On Fri, Sep 29, 2017 at 8:10 PM, chenhj <chjis...@163.com> wrote: > On 2017-09-30 00:53:31，"chenhj" <chjis...@163.com> wrote: > > On 2017-09-29 19:29:40，"Alexander Korotkov" <a.korot...@postgrespro.ru> > wrote: > > On Fri, Sep 29, 2017 at 10:07 AM, chenhj <chjis...@163.com> wrote: >> >> >> > OK. That makes sense. Thank you for the explanation. > > I still have some minor comments. > > >> /* >> + * Save the WAL filenames of the divergence and the current WAL insert >> + * location of the source server. Later only the WAL files between >> those >> + * would be copied to the target data directory. >> > > Comment is outdated. We don't save filenames anymore, now we save segment > numbers. > > >> + * Note:The later generated WAL files in the source server before the >> end >> + * of the copy of the data files must be made available when the >> target >> + * server is started. This can be done by configuring the target >> server as >> + * a standby of the source server. >> + */ > > > You miss space after "Note:". Also, it seems reasonable for me to leave > empty line before "Note:". > > # Setup parameter for WAL reclaim > > > Parameter*s*, because you're setting up multiple of them. > > # The accuracy of imodification from pg_ls_waldir() is seconds, so sleep >> one seconds > > > One second without "s". > > Also, please check empty lines in 006_wal_copy.pl to be just empty lines > without tabs. > > > Thanks for your comments, i had fix above problems. > And also add several line breaks at long line in 006_wal_copy.pl > Please check this patch again. > > > Sorry, patch v6 did not remove tabs in two empty lines, please use the new > one. >
Great. Now code of this patch looks good for me. However, we forgot about documentation. <para> > The result is equivalent to replacing the target data directory with the > source one. Only changed blocks from relation files are copied; > all other files are copied in full, including configuration files. The > advantage of <application>pg_rewind</> over taking a new base backup, or > tools like <application>rsync</>, is that <application>pg_rewind</> does > not require reading through unchanged blocks in the cluster. This makes > it a lot faster when the database is large and only a small > fraction of blocks differ between the clusters. > </para> At least, this paragraph need to be adjusted, because it states whose files are copied. And probably latter paragraphs whose state about WAL files. ------ Alexander Korotkov Postgres Professional: http://www.postgrespro.com The Russian Postgres Company
