CreateIndexStmt <- Unique? 'INDEX' IfNotExists? IndexName? 'ON' BaseTableName IndexType? Parens(List(IndexElement)) WithList? WhereClause?

WithList <- 'WITH' Parens(List(RelOption)) / Oids
Oids <- ('WITH' / 'WITHOUT') 'OIDS'
IndexElement <- Expression DescOrAsc? NullsFirstOrLast?
Unique <- 'UNIQUE'
IndexType <- 'USING' Identifier
RelOption <- ColLabel ('.' ColLabel)* ('=' DefArg)?
DefArg <- FuncType / ReservedKeyword / StringLiteral / NumberLiteral / 'NONE'
FuncType <- Type / ('SETOF'? TypeFuncName '%' 'TYPE')