That helps, thanks Peter. Regards,
Ruan ________________________________ From: pgsql-general-ow...@postgresql.org <pgsql-general-ow...@postgresql.org> on behalf of Peter J. Holzer <hjp-pg...@hjp.at> Sent: 03 November 2017 08:49 To: pgsql-general@postgresql.org Subject: Re: [GENERAL] EXPLAIN <query> command just hangs... On 2017-11-02 20:51:23 +0000, Rhhh Lin wrote: [...] > where timestamp BETWEEN 1506676560000 AND 1508750220000 [...] > *Also, as a sidenote - can someone please expand on why one (I was not > involved > in the creation of this DB/schema definition) would choose to have the > definition of the timestamp column as a bigint in this case? The numbers look like Java timestamps (Milliseconds since the epoch). So probably the programs accessing the database are written in Java and the programmer decided that it's simpler to do all timestamp computations in Java than in SQL. Or maybe the programmer just felt more comfortable with Java-like timestamps than with calendar dates. (I have done the same (with Unix timestamps, i.e. seconds since the epoch). Although in the cases where I've done it I had the additional excuse that the database didn't support timestamps with timezones, which isn't the case for PostgreSQL.) hp -- _ | Peter J. Holzer | we build much bigger, better disasters now |_|_) | | because we have much more sophisticated | | | h...@hjp.at | management tools. __/ | http://www.hjp.at/ | -- Ross Anderson <https://www.edge.org/> Peter Holzer's Home Page - Peter Johannes Holzer ...<http://www.hjp.at/> www.hjp.at Peter Johannes Holzer ..... was the name my parents chose to have written in my certificate of baptism. Not being content with two Christian names, my fellow men ... [https://www.edge.org/sites/default/files/edge_logo.jpg]<https://www.edge.org/> Edge.org<https://www.edge.org/> www.edge.org To arrive at the edge of the world's knowledge, seek out the most complex and sophisticated minds, put them in a room together, and have them ask each other the ...