Docs - add note regarding change in TRUNCATE behavior with foreign key
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-<topic id="topic1"><title id="ep20941">TRUNCATE</title><body><p id="sql_command_desc">Empties a table of all rows.</p><section id="section2"><title>Synopsis</title><codeblock id="sql_command_synopsis">TRUNCATE [TABLE] [ONLY] <varname>name</varname> [ * ] [, ...]
+<topic id="topic1"><title id="ep20941">TRUNCATE</title><body><p id="sql_command_desc">Empties a table of all rows.</p>
+ <note type="note">Greenplum Database does not enforce referential integrity syntax (foreign key
+ constraints). As of version 6.12 <codeph>TRUNCATE</codeph> truncates a table that is
+ referenced in a foreign key constraint even if the <codeph>CASCADE</codeph> option is
+ omitted.</note><section id="section2"><title>Synopsis</title><codeblock id="sql_command_synopsis">TRUNCATE [TABLE] [ONLY] <varname>name</varname> [ * ] [, ...]
[ RESTART IDENTITY | CONTINUE IDENTITY ] [CASCADE | RESTRICT]</codeblock></section>
<section id="section3"><title>Description</title><p><codeph>TRUNCATE</codeph> quickly removes
all rows from a table or set of tables. It has the same effect as an unqualified
