Re: New option for pg_basebackup, to specify a different directory for pg_xlog

<div class="WordSection1"><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">on
</span><spanstyle="font-size:10.0pt;font-family:"Tahoma","sans-serif"">15 November 2013 17:26 Magnus Hagander
wrote:</span><pclass="MsoNormal">>On Fri, Nov 15, 2013 at 12:10 PM, Haribabu kommi <<a
href="mailto:haribabu.kommi@huawei.com"target="_blank">haribabu.kommi@huawei.com</a>> wrote:<p class="MsoNormal"
style="margin-bottom:12.0pt">>On14 November 2013 23:59 Fujii Masao wrote:<br /> >> On Thu, Nov 14, 2013 at
9:08PM, Haribabu kommi<br /> >> <<a href="mailto:haribabu.kommi@huawei.com">haribabu.kommi@huawei.com</a>>
wrote:<br/> >> > Please find attached the patch, for adding a new option for<br /> >> >
pg_basebackup,to specify a different directory for pg_xlog.<br /> >>><br /> >> Sounds good! Here are the
reviewcomments:<br /> >>> Don't we need to prevent users from specifying the same directory in<br />
>>>both --pgdata and --xlogdir?<p class="MsoNormal">>>I feel no need to prevent, even if user specifies
both--pgdata and --xlogdir as same directory<br /> >>all the transaction log files will be created in the base
directoryinstead of pg_xlog directory.<p class="MsoNormal"> <p class="MsoNormal">>Given how easy it would be to
preventthat, I think we should. It would be an easy misunderstanding to specify that when you actually want it in
<wherever>/pg_xlog.Specifying that would be redundant in the first place, but people ca do that, but it <p
class="MsoNormal">>wouldalso be very easy to do it by mistake, and you'd end up with something that's really bad,
includinga recursive symlink.<p class="MsoNormal"> <p class="MsoNormal">Presently with initdb also user can specify
bothdata and xlog directories as same.<p class="MsoNormal">To prevent the data directory and xlog directory as same,
thereis a way in windows (_fullpath api) to get absolute path from a relative path, but I didn’t get any such
possibilitiesin linux.<p class="MsoNormal">I didn’t find any other way to check it, if anyone have any idea regarding
thisplease let me know.<p class="MsoNormal"> <p class="MsoNormal">>I also think it would probably be worthwhile to
supportthis in  tar format as well, but I guess that's a separate patch really. There's really no reason we should't
supportwal streaming into a separate tar file. But - separate issue.<p class="MsoNormal"> <p class="MsoNormal">Sure. I
willprepare a separate patch for the same and submit it in the next commit fest.<p class="MsoNormal"> <p
class="MsoNormal">Regards,<pclass="MsoNormal">Hari babu.<br clear="all" /><p class="MsoNormal"></div>