Fix "the the" typos.

Erik Rijkers

doc/src/sgml/json.sgml

@@ -24,7 +24,7 @@
   There are two JSON data types: <type>json</> and <type>jsonb</>.
   Both accept <emphasis>almost</emphasis> identical sets of values as
   input.  The major practical difference is one of efficiency.  The
-  <type>json</> data type stores an exact copy of the the input text,
+  <type>json</> data type stores an exact copy of the input text,
   which processing functions must continually reparse, while
   <type>jsonb</> data is stored in a decomposed binary format that
   makes it slightly less efficient to input due to added serialization

doc/src/sgml/logicaldecoding.sgml

@@ -169,7 +169,7 @@ CTRL-C
     </indexterm>
     <title>Logical Decoding</title>
     <para>
-     Logical decoding is the the process of extracting all persistent changes
+     Logical decoding is the process of extracting all persistent changes
      to a database's tables into a coherent, easy to understand format which
      can be interpreted without detailed knowledge of the database's internal
      state.

src/backend/access/transam/xlog.c

@@ -1089,7 +1089,7 @@ begin:;
 	 * has progressed. There is a small fixed number of insertion locks,
 	 * determined by the num_xloginsert_locks GUC. When an inserter crosses a
 	 * page boundary, it updates the value stored in the lock to the how far it
-	 * has inserted, to allow the the previous buffer to be flushed.
+	 * has inserted, to allow the previous buffer to be flushed.
 	 *
 	 * Holding onto an insertion lock also protects RedoRecPtr and
 	 * fullPageWrites from changing until the insertion is finished.