RE: Idea to enhance pgbench by more modes to generate data (multi-TXNs, UNNEST, COPY BINARY)

Hi Boris,

I have reviewed the new patch. Overall, it looks correct,
but I have a few minor questions.

1. What do you think about moving characters in 'detail: Allowed step
characters are: "dtgMScGUvpf"' so that generation modes and
transactions count modes are not mixed? For example "dtMSgcGUvpf".
2. In the initCreateTables function, default values are set as empty
strings '' in the pgbench_history and pgbench_accounts tables. Was
this done intentionally, and if so, what is the reason? In the
pgbench_tellers and pgbench_branches tables, the implicit default
would be NULL - why was this logic changed?
3. In showPopulateTableCopyProgress, I think it would be better to
calculate elapsed_sec and remaining_sec inside the condition blocks,
as is done in the original code.
4. Do the changes and bug fixes in the patch affect performance? Are
the existing performance measurements still valid?

Best regards,
Egor