Add Turning Timing On as a postgres til.

README.md

@@ -36,6 +36,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 ### postgres
 
 - [Timestamp Functions](postgres/timestamp-functions.md)
+- [Turning Timing On](postgres/turning-timing-on.md)
 
 ### rails
 

postgres/turn-timing-on.md

@@ -0,0 +1,9 @@
+# Turn Timing On
+
+When digging around your database and running queries, it is helpful to
+have an eye on the speed of those queries. This can give insight into
+where there are needs for optimizations.
+
+Turn timing on (and off) within `psql` by running `\timing`. With timing
+on, the duration of each query will be displayed in milliseconds after the
+output of the query.