note 67279 added to function.pg-last-oid

I am afraid that the editor is misleading people here. QUOTE "Editor's Note: If another record is inserted after the nextval is obtained and before you [sic: execute] the INSERT query this code will fail. This should not be done on busy sites." This is not correct. A sequence is a multi-session safe table-like structure in postgresql. From the postgresql manual for nextval() "Advance the sequence object to its next value and return that value. This is done atomically: even if multiple sessions execute nextval concurrently, each will safely receive a distinct sequence value. " Since the default for a serial column during an insert is to call nextval(), it will also get a unique identifier. Sequences are _not_ defined as being linearly ordered however and may contain holes and return values out of order (due to cache settings). They will, however, be unique 100% of the time. The following code is CORRECT and thread safe WITHOUT a transaction on even the most loaded server. QUOTE (with corrections) " $res=pg_query("SELECT nextval('foo_key_seq') as key"); $row=pg_fetch_array($res, 0); $key=$row['key']; // now we have the serial value in $key, let's do the insert pg_query("INSERT INTO foo (key, foo) VALUES ($key, 'blah blah')"); " In this case the value retrieved for $key will never again be retrieved by the database under any circumstance. Period. Ever. Hope that clears this up. ---- Server IP: 66.207.199.35 Probable Submitter: 142.179.200.164 ---- X-Spam-Status: No, hits=3.1 required=5.0 tests=DATE_MISSING,FROM_NO_LOWER autolearn=no version=2.64 ---- Manual Page -- http://www.php.net/manual/en/function.pg-last-oid.php Edit -- http://master.php.net/note/edit/67279 Del: integrated -- http://master.php.net/note/delete/67279/integrated Del: useless -- http://master.php.net/note/delete/67279/useless Del: bad code -- http://master.php.net/note/delete/67279/bad+code Del: spam -- http://master.php.net/note/delete/67279/spam Del: non-english -- http://master.php.net/note/delete/67279/non-english Del: in docs -- http://master.php.net/note/delete/67279/in+docs Del: other reasons-- http://master.php.net/note/delete/67279 Reject -- http://master.php.net/note/reject/67279 Search -- http://master.php.net/manage/user-notes.php