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)

What are the best NLP conferences ?
SELECT DISTINCT COUNT(DISTINCT cite.citingpaperid), paper.venueid FROM cite, keyphrase, paper, paperkeyphrase WHERE keyphrase.keyphrasename = 'NLP' AND paperkeyphrase.keyphraseid = keyphrase.keyphraseid AND paper.paperid = cite.citedpaperid AND paper.paperid = paperkeyphrase.paperid GROUP BY paper.venueid ORDER BY COUNT(DISTINCT cite.citingpaperid) DESC
SELECT DISTINCT COUNT(DISTINCT "cite"."citingpaperid"), "paper"."venueid" FROM "cite" JOIN "paper" ON "cite"."citedpaperid" = "paper"."paperid" JOIN "paperkeyphrase" ON "paper"."paperid" = "paperkeyphrase"."paperid" JOIN "keyphrase" ON "keyphrase"."keyphraseid" = "paperkeyphrase"."keyphraseid" AND "keyphrase"."keyphrasename" = 'NLP' GROUP BY "paper"."venueid" ORDER BY COUNT(DISTINCT "cite"."citingpaperid") DESC