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

When was Recurrent Neural Network proposed ?
SELECT DISTINCT paper.year FROM keyphrase, paper, paperkeyphrase WHERE keyphrase.keyphrasename = 'Recurrent Neural Network' AND paperkeyphrase.keyphraseid = keyphrase.keyphraseid AND paper.paperid = paperkeyphrase.paperid GROUP BY paper.year ORDER BY paper.year
SELECT DISTINCT "paper"."year" FROM "keyphrase" JOIN "paperkeyphrase" ON "keyphrase"."keyphraseid" = "paperkeyphrase"."keyphraseid" JOIN "paper" ON "paper"."paperid" = "paperkeyphrase"."paperid" WHERE "keyphrase"."keyphrasename" = 'Recurrent Neural Network' GROUP BY "paper"."year" ORDER BY "paper"."year"