Re: [HACKERS] Parallel Seq Scan

Hi David and others! David Fetter da...@fetter.org writes: On Tue, Jan 27, 2015 at 08:02:37AM +0100, Daniel Bausch wrote: Tom Lane t...@sss.pgh.pa.us writes: Wait for first IO, issue second IO request Compute Already have second IO request, issue third ... We'd be a lot less

Re: [HACKERS] Parallel Seq Scan

, Daniel -- MSc. Daniel Bausch Research Assistant (Computer Science) Technische Universität Darmstadt http://www.dvs.tu-darmstadt.de/staff/dbausch -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql

Re: [HACKERS] Parallel Seq Scan

... I have done all this two years ago. For TPC-H Q8, Q9, Q17, Q20, and Q21 I see a speedup of ~100% when using IndexScan prefetching + Nested-Loops Look-Ahead (the outer loop!). (On SSD with 32 Pages Prefetch/Look-Ahead + Cold Page Cache / Small RAM) Regards, Daniel -- MSc. Daniel Bausch Research

Re: [HACKERS] State of the on-disk bitmap index

will, because I am going to write about that. Kind regards, Daniel -- Daniel Bausch Wissenschaftlicher Mitarbeiter Technische Universität Darmstadt Fachbereich Informatik Fachgebiet Datenbanken und Verteilte Systeme Hochschulstraße 10 64289 Darmstadt Germany Tel.: +49 6151 16 6706 Fax: +49 6151

Re: [HACKERS] State of the on-disk bitmap index

from 2008 does? I did not look into that. I will at least do something like you just described plus some TPC-H test. As the encoding helps against the cardinality problems, I will also draw comparisons with different cardinalities. Yours sincerely, Daniel -- Daniel Bausch Wissenschaftlicher

Re: [HACKERS] State of the on-disk bitmap index

Am 20.08.2012 09:40, schrieb Albe Laurenz: Daniel Bausch wrote: Hello Jonah, Simon, and the hackers, I am going to implement a simple kind of encoded bitmap indexes (EBI). That is an index type where the bitmap columns may not only contain only a single '1' in the set of bits belonging

Re: [HACKERS] State of the on-disk bitmap index

Am 20.08.2012 11:44, schrieb Daniel Bausch: Actually, I was not involved in writing that paper. I want to use that idea to show something different. I know of a follow up work by Golam Rabilul Alam et al. that uses the query history and data mining on that to optimize for the most common

[HACKERS] State of the on-disk bitmap index

probably. Regards, Daniel -- Daniel Bausch Wissenschaftlicher Mitarbeiter Technische Universität Darmstadt Fachbereich Informatik Fachgebiet Datenbanken und Verteilte Systeme Hochschulstraße 10 64289 Darmstadt Germany Tel.: +49 6151 16 6706 Fax: +49 6151 16 6229 -- Sent via pgsql-hackers