[HACKERS] WIP Patch: Pgbench Serialization and deadlock errors

Hello, hackers!

Now in pgbench we can test only transactions with Read Committed 
isolation level because client sessions are disconnected forever on 
serialization failures. There were some proposals and discussions about 
it (see message here [1] and thread here [2]).

I suggest a patch where pgbench client sessions are not disconnected 
because of serialization or deadlock failures and these failures are 
mentioned in reports. In details:
- transaction with one of these failures continue run normally, but its 
result is rolled back;
- if there were these failures during script execution this 
"transaction" is marked
appropriately in logs;
- numbers of "transactions" with these failures are printed in progress, 
in aggregation logs and in the end with other results (all and for each 
script);

Advanced options:
- mostly for testing built-in scripts: you can set the default 
transaction isolation level by the appropriate benchmarking option (-I);
- for more detailed reports: to know per-statement serialization and 
deadlock failures you can use the appropriate benchmarking option 
(--report-failures).

Also: TAP tests for new functionality and changed documentation with new 
examples.

Patches are attached. Any suggestions are welcome!

P.S. Does this use case (do not retry transaction with serialization or 
deadlock failure) is most interesting or failed transactions should be 
retried (and how much times if there seems to be no hope of success...)?

[1] 
https://www.postgresql.org/message-id/4EC65830020000250004323F%40gw.wicourts.gov
[2] 

https://www.postgresql.org/message-id/flat/alpine.DEB.2.02.1305182259550.1473%40localhost6.localdomain6#alpine.DEB.2.02.1305182259550.1473@localhost6.localdomain6

-- 
Marina Polyakova
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers