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

papers about query expansion in sigir 2014
SELECT DISTINCT paper.paperid FROM keyphrase, paper, paperkeyphrase, venue WHERE keyphrase.keyphrasename = 'query expansion' AND paperkeyphrase.keyphraseid = keyphrase.keyphraseid AND paper.paperid = paperkeyphrase.paperid AND paper.year = 2014 AND venue.venueid = paper.venueid AND venue.venuename = 'sigir'
SELECT DISTINCT "paper"."paperid" FROM "keyphrase" JOIN "paperkeyphrase" ON "keyphrase"."keyphraseid" = "paperkeyphrase"."keyphraseid" JOIN "paper" ON "paper"."paperid" = "paperkeyphrase"."paperid" AND "paper"."year" = 2014 JOIN "venue" ON "paper"."venueid" = "venue"."venueid" AND "venue"."venuename" = 'sigir' WHERE "keyphrase"."keyphrasename" = 'query expansion'