4 ms·

Are you sure about that? https://www.postgresql.org/docs/9.1/sql-cluster.html https://www.postgresql.org/docs/9.1/sql-cluster.html

• polskibus 8y ago
  That's not how a real clustered primary key works, because "the changes are not clustered.".
  • asah 8y ago
    can confirm. That said, one can often capture much of the performance benefit with Postgres indexes - basically, instead of trying to tightly-pack the base tables, copy the data into indexes which are tightly packed exactly as you need. Put another way, Postgres indexes are synchronously updated materialized views - and yes, the Postgres planner/optimizer will automatically answer queries from an index if it's faster and all the columns are in there. I esp recommend reading about function and expression indexes, as well as the (new) covering indexes. http://blog.scoutapp.com/articles/2016/05/31/3-postgresql-indexing-tricks-that-surprise-everyone http://blog.scoutapp.com/articles/2016/05/31/3-postgresql-in... https://www.endpoint.com/blog/2013/06/10/postgresql-functional-indexes https://www.endpoint.com/blog/2013/06/10/postgresql-function... https://paquier.xyz/postgresql-2/postgres-11-covering-indexes/ https://paquier.xyz/postgresql-2/postgres-11-covering-indexe...
    • polskibus 8y ago
      Surely the writes will be much slower if you have to copy the data to the index
      • Tostino 8y ago
        What do you think a (non clustered) index is? Of course it slows down writes.
        • polskibus 8y ago
          It was a reply to proposed workaround, to show that it still has significant drawbacks