title: Merging a large number of csv datasets
body: <p>Here are 2 sample datasets.</p>
  
  <p>PRISM-APPT_1895.csv
  <a href="https://copy.com/SOO2KbCHBX4MRQbn" rel="nofollow">https://copy.com/SOO2KbCHBX4MRQbn</a></p>
  
  <p>PRISM-APPT_1896.csv
  <a href="https://copy.com/JDytBqLgDvk6JzUe" rel="nofollow">https://copy.com/JDytBqLgDvk6JzUe</a></p>
  
  <p>I have 100 of these types of data sets that I'm trying to merge into one data frame, export that to csv, and then merge that into another very large dataset.</p>
  
  <p>I need to merge everything by "gridNumber" and "Year", creating a time series dataset.</p>
  
  <p>Originally, I imported all of the annual datasets and then tried to merge them with this :</p>
  
  <pre><code>df &lt;- join_all(list(Year_1895,    Year_1896,    Year_1897,    Year_1898,    Year_1899,    Year_1900,    Year_1901,    Year_1902,   
                      Year_1903,    Year_1904,    Year_1905,    Year_1906,   Year_1907,    Year_1908,    Year_1909,    Year_1910,   
                      Year_1911,    Year_1912,    Year_1913,    Year_1914,   Year_1915,    Year_1916,    Year_1917,    Year_1918,   
                      Year_1919,    Year_1920,    Year_1921,    Year_1922,   Year_1923,    Year_1924,    Year_1925,    Year_1926,   
                      Year_1927,    Year_1928,    Year_1929,    Year_1930,   Year_1931,    Year_1932,    Year_1933,    Year_1934,   
                      Year_1935,    Year_1936,    Year_1937,    Year_1938,   Year_1939,    Year_1940,    Year_1941,    Year_1942,   
                      Year_1943,    Year_1944,    Year_1945,    Year_1946,   Year_1947,    Year_1948,    Year_1949,    Year_1950,   
                      Year_1951,    Year_1952,    Year_1953,    Year_1954,   Year_1955,    Year_1956,    Year_1957,    Year_1958,   
                      Year_1959,    Year_1960,    Year_1961,    Year_1962,   Year_1963,    Year_1964,    Year_1965,    Year_1966,   
                      Year_1967,    Year_1968,    Year_1969,    Year_1970,   Year_1971,    Year_1972,    Year_1973,    Year_1974,   
                      Year_1975,    Year_1976,    Year_1977,    Year_1978,   Year_1979,    Year_1980,    Year_1981,    Year_1982,   
                      Year_1983,    Year_1984,    Year_1985,    Year_1986,   Year_1987,    Year_1988,    Year_1989,    Year_1990,   
                      Year_1991,    Year_1992,    Year_1993,    Year_1994,   Year_1995,    Year_1996,    Year_1997,    Year_1998,   
                      Year_1999,    Year_2000), 
                      by = c("gridNumber","Year"),type="full")
  </code></pre>
  
  <p>But R keeps crashing because I think the merge is a bit to large for it to handle, so I'm looking for something that would work better.  Maybe data.table?  Or another option.  </p>
  
  <p>Thanks for any help you can provide.</p>