On Thu, Apr 28, 2011 at 12:17 AM, Kevin Grittner <Kevin.Grittner@xxxxxxxxxxxx> wrote: > > Dhimant Patel <drp4kri@xxxxxxxxx> wrote: > > > I am a new comer on postgres world and now using it for some > > serious (at least for me) projects. I have a need where I am > > running some analytical + aggregate functions on data where > > ordering is done on Date type column. > > > > From my initial read on documentation I believe internally a date > > type is represented by integer type of data. This makes me wonder > > would it make any good to create additional column of Integer type > > and update it as data gets added and use this integer column for > > all ordering purposes for my sqls - or should I not hasitate using > > Date type straight into my sql for ordering? > > I doubt that this will improve performance, particularly if you ever > want to see your dates formatted as dates. > > > Better yet, is there anyway I can verify impact of ordering on > > Date type vs. Integer type, apart from using \timing and explain > > plan? > > You might be better off just writing the code in the most natural > way, using the date type for dates, and then asking about any > queries which aren't performing as you hope they would. Premature > optimization is often counter-productive. If you really want to do > some benchmarking of relative comparison speeds, though, see the > generate_series function -- it can be good at generating test tables > for such things. There is a lot of really good advice here already. I'll just add one thought. If the dates in your tables are static based only on creation (as in only a CREATE_DATE, which will never be modified per row like a MODIFY_DATE for each record), then your thought might have made sense. But in that case you can already use the ID field if you have one? In most real world cases however the DATE field will likely be storing an update time as well. Which would make your thought about numbering with integers pointless. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
