On 2017-10-01 04:09:19,"Alexander Korotkov" <a.korot...@postgrespro.ru> wrote:
On Sat, Sep 30, 2017 at 8:18 PM, chenhj <chjis...@163.com> wrote: On 2017-09-30 02:17:54，"Alexander Korotkov" <a.korot...@postgrespro.ru> wrote: 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. Your are rigth. I wrote a draft as following, but i'm afraid whether the english statement is accurate. I'm not native english speaker too :( Only the WAL files between the point of divergence and the current WAL insert location of the source server are copied, *for* other WAL files are useless for the target server. I'm not sure about this usage of word *for*. For me, it probably should be just removed. Rest of changes looks good for me. Please, integrate them into the patch. I had removed the *for* , Pleae check the new patch again. --- Best Regards, Chen Huajun
pg_rewind_wal_copy_reduce_v8.patch
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