables on average and at peak times.

thanks,
Bryan

<code>
mysql> show variables like '%buffer%';
+------------------------------+-------------+
| Variable_name | Value |
+------------------------------+-------------+
| bulk_insert_buffer_size | 67108864 |
| innodb_buffer_pool_instances | 1 |
| innodb_buffer_pool_size | 42949672960 |
| innodb_change_buffering | all |
| innodb_log_buffer_size | 8388608 |
| join_buffer_size | 67108864 |
| key_buffer_size | 67108864 |
| myisam_sort_buffer_size | 67108864 |
| net_buffer_length | 16384 |
| preload_buffer_size | 32768 |
| read_buffer_size | 8388608 |
| read_rnd_buffer_size | 33554432 |
| sort_buffer_size | 67108864 |
| sql_buffer_result | OFF |
+------------------------------+-------------+
</code>