dear all, i am trying to understand if i am missing something on how vacuum works. i ve read the manual, and did some research on the web about that but i am still not sure. to my understanding, vacuum just marks the dead rows of a table so that from that point on that space would be re-used for new inserts and new updates on that specific table. however, if there is an open transaction, vacuum can only do what is described above up to the point that the open transaction was started. so if for example there is a query running for 1 day, no matter how many times i will have vacuumed the table (manual or auto), the dead rows wont be possible to be marked as re-usable space. -is the above correct? -is there something more about vacuum in that case i am describing? would for example mark the rows as 'semi-dead' so that when a scan would be made these rows wouldn't be checked and so the queries would be faster? is there anything else for this specific case? -would there be any effect from the vacuum on the indexes of the table?like i said above for the table, would the entries of the index not be scanned for a query, due to some reason? if there is a something i could read to answer these questions plz point me to that direction, otherwise i would really appreciate any information you may have. thx in advance -- View this message in context: http://postgresql.1045698.n5.nabble.com/vacuum-internals-and-performance-affect-tp5033043p5033043.html Sent from the PostgreSQL - performance mailing list archive at Nabble.com. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
