Re: [HACKERS] pgbench filler columns
On Fri, Sep 27, 2013 at 4:03 PM, Pavan Deolasee wrote: > On Thu, Sep 26, 2013 at 7:20 PM, Noah Misch wrote: >> >> On Thu, Sep 26, 2013 at 03:23:30PM +0530, Pavan Deolasee wrote: >> >> > Should we just fix the comment and say its applicable for all tables >> > except >> > accounts ? >> >> Please do. >> > > How about something like this ? Patch attached. Thanks! Committed. Regards, -- Fujii Masao -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pgbench filler columns
On Thu, Sep 26, 2013 at 7:20 PM, Noah Misch wrote: > On Thu, Sep 26, 2013 at 03:23:30PM +0530, Pavan Deolasee wrote: > > > Should we just fix the comment and say its applicable for all tables > except > > accounts ? > > Please do. > > How about something like this ? Patch attached. Thanks, Pavan -- Pavan Deolasee http://www.linkedin.com/in/pavandeolasee pgbench_filler_column_notes.patch Description: Binary data -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] pgbench filler columns
On Thu, Sep 26, 2013 at 03:23:30PM +0530, Pavan Deolasee wrote: > On Thu, Sep 26, 2013 at 2:05 PM, Pavan Deolasee > 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
Re: [HACKERS] pgbench filler columns
On Thu, Sep 26, 2013 at 2:05 PM, Pavan Deolasee 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. Should we just fix the comment and say its applicable for all tables except accounts ? Thanks, Pavan -- Pavan Deolasee http://www.linkedin.com/in/pavandeolasee