Hi, On 2014-01-14 21:47:43 +0900, Michael Paquier wrote: > I would like to propose the following things to extend BASE_BACKUP to > retrieve a backup from a stream: > - Addition of an option FORMAT, to control the output format of > backup, with possible options as 'plain' and 'tar'. Default is tar for > backward compatibility purposes. The purpose of this option is to make > easier for backup tools playing with postgres to retrieve and backup > and analyze it on the fly, the purpose being to filter and analyze the > data while it is being received without all the tar decoding > necessary, what would consist in copying portions of pg_basebackup > code more or less.
We'd need our own serialization format since we're dealing with more than one file, what would be the point? > - Addition of an option called INCREMENTAL to send an incremental > backup to the client. This option uses as input an LSN, and sends back > to client relation pages (in the shape of reduced relation files) that > are newer than the LSN specified by looking at pd_lsn of > PageHeaderData. In this case the LSN needs to be determined by client > based on the latest full backup taken. This option is particularly > interesting to reduce the amount of data taken between two backups, > even if it increases the restore time as client needs to reconstitute > a base backup depending on the recovery target and the pages modified. > Client would be in charge of rebuilding pages from incremental backup > by scanning all the blocks that need to be updated based on the full > backup as the LSN from which incremental backup is taken is known. But > this is not really something the server cares about... Such things are > actually done by pg_rman as well. Why not just rely on WAL replay since you're relying on the consistency of the standby anyway? Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
