<p>Hi all.<p> I have read some codes on transaction abort operation. When the transaction abort, it seem that
<p>allthe tuples related in the transaction have not been deal with. it XMIN equals to the tuple create
transaction <p>ID.Its XMAX equals null. Of cource , It make some records on the pg_log.<p>So I have one question, how
thesystem know which tuple is valid? do it need the help of pg_log? That is<p>,we check for a tuple with XMIN is valid
andthe sign in pg_log means COMMIT?<p>Thank for any comments<p>Josh