Add Find The Data Directory as a postgres til.

README.md

@@ -108,6 +108,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 - [Defining Arrays](postgres/defining-arrays.md)
 - [Edit Existing Functions](postgres/edit-existing-functions.md)
 - [Extracting Nested JSON Data](postgres/extracting-nested-json-data.md)
+- [Find The Data Directory](postgres/find-the-data-directory.md)
 - [Fizzbuzz With Common Table Expressions](postgres/fizzbuzz-with-common-table-expressions.md)
 - [Generate A UUID](postgres/generate-a-uuid.md)
 - [Generate Series Of Numbers](postgres/generate-series-of-numbers.md)

postgres/find-the-data-directory.md

@@ -0,0 +1,14 @@
+# Find The Data Directory
+
+Where does postgres store all of the data for a database cluster? Well, in
+its data directory. Where exactly that data directory is can depend on how
+the database cluster was setup. Postgres can tell you right where to look,
+though. Within `psql`, run
+
+```sql
+> show data_directory
+```
+
+Postgres will output the absolute path of the data directory.
+
+[source](http://dba.stackexchange.com/questions/1350/how-do-i-find-postgresqls-data-directory)