Re: [GENERAL] About dropped notifications
CSN [EMAIL PROTECTED] writes: I'm considering setting up a script that listens for notifications for a table and if a row is deleted the script will delete that row's corresponding files. One way to deal with this would be to have a boolean flag in the table like deleted. Update that flag to true, and have a partial index where deleted. Then your daemon can quickly query select file_name where deleted, process the files and actually complete the deletion. All your other queries need to test where not deleted or go through a view with a clause like that. -- greg ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
Re: [GENERAL] About dropped notifications
CSN [EMAIL PROTECTED] writes: I'm considering setting up a script that listens for notifications for a table and if a row is deleted the script will delete that row's corresponding files. If there are thousands of rows in the table, and I do delete from table, or even delete from table where id 1000 and id2000, will the script be notified of the deletion of each and every row (and subsequently be able to delete that row's files), or will only one notify event be received (or some number less than the actual number of rows deleted)? Depends where you are doing the notify from ... but I think with the current implementation, a transaction will emit only one notify per notify event name, even if NOTIFY is executed many times within the transaction. regards, tom lane ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [GENERAL] About dropped notifications
[EMAIL PROTECTED] (Tom Lane) writes: CSN [EMAIL PROTECTED] writes: I'm considering setting up a script that listens for notifications for a table and if a row is deleted the script will delete that row's corresponding files. If there are thousands of rows in the table, and I do delete from table, or even delete from table where id 1000 and id2000, will the script be notified of the deletion of each and every row (and subsequently be able to delete that row's files), or will only one notify event be received (or some number less than the actual number of rows deleted)? Depends where you are doing the notify from ... but I think with the current implementation, a transaction will emit only one notify per notify event name, even if NOTIFY is executed many times within the transaction. An interesting question is whether or not the relevant tuple in pg_listener gets invalidated once, or whether doing 2500 attempted NOTIFY requests blows through 2500 copies. -- cbbrowne,@,cbbrowne.com http://www.ntlug.org/~cbbrowne/internet.html As long as each individual is facing the TV tube alone, formal freedom poses no threat to privilege. --Noam Chomsky ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
Re: [GENERAL] About dropped notifications
Chris Browne [EMAIL PROTECTED] writes: [EMAIL PROTECTED] (Tom Lane) writes: with the current implementation, a transaction will emit only one notify per notify event name, even if NOTIFY is executed many times within the transaction. An interesting question is whether or not the relevant tuple in pg_listener gets invalidated once, or whether doing 2500 attempted NOTIFY requests blows through 2500 copies. Once. (Per transaction...) regards, tom lane ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
