CREATE TABLE writes (paperid NUMBER, authorid NUMBER)
CREATE TABLE paper (paperid NUMBER, title VARCHAR2, venueid NUMBER, year NUMBER, numciting NUMBER, numcitedby NUMBER, journalid NUMBER)
CREATE TABLE field (fieldid NUMBER)
CREATE TABLE venue (venueid NUMBER, venuename VARCHAR2)
CREATE TABLE cite (citingpaperid NUMBER, citedpaperid NUMBER)
CREATE TABLE author (authorid NUMBER, authorname VARCHAR2)
CREATE TABLE keyphrase (keyphraseid NUMBER, keyphrasename VARCHAR2)
CREATE TABLE paperfield (fieldid NUMBER, paperid NUMBER)
CREATE TABLE dataset (datasetid NUMBER, datasetname VARCHAR2)
CREATE TABLE journal (journalid NUMBER, journalname VARCHAR2)
CREATE TABLE paperdataset (paperid NUMBER, datasetid NUMBER)
CREATE TABLE paperkeyphrase (paperid NUMBER, keyphraseid NUMBER)

authors with at least 5 papers
SELECT DISTINCT COUNT(paper.paperid), writes.authorid FROM paper, writes WHERE writes.paperid = paper.paperid GROUP BY writes.authorid HAVING COUNT(paper.paperid) >= 5
SELECT DISTINCT COUNT("paper"."paperid"), "writes"."authorid" FROM "paper" JOIN "writes" ON "paper"."paperid" = "writes"."paperid" GROUP BY "writes"."authorid" HAVING COUNT("paper"."paperid") >= 5