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Showing posts from November 19, 2018

PostgreSQL increase group by over 30 million rows

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up vote 0 down vote favorite Is there any way to increase speed of dynamic group by query ? I have a table with 30 million rows. create table if not exists tb ( id serial not null constraint tb_pkey primary key, week integer, month integer, year integer, starttime varchar(20), endtime varchar(20), brand smallint, category smallint, value real ); The query below takes 8.5 seconds. SELECT category from tb group by category Is there any way to increase the speed. I have tried with and without index. postgresql performance rdbms database-performance share | improve this question asked Nov 10 at 19:06 ...

Cooperativity

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Cooperativity From Wikipedia, the free encyclopedia Jump to navigation Jump to search This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2009) (Learn how and when to remove this template message) Cooperativity is a phenomenon displayed by systems involving identical or near-identical elements, which act dependently of each other, relative to a hypothetical standard non-interacting system in which the individual elements are acting independently. One manifestation of this is enzymes or receptors that have multiple binding sites where the affinity of the binding sites for a ligand is apparently increased, positive cooperativity, or decreased, negative cooperativity, upon the binding of a ligand to a binding site. For example, when an oxygen atom binds to one of hemoglobin...