On Thu, Sep 26, 2013 at 03:23:30PM +0530, Pavan Deolasee wrote: > On Thu, Sep 26, 2013 at 2:05 PM, Pavan Deolasee > <pavan.deola...@gmail.com>wrote: > > > While looking at the compressibility of WAL files generated by pgbench, > > which is close to 90%, I first thought its because of the "filler" column > > in the accounts table. But a comment in pgbench.c says: > > > > /* > > * Note: TPC-B requires at least 100 bytes per row, and the "filler" > > * fields in these table declarations were intended to comply with > > that. > > * But because they default to NULLs, they don't actually take any > > space. > > * We could fix that by giving them non-null default values. However, > > that > > * would completely break comparability of pgbench results with prior > > * versions. Since pgbench has never pretended to be fully TPC-B > > * compliant anyway, we stick with the historical behavior. > > */ > > > > The comment about them being NULL and hence not taking up any space is > > added by commit b7a67c2840f193f in response to this bug report: > > > > http://www.postgresql.org/message-id/200710170810.l9h8a76i080...@wwwmaster.postgresql.org > > > > > On a more careful look, it seems the original bug report complained about > all tables except accounts. And all other tables indeed have "filler" as > NULL. But the way comment is written it seems as if it applies to all DDLs.
Agreed. > Should we just fix the comment and say its applicable for all tables except > accounts ? Please do. -- Noah Misch EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
